Fix cif2pdb, somewhat...

don't use get_item_indices
version bump

.clang-format

@@ -0,0 +1,22 @@
+BasedOnStyle: LLVM
+UseTab: AlignWithSpaces
+IndentWidth: 4
+TabWidth: 4
+BreakBeforeBraces: Allman
+ColumnLimit: 0
+NamespaceIndentation: Inner
+FixNamespaceComments: true
+AccessModifierOffset: -2
+AllowShortCaseLabelsOnASingleLine: true
+IndentCaseLabels: true
+BreakConstructorInitializers: BeforeComma
+BraceWrapping:
+  BeforeLambdaBody: false
+AlignAfterOpenBracket: DontAlign
+Cpp11BracedListStyle: false
+IncludeBlocks: Regroup
+LambdaBodyIndentation: Signature
+AllowShortLambdasOnASingleLine: Inline
+EmptyLineBeforeAccessModifier: LogicalBlock
+IndentPPDirectives: AfterHash
+PPIndentWidth: 1

.clang-tidy

@@ -0,0 +1,18 @@
+Checks: '-*,
+         bugprone-*,
+         -bugprone-easily-swappable-parameters,
+         cert-*,
+         modernize*,
+         -modernize-use-trailing-return-type,
+         -modernize-avoid-c-arrays,
+         -modernize-use-designated-initializers,
+         performance
+         '
+
+# HeaderFilterRegex: '.*'
+ExcludeHeaderFilterRegex: 'Eigen|Eigen/Eigenvalues|eigen3/Eigen/Eigenvalues|sqlite3.h'
+CheckOptions:
+  - key: bugprone-narrowing-conversions.WarnOnIntegerNarrowingConversion
+    value: false
+  - key: bugprone-narrowing-conversions.WarnOnIntegerToFloatingPointNarrowingConversion
+    value: false

.github/workflows/build-documentation.yml

@@ -42,7 +42,7 @@ jobs:
 
     - name: Run Sphinx
       run: |
-        cmake --build ${{ steps.strings.outputs.build-output-dir }} --target Sphinx-libcifpp
+        cmake --build ${{ steps.strings.outputs.build-output-dir }} --target Sphinx-cifpp
         ls -l ${{ steps.strings.outputs.build-output-dir }}
         ls -l ${{ steps.strings.outputs.build-output-dir }}/docs/sphinx
 

.github/workflows/cmake-multi-platform.yml

@@ -33,13 +33,18 @@ jobs:
 
     - name: Install dependencies Ubuntu
       if: matrix.os == 'ubuntu-latest'
-      run: sudo apt-get update && sudo apt-get install mrc
+      run: sudo apt-get update && sudo apt-get install mrc catch2 libsqlite3-dev
 
     - name: Install dependencies Window
       if: matrix.os == 'windows-latest'
       run: ./tools/depends.cmd
       shell: cmd
 
+    - name: Install Catch2 macOS
+      if: matrix.os == 'macos-latest'
+      run: >
+        brew install catch2 fast_float
+
     - name: Configure CMake
       run: >
         cmake -B ${{ steps.strings.outputs.build-output-dir }}

.gitignore

@@ -14,3 +14,5 @@ docs/conf.py
 build_ci/
 data/components.cif
 perf.data*
+.cache/
+

.readthedocs.yaml

@@ -1,22 +0,0 @@
-version: 2
-
-build:
-  os: ubuntu-22.04
-  tools:
-    python: "3.11"
-  apt_packages:
-    - doxygen
-    - cmake
-  jobs:
-    pre_build:
-      - cmake -S . -B build -DBUILD_DOCUMENTATION=ON
-      - cmake --build build --target Doxygen
-
-# Build from the docs/ directory with Sphinx
-sphinx:
-  configuration: docs/conf.py
-
-# Explicitly set the version of Python and its requirements
-python:
-  install:
-    - requirements: docs/requirements.txt

CMakeLists.txt

@@ -24,16 +24,18 @@
 
 cmake_minimum_required(VERSION 3.23)
 
+cmake_policy(SET CMP0135 NEW)
+
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR AND NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
-	set(CMAKE_BUILD_TYPE Release CACHE STRING "Build type" FORCE)
-	set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release" "MinSizeRel" "RelWithDebInfo")
+    set(CMAKE_BUILD_TYPE Release CACHE STRING "Build type" FORCE)
+    set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release" "MinSizeRel" "RelWithDebInfo")
 endif()
 
 # set the project name
 project(
-	libcifpp
-	VERSION 9.0.0
-	LANGUAGES CXX)
+    libcifpp
+    VERSION 10.0.4
+    LANGUAGES CXX C)
 
 list(PREPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 
@@ -43,141 +45,157 @@ include(GenerateExportHeader)
 include(CTest)
 include(ExternalProject)
 include(FetchContent)
-include(CPM)
+include(VersionString)
 
 # When building with ninja-multiconfig, build both debug and release by default
 if(CMAKE_GENERATOR STREQUAL "Ninja Multi-Config")
-	set(CMAKE_CROSS_CONFIGS "Debug;Release")
-	set(CMAKE_DEFAULT_CONFIGS "Debug;Release")
+    set(CMAKE_CROSS_CONFIGS "Debug;Release")
+    set(CMAKE_DEFAULT_CONFIGS "Debug;Release")
 endif()
 
 if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
-	set(CMAKE_CXX_FLAGS
-		"${CMAKE_CXX_FLAGS} -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers"
-	)
+    set(CMAKE_CXX_FLAGS
+        "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers"
+    )
 elseif(MSVC)
-	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W4")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W4")
 endif()
 
 # Build documentation?
 set(BUILD_DOCUMENTATION OFF CACHE BOOL "Build the documentation")
 
+# Build examples?
+set(BUILD_EXAMPLES ON CACHE BOOL "Build the example applications")
+
 # Optionally build a version to be installed inside CCP4
 set(BUILD_FOR_CCP4 OFF CACHE BOOL "Build a version to be installed in CCP4")
 
+# Create the cql/sqlite interface
+set(BUILD_SQLITE_INTERFACE ON CACHE BOOL "Build the sqlite interface")
+
 # Building shared libraries?
-if(NOT(BUILD_FOR_CCP4 AND WIN32))
-	set(BUILD_SHARED_LIBS OFF CACHE BOOL "Build a shared library instead of a static one")
+if(NOT (BUILD_FOR_CCP4 AND WIN32))
+    set(BUILD_SHARED_LIBS OFF CACHE BOOL "Build a shared library instead of a static one")
 endif()
 
 if(PROJECT_IS_TOP_LEVEL AND NOT BUILD_FOR_CCP4)
-	# Lots of code depend on the availability of the components.cif file
-	set(CIFPP_DOWNLOAD_CCD ON CACHE BOOL "Download the CCD file components.cif during installation")
+    # Lots of code depend on the availability of the components.cif file
+    set(CIFPP_DOWNLOAD_CCD ON CACHE BOOL "Download the CCD file components.cif during installation")
 
-	# An optional cron script can be installed to keep the data files up-to-date
-	if(UNIX AND NOT APPLE)
-		set(CIFPP_INSTALL_UPDATE_SCRIPT ON CACHE BOOL "Install the script to update CCD and dictionary files")
-	endif()
+    # An optional cron script can be installed to keep the data files up-to-date
+    if(UNIX AND NOT APPLE)
+        set(CIFPP_INSTALL_UPDATE_SCRIPT ON CACHE BOOL "Install the script to update CCD and dictionary files")
+    endif()
 else()
-	unset(CIFPP_DOWNLOAD_CCD)
-	unset(CIFPP_INSTALL_UPDATE_SCRIPT)
+    unset(CIFPP_DOWNLOAD_CCD)
+    unset(CIFPP_INSTALL_UPDATE_SCRIPT)
 endif()
 
 # When CCP4 is sourced in the environment, we can recreate the symmetry
 # operations table
 if(EXISTS "$ENV{CCP4}/lib/data/syminfo.lib")
-	set(CIFPP_RECREATE_SYMOP_DATA ON CACHE BOOL "Recreate SymOp data table in case it is out of date")
+    set(CIFPP_RECREATE_SYMOP_DATA ON CACHE BOOL "Recreate SymOp data table in case it is out of date")
 endif()
 
 # CCP4 build
 if(BUILD_FOR_CCP4)
-	if("$ENV{CCP4}" STREQUAL "" OR NOT EXISTS $ENV{CCP4})
-		message(FATAL_ERROR "cifpp: A CCP4 built was requested but CCP4 was not sourced")
-	else()
-		list(PREPEND CMAKE_MODULE_PATH "$ENV{CCP4}")
-		list(PREPEND CMAKE_PREFIX_PATH "$ENV{CCP4}")
-		set(CMAKE_INSTALL_PREFIX "$ENV{CCP4}")
+    if("$ENV{CCP4}" STREQUAL "" OR NOT EXISTS $ENV{CCP4})
+        message(FATAL_ERROR "cifpp: A CCP4 built was requested but CCP4 was not sourced")
+    else()
+        list(PREPEND CMAKE_MODULE_PATH "$ENV{CCP4}")
+        list(PREPEND CMAKE_PREFIX_PATH "$ENV{CCP4}")
+        set(CMAKE_INSTALL_PREFIX "$ENV{CCP4}")
 
-		if(WIN32)
-			set(BUILD_SHARED_LIBS ON)
-		endif()
-	endif()
+        if(WIN32)
+            set(BUILD_SHARED_LIBS ON)
+        endif()
+    endif()
 endif()
 
 # Now include the GNUInstallDirs module
 include(GNUInstallDirs)
 
 if(WIN32)
-	if(${CMAKE_SYSTEM_VERSION} GREATER_EQUAL 10) # Windows 10
-		add_definitions(-D _WIN32_WINNT=0x0A00)
-	elseif(${CMAKE_SYSTEM_VERSION} EQUAL 6.3) # Windows 8.1
-		add_definitions(-D _WIN32_WINNT=0x0603)
-	elseif(${CMAKE_SYSTEM_VERSION} EQUAL 6.2) # Windows 8
-		add_definitions(-D _WIN32_WINNT=0x0602)
-	elseif(${CMAKE_SYSTEM_VERSION} EQUAL 6.1) # Windows 7
-		add_definitions(-D _WIN32_WINNT=0x0601)
-	elseif(${CMAKE_SYSTEM_VERSION} EQUAL 6.0) # Windows Vista
-		add_definitions(-D _WIN32_WINNT=0x0600)
-	else() # Windows XP (5.1)
-		add_definitions(-D _WIN32_WINNT=0x0501)
-	endif()
+    if(${CMAKE_SYSTEM_VERSION} GREATER_EQUAL 10) # Windows 10
+        add_definitions(-D _WIN32_WINNT=0x0A00)
+    elseif(${CMAKE_SYSTEM_VERSION} EQUAL 6.3) # Windows 8.1
+        add_definitions(-D _WIN32_WINNT=0x0603)
+    elseif(${CMAKE_SYSTEM_VERSION} EQUAL 6.2) # Windows 8
+        add_definitions(-D _WIN32_WINNT=0x0602)
+    elseif(${CMAKE_SYSTEM_VERSION} EQUAL 6.1) # Windows 7
+        add_definitions(-D _WIN32_WINNT=0x0601)
+    elseif(${CMAKE_SYSTEM_VERSION} EQUAL 6.0) # Windows Vista
+        add_definitions(-D _WIN32_WINNT=0x0600)
+    else() # Windows XP (5.1)
+        add_definitions(-D _WIN32_WINNT=0x0501)
+    endif()
 
-	# We do not want to write an export file for all our symbols...
-	set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
+    # We do not want to write an export file for all our symbols...
+    set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
 endif()
 
 if(MSVC)
-	# make msvc standards compliant...
-	add_compile_options(/permissive- /bigobj)
-	add_link_options(/NODEFAULTLIB:library)
-
-	# This is dubious...
-	if(BUILD_SHARED_LIBS)
-		set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>DLL")
-	else()
-		set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
-	endif()
+    # make msvc standards compliant...
+    add_compile_options(/permissive- /bigobj)
+    add_link_options(/NODEFAULTLIB:library)
 endif()
 
 # Libraries
 
 if(MSVC)
-	# Avoid linking the shared library of zlib. Search ZLIB_ROOT first if it is
-	# set.
-	if(ZLIB_ROOT)
-		set(_ZLIB_SEARCH_ROOT PATHS ${ZLIB_ROOT} NO_DEFAULT_PATH)
-		list(APPEND _ZLIB_SEARCHES _ZLIB_SEARCH_ROOT)
-	endif()
+    # Avoid linking the shared library of zlib. Search ZLIB_ROOT first if it is
+    # set.
+    if(ZLIB_ROOT)
+        set(_ZLIB_SEARCH_ROOT PATHS ${ZLIB_ROOT} NO_DEFAULT_PATH)
+        list(APPEND _ZLIB_SEARCHES _ZLIB_SEARCH_ROOT)
+    endif()
 
-	# Normal search.
-	set(_ZLIB_x86 "(x86)")
-	set(_ZLIB_SEARCH_NORMAL
-		PATHS "[HKEY_LOCAL_MACHINE\\SOFTWARE\\GnuWin32\\Zlib;InstallPath]"
-		"$ENV{ProgramFiles}/zlib" "$ENV{ProgramFiles${_ZLIB_x86}}/zlib")
-	unset(_ZLIB_x86)
-	list(APPEND _ZLIB_SEARCHES _ZLIB_SEARCH_NORMAL)
+    # Normal search.
+    set(_ZLIB_x86 "(x86)")
+    set(_ZLIB_SEARCH_NORMAL
+        PATHS "[HKEY_LOCAL_MACHINE\\SOFTWARE\\GnuWin32\\Zlib;InstallPath]"
+        "$ENV{ProgramFiles}/zlib" "$ENV{ProgramFiles${_ZLIB_x86}}/zlib")
+    unset(_ZLIB_x86)
+    list(APPEND _ZLIB_SEARCHES _ZLIB_SEARCH_NORMAL)
 
-	if(BUILD_FOR_CCP4)
-		list(PREPEND _ZLIB_SEARCHES "$ENV{CCP4}/lib")
-	endif()
+    if(BUILD_FOR_CCP4)
+        list(PREPEND _ZLIB_SEARCHES "$ENV{CCP4}/lib")
+    endif()
 
-	foreach(search ${_ZLIB_SEARCHES})
-		find_library(
-			ZLIB_LIBRARY
-			NAMES zlibstatic NAMES_PER_DIR ${${search}}
-			PATH_SUFFIXES lib)
-	endforeach()
+    foreach(search ${_ZLIB_SEARCHES})
+        find_library(
+            ZLIB_LIBRARY
+            NAMES zlibstatic NAMES_PER_DIR ${${search}}
+            PATH_SUFFIXES lib)
+    endforeach()
 endif()
 
-# find_package(pcre2) is unfortunately broken 
+# Using fast_float for float parsing, but only if needed
+try_compile(STD_CHARCONV_COMPILING
+    SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/cmake/test-charconv.cpp
+    CXX_STANDARD 20
+    CXX_STANDARD_REQUIRED ON)
 
-include(FindPCRE2x)
+if(NOT STD_CHARCONV_COMPILING)
+    message(NOTICE "libcifpp: Using fast_float for std::from_chars")
+    find_package(FastFloat 8.0 REQUIRED CONFIG)
+endif()
 
-find_package(ZLIB QUIET)
 find_package(Threads)
+find_package(ZLIB QUIET)
 
 if(NOT ZLIB_FOUND)
-	message(FATAL_ERROR "cifpp: The zlib development files were not found you this system, please install them and try again (hint: on debian/ubuntu use apt-get install zlib1g-dev)")
+    message(FATAL_ERROR "cifpp: The zlib development files were not found you this system, please install them and try again (hint: on debian/ubuntu use apt-get install zlib1g-dev)")
+endif()
+
+include(FindPkgConfig)
+
+if(PKG_CONFIG_FOUND)
+    pkg_check_modules(PCRE2 IMPORTED_TARGET libpcre2-8)
+endif()
+
+if(NOT PCRE2_FOUND)
+    add_subdirectory(pcre2-simple)
 endif()
 
 # Using Eigen3 is a bit of a thing. We don't want to build it completely since
@@ -186,346 +204,375 @@ endif()
 find_package(Eigen3 3.4 QUIET)
 
 if(Eigen3_FOUND AND TARGET Eigen3::Eigen)
-	get_target_property(EIGEN_INCLUDE_DIR Eigen3::Eigen
-		INTERFACE_INCLUDE_DIRECTORIES)
+    get_target_property(EIGEN_INCLUDE_DIR Eigen3::Eigen
+        INTERFACE_INCLUDE_DIRECTORIES)
 else()
-	# Use ExternalProject since FetchContent always tries to install the result...
-	ExternalProject_Add(my-eigen3
-		GIT_REPOSITORY https://gitlab.com/libeigen/eigen.git
-		GIT_TAG 3.4.0
-		INSTALL_COMMAND "")
+    # Use ExternalProject since FetchContent always tries to install the result...
+    ExternalProject_Add(my-eigen3
+        URL https://gitlab.com/libeigen/eigen/-/archive/3.4.0/eigen-3.4.0.zip
+        DOWNLOAD_EXTRACT_TIMESTAMP TRUE
+        CONFIGURE_COMMAND ""
+        BUILD_COMMAND ""
+        INSTALL_COMMAND "")
 
-	ExternalProject_Get_Property(my-eigen3 SOURCE_DIR)
-	set(EIGEN_INCLUDE_DIR ${SOURCE_DIR})
+    ExternalProject_Get_Property(my-eigen3 SOURCE_DIR)
+    set(EIGEN_INCLUDE_DIR ${SOURCE_DIR})
 endif()
 
-message(STATUS "cifpp: Eigen include dir is ${EIGEN_INCLUDE_DIR}")
-
-# Create a revision file, containing the current git version info
-include(VersionString)
-write_version_header(${CMAKE_CURRENT_SOURCE_DIR}/src/ LIB_NAME "LibCIFPP")
-
 # SymOp data table
 if(CIFPP_RECREATE_SYMOP_DATA)
-	# The tool to create the table
-	add_executable(symop-map-generator
-		"${CMAKE_CURRENT_SOURCE_DIR}/src/symop-map-generator.cpp")
+    # The tool to create the table
+    add_executable(symop-map-generator
+        "${CMAKE_CURRENT_SOURCE_DIR}/src/symop-map-generator.cpp")
 
-	target_compile_features(symop-map-generator PUBLIC cxx_std_20)
+    target_compile_features(symop-map-generator PUBLIC cxx_std_20)
 
-	add_custom_command(
-		OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/src/symop_table_data.hpp
-		COMMAND
-		$<TARGET_FILE:symop-map-generator> $ENV{CLIBD}/syminfo.lib
-		$ENV{CLIBD}/symop.lib ${CMAKE_CURRENT_SOURCE_DIR}/src/symop_table_data.hpp)
+    add_custom_command(
+        OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/src/symop_table_data.hpp
+        COMMAND
+        $<TARGET_FILE:symop-map-generator> $ENV{CLIBD}/syminfo.lib
+        $ENV{CLIBD}/symop.lib ${CMAKE_CURRENT_SOURCE_DIR}/src/symop_table_data.hpp)
 
-	add_custom_target(
-		OUTPUT
-		${CMAKE_CURRENT_SOURCE_DIR}/src/symop_table_data.hpp
-		DEPENDS symop-map-generator "$ENV{CLIBD}/syminfo.lib"
-		"$ENV{CLIBD}/symop.lib")
+    add_custom_target(
+        OUTPUT
+        ${CMAKE_CURRENT_SOURCE_DIR}/src/symop_table_data.hpp
+        DEPENDS symop-map-generator "$ENV{CLIBD}/syminfo.lib"
+        "$ENV{CLIBD}/symop.lib")
 endif()
 
-# Sources
-set(project_sources
-	${CMAKE_CURRENT_SOURCE_DIR}/src/category.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/condition.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/datablock.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/dictionary_parser.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/file.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/item.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/parser.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/row.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/validate.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/text.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/utilities.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/atom_type.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/compound.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/point.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/symmetry.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/model.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/cif2pdb.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/pdb2cif.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/pdb_record.hpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/pdb2cif_remark_3.hpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/pdb2cif_remark_3.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/reconstruct.cpp
-	${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/validate-pdbx.cpp
-)
-
-set(project_headers
-	include/cif++.hpp
-	include/cif++/atom_type.hpp
-	include/cif++/category.hpp
-	include/cif++/compound.hpp
-	include/cif++/condition.hpp
-	include/cif++/datablock.hpp
-	include/cif++/dictionary_parser.hpp
-	include/cif++/exports.hpp
-	include/cif++/file.hpp
-	include/cif++/format.hpp
-	include/cif++/forward_decl.hpp
-	include/cif++/gzio.hpp
-	include/cif++/item.hpp
-	include/cif++/iterator.hpp
-	include/cif++/matrix.hpp
-	include/cif++/model.hpp
-	include/cif++/parser.hpp
-	include/cif++/pdb/cif2pdb.hpp
-	include/cif++/pdb.hpp
-	include/cif++/pdb/io.hpp
-	include/cif++/pdb/pdb2cif.hpp
-	include/cif++/pdb/tls.hpp
-	include/cif++/point.hpp
-	include/cif++/row.hpp
-	include/cif++/symmetry.hpp
-	include/cif++/text.hpp
-	include/cif++/utilities.hpp
-	include/cif++/validate.hpp
-)
+# Create a revision file, containing the current git version info
+write_version_header("${CMAKE_CURRENT_SOURCE_DIR}/src/" LIB_NAME "LibCIFPP")
 
 add_library(cifpp)
 add_library(cifpp::cifpp ALIAS cifpp)
 
+# Sources
+list(APPEND project_sources
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/category.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/condition.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/datablock.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/dictionary_parser.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/file.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/item.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/parser.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/row.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/validate.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/text.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/utilities.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/atom_type.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/compound.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/point.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/symmetry.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/model.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/cif2pdb.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/pdb2cif.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/pdb_record.hpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/pdb2cif_remark_3.hpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/pdb2cif_remark_3.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/reconstruct.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/pdb/validate-pdbx.cpp
+)
+
+list(APPEND project_headers
+    include/cif++.hpp
+    include/cif++/cif++.hpp
+    include/cif++/atom_type.hpp
+    include/cif++/category.hpp
+    include/cif++/compound.hpp
+    include/cif++/condition.hpp
+    include/cif++/datablock.hpp
+    include/cif++/dictionary_parser.hpp
+    include/cif++/exports.hpp
+    include/cif++/file.hpp
+    include/cif++/format.hpp
+    include/cif++/gzio.hpp
+    include/cif++/item.hpp
+    include/cif++/iterator.hpp
+    include/cif++/matrix.hpp
+    include/cif++/model.hpp
+    include/cif++/parser.hpp
+    include/cif++/pdb.hpp
+    include/cif++/point.hpp
+    include/cif++/row.hpp
+    include/cif++/symmetry.hpp
+    include/cif++/text.hpp
+    include/cif++/utilities.hpp
+    include/cif++/validate.hpp
+)
+
+if(BUILD_SQLITE_INTERFACE)
+    find_package(SQLite3 QUIET)
+    if(SQLite3_FOUND)
+        target_link_libraries(cifpp PRIVATE SQLite::SQLite3)
+    else()
+        FetchContent_Populate(SQLite3
+            URL https://sqlite.org/2025/sqlite-amalgamation-3510100.zip
+            URL_HASH SHA3_256=856b52ffe7383d779bb86a0ed1ddc19c41b0e5751fa14ce6312f27534e629b64
+            EXCLUDE_FROM_ALL)
+
+        list(APPEND project_sources $<BUILD_INTERFACE:${sqlite3_SOURCE_DIR}>/sqlite3.c)
+        target_include_directories(cifpp PRIVATE $<BUILD_INTERFACE:${sqlite3_SOURCE_DIR}>)
+    endif()
+
+    list(APPEND project_sources ${CMAKE_CURRENT_SOURCE_DIR}/src/cql.cpp)
+    list(APPEND project_headers include/cif++/cql.hpp)
+endif()
+
 if(TARGET my-eigen3)
-	add_dependencies(cifpp my-eigen3)
+    add_dependencies(cifpp my-eigen3)
 endif()
 
 target_sources(cifpp
-	PRIVATE ${project_sources}
-	${CMAKE_CURRENT_SOURCE_DIR}/src/symop_table_data.hpp
-	PUBLIC
-	FILE_SET cifpp_headers TYPE HEADERS
-	BASE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/include
-	FILES ${project_headers}
+    PRIVATE ${project_sources}
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/symop_table_data.hpp
+    PUBLIC
+    FILE_SET cifpp_headers TYPE HEADERS
+    BASE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/include
+    FILES ${project_headers}
 )
 
 # The code now really requires C++20
-target_compile_features(cifpp PUBLIC cxx_std_20)
+target_compile_features(cifpp PUBLIC cxx_std_23)
 
 generate_export_header(cifpp EXPORT_FILE_NAME
-	${CMAKE_CURRENT_SOURCE_DIR}/include/cif++/exports.hpp)
+    ${CMAKE_CURRENT_SOURCE_DIR}/include/cif++/exports.hpp)
 
 if(MSVC)
-	target_compile_definitions(cifpp PUBLIC NOMINMAX=1)
+    target_compile_definitions(cifpp PUBLIC NOMINMAX=1)
 endif()
 
 set_target_properties(cifpp PROPERTIES POSITION_INDEPENDENT_CODE ON)
 
 target_include_directories(
-	cifpp
-	PUBLIC "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
-	"$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>"
-	PRIVATE "${EIGEN_INCLUDE_DIR}")
+    cifpp
+    PUBLIC "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
+    "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>"
+    PRIVATE "${EIGEN_INCLUDE_DIR}")
 
 target_link_libraries(cifpp
-	PUBLIC Threads::Threads ZLIB::ZLIB $<$<TARGET_EXISTS:std::atomic>:std::atomic>
-	PRIVATE $<BUILD_INTERFACE:pcre2-8>)
+    PUBLIC Threads::Threads ZLIB::ZLIB $<$<TARGET_EXISTS:std::atomic>:std::atomic>)
+
+if(PCRE2_FOUND)
+    target_include_directories(cifpp PRIVATE ${PCRE2_INCLUDE_DIRS})
+    target_link_libraries(cifpp PRIVATE ${PCRE2_LINK_LIBRARIES})
+else()
+    target_link_libraries(cifpp PRIVATE $<BUILD_INTERFACE:pcre2s>)
+endif()
+
+if(NOT STD_CHARCONV_COMPILING)
+    get_target_property(FF_INC_DIR FastFloat::fast_float INTERFACE_INCLUDE_DIRECTORIES)
+    target_include_directories(cifpp PRIVATE ${FF_INC_DIR})
+	target_compile_definitions(cifpp PRIVATE USE_FAST_FLOAT)
+endif()
 
 if(CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
-	target_link_options(cifpp PRIVATE -undefined dynamic_lookup)
+    target_link_options(cifpp PRIVATE -undefined dynamic_lookup)
 endif(CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
 
 if(CIFPP_DOWNLOAD_CCD)
-	# download the components.cif file from CCD
-	set(COMPONENTS_CIF ${CMAKE_CURRENT_SOURCE_DIR}/rsrc/components.cif)
+    # download the components.cif file from CCD
+    set(COMPONENTS_CIF ${CMAKE_CURRENT_SOURCE_DIR}/rsrc/components.cif)
 
-	if(EXISTS ${COMPONENTS_CIF})
-		file(SIZE ${COMPONENTS_CIF} CCD_FILE_SIZE)
+    if(EXISTS ${COMPONENTS_CIF})
+        file(SIZE ${COMPONENTS_CIF} CCD_FILE_SIZE)
 
-		if(CCD_FILE_SIZE EQUAL 0)
-			message(STATUS "cifpp: Removing empty ${COMPONENTS_CIF} file")
-			file(REMOVE "${COMPONENTS_CIF}")
-		endif()
-	endif()
+        if(CCD_FILE_SIZE EQUAL 0)
+            message(STATUS "cifpp: Removing empty ${COMPONENTS_CIF} file")
+            file(REMOVE "${COMPONENTS_CIF}")
+        endif()
+    endif()
 
-	if(NOT EXISTS ${COMPONENTS_CIF})
-		# Since the file(DOWNLOAD) command in cmake does not use compression, we try
-		# to download the gzipped version and decompress it ourselves.
-		find_program(GUNZIP gunzip)
+    if(NOT EXISTS ${COMPONENTS_CIF})
+        # Since the file(DOWNLOAD) command in cmake does not use compression, we try
+        # to download the gzipped version and decompress it ourselves.
+        find_program(GUNZIP gunzip)
 
-		if(WIN32 OR GUNZIP STREQUAL "GUNZIP-NOTFOUND")
-			file(
-				DOWNLOAD https://files.wwpdb.org/pub/pdb/data/monomers/components.cif
-				${COMPONENTS_CIF}
-				SHOW_PROGRESS
-				STATUS CCD_FETCH_STATUS)
-		else()
-			if(NOT EXISTS "${COMPONENTS_CIF}.gz")
-				file(
-					DOWNLOAD
-					https://files.wwpdb.org/pub/pdb/data/monomers/components.cif.gz
-					${COMPONENTS_CIF}.gz
-					SHOW_PROGRESS
-					STATUS CCD_FETCH_STATUS)
-			endif()
+        if(WIN32 OR GUNZIP STREQUAL "GUNZIP-NOTFOUND")
+            file(
+                DOWNLOAD https://files.wwpdb.org/pub/pdb/data/monomers/components.cif
+                ${COMPONENTS_CIF}
+                SHOW_PROGRESS
+                STATUS CCD_FETCH_STATUS)
+        else()
+            if(NOT EXISTS "${COMPONENTS_CIF}.gz")
+                file(
+                    DOWNLOAD
+                    https://files.wwpdb.org/pub/pdb/data/monomers/components.cif.gz
+                    ${COMPONENTS_CIF}.gz
+                    SHOW_PROGRESS
+                    STATUS CCD_FETCH_STATUS)
+            endif()
 
-			add_custom_command(
-				OUTPUT ${COMPONENTS_CIF}
-				COMMAND "${GUNZIP}" ${COMPONENTS_CIF}.gz
-				WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/rsrc/)
+            add_custom_command(
+                OUTPUT ${COMPONENTS_CIF}
+                COMMAND "${GUNZIP}" ${COMPONENTS_CIF}.gz
+                WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/rsrc/)
 
-			add_custom_target(COMPONENTS ALL DEPENDS ${COMPONENTS_CIF})
-		endif()
+            add_custom_target(COMPONENTS ALL DEPENDS ${COMPONENTS_CIF})
+        endif()
 
-		# Do not continue if downloading went wrong
-		list(POP_FRONT CCD_FETCH_STATUS CCD_FETCH_STATUS_CODE)
+        # Do not continue if downloading went wrong
+        list(POP_FRONT CCD_FETCH_STATUS CCD_FETCH_STATUS_CODE)
 
-		if(CCD_FETCH_STATUS_CODE)
-			message(
-				FATAL_ERROR "cifpp: Error trying to download CCD file: ${CCD_FETCH_STATUS}")
-		endif()
-	endif()
+        if(CCD_FETCH_STATUS_CODE)
+            message(
+                FATAL_ERROR "cifpp: Error trying to download CCD file: ${CCD_FETCH_STATUS}")
+        endif()
+    endif()
 endif()
 
 # Installation directories
 if(BUILD_FOR_CCP4)
-	set(CIFPP_DATA_DIR
-		"$ENV{CCP4}/share/libcifpp"
-		CACHE PATH "Directory where dictionary and other static data is stored")
+    set(CIFPP_DATA_DIR
+        "$ENV{CCP4}/share/libcifpp"
+        CACHE PATH "Directory where dictionary and other static data is stored")
 else()
-	set(CIFPP_DATA_DIR
-		"${CMAKE_INSTALL_FULL_DATADIR}/libcifpp"
-		CACHE PATH "Directory where dictionary and other static data is stored")
+    set(CIFPP_DATA_DIR
+        "${CMAKE_INSTALL_FULL_DATADIR}/libcifpp"
+        CACHE PATH "Directory where dictionary and other static data is stored")
 endif()
 
 if(CIFPP_DATA_DIR)
-	target_compile_definitions(cifpp PUBLIC DATA_DIR="${CIFPP_DATA_DIR}")
-	set_target_properties(cifpp PROPERTIES CIFPP_DATA_DIR ${CIFPP_DATA_DIR})
+    target_compile_definitions(cifpp PUBLIC DATA_DIR="${CIFPP_DATA_DIR}")
+    set_target_properties(cifpp PROPERTIES CIFPP_DATA_DIR ${CIFPP_DATA_DIR})
 endif()
 
 if(NOT PROJECT_IS_TOP_LEVEL)
-	set(CIFPP_SHARE_DIR ${CIFPP_DATA_DIR} PARENT_SCOPE)
+    set(CIFPP_SHARE_DIR ${CIFPP_DATA_DIR} PARENT_SCOPE)
 endif()
 
 if(UNIX AND NOT BUILD_FOR_CCP4)
-	if("${CMAKE_INSTALL_PREFIX}" STREQUAL "/usr/local")
-		set(CIFPP_CACHE_DIR
-			"/var/cache/libcifpp"
-			CACHE PATH "The directory where downloaded data files are stored")
-	else()
-		set(CIFPP_CACHE_DIR
-			"${CMAKE_INSTALL_FULL_LOCALSTATEDIR}/cache/libcifpp"
-			CACHE PATH "The directory where downloaded data files are stored")
-	endif()
+    if("${CMAKE_INSTALL_PREFIX}" STREQUAL "/usr/local")
+        set(CIFPP_CACHE_DIR
+            "/var/cache/libcifpp"
+            CACHE PATH "The directory where downloaded data files are stored")
+    else()
+        set(CIFPP_CACHE_DIR
+            "${CMAKE_INSTALL_FULL_LOCALSTATEDIR}/cache/libcifpp"
+            CACHE PATH "The directory where downloaded data files are stored")
+    endif()
 
-	target_compile_definitions(cifpp PUBLIC CACHE_DIR="${CIFPP_CACHE_DIR}")
+    target_compile_definitions(cifpp PUBLIC CACHE_DIR="${CIFPP_CACHE_DIR}")
 
-	set(CIFPP_ETC_DIR
-		"${CMAKE_INSTALL_FULL_SYSCONFDIR}"
-		CACHE PATH "The directory where the update configuration file is stored")
+    set(CIFPP_ETC_DIR
+        "${CMAKE_INSTALL_FULL_SYSCONFDIR}"
+        CACHE PATH "The directory where the update configuration file is stored")
 else()
-	unset(CIFPP_CACHE_DIR)
+    unset(CIFPP_CACHE_DIR)
 endif()
 
 # Install rules
 install(TARGETS cifpp
-	EXPORT cifpp
-	FILE_SET cifpp_headers DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+    EXPORT cifpp
+    FILE_SET cifpp_headers DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 
 if(MSVC AND BUILD_SHARED_LIBS)
-	install(
-		FILES $<TARGET_PDB_FILE:cifpp>
-		DESTINATION ${CMAKE_INSTALL_LIBDIR}
-		OPTIONAL)
+    install(
+        FILES $<TARGET_PDB_FILE:cifpp>
+        DESTINATION ${CMAKE_INSTALL_LIBDIR}
+        OPTIONAL)
 endif()
 
 # Clean up old config files (with old names)
 file(GLOB OLD_CONFIG_FILES
-	${CMAKE_INSTALL_FULL_LIBDIR}/cmake/cifpp/cifppConfig*.cmake
-	${CMAKE_INSTALL_FULL_LIBDIR}/cmake/cifpp/cifppTargets*.cmake)
+    ${CMAKE_INSTALL_FULL_LIBDIR}/cmake/cifpp/cifppConfig*.cmake
+    ${CMAKE_INSTALL_FULL_LIBDIR}/cmake/cifpp/cifppTargets*.cmake)
 
 if(OLD_CONFIG_FILES)
-	message(
-		STATUS "cifpp: Installation will remove old config files: ${OLD_CONFIG_FILES}")
-	install(CODE "file(REMOVE ${OLD_CONFIG_FILES})")
+    message(
+        STATUS "cifpp: Installation will remove old config files: ${OLD_CONFIG_FILES}")
+    install(CODE "file(REMOVE ${OLD_CONFIG_FILES})")
 endif()
 
 install(EXPORT cifpp
-	NAMESPACE cifpp::
-	FILE "cifpp-targets.cmake"
-	DESTINATION lib/cmake/cifpp)
+    NAMESPACE cifpp::
+    FILE "cifpp-targets.cmake"
+    DESTINATION lib/cmake/cifpp)
 
 install(
-	FILES ${CMAKE_CURRENT_SOURCE_DIR}/rsrc/mmcif_ddl.dic
-	${CMAKE_CURRENT_SOURCE_DIR}/rsrc/mmcif_pdbx.dic
-	${CMAKE_CURRENT_SOURCE_DIR}/rsrc/mmcif_ma.dic
-	DESTINATION ${CMAKE_INSTALL_DATADIR}/libcifpp)
+    FILES ${CMAKE_CURRENT_SOURCE_DIR}/rsrc/mmcif_ddl.dic
+    ${CMAKE_CURRENT_SOURCE_DIR}/rsrc/mmcif_pdbx.dic
+    ${CMAKE_CURRENT_SOURCE_DIR}/rsrc/mmcif_ma.dic
+    DESTINATION ${CMAKE_INSTALL_DATADIR}/libcifpp)
 
 if(CIFPP_DATA_DIR AND CIFPP_DOWNLOAD_CCD)
-	install(FILES ${COMPONENTS_CIF}
-		DESTINATION ${CMAKE_INSTALL_DATADIR}/libcifpp)
+    install(FILES ${COMPONENTS_CIF}
+        DESTINATION ${CMAKE_INSTALL_DATADIR}/libcifpp)
 endif()
 
 set(CONFIG_TEMPLATE_FILE ${CMAKE_CURRENT_SOURCE_DIR}/cmake/cifpp-config.cmake.in)
 
 configure_package_config_file(
-	${CONFIG_TEMPLATE_FILE} ${CMAKE_CURRENT_BINARY_DIR}/cifpp/cifpp-config.cmake
-	INSTALL_DESTINATION lib/cmake/cifpp
-	PATH_VARS CIFPP_DATA_DIR)
+    ${CONFIG_TEMPLATE_FILE} ${CMAKE_CURRENT_BINARY_DIR}/cifpp/cifpp-config.cmake
+    INSTALL_DESTINATION lib/cmake/cifpp
+    PATH_VARS CIFPP_DATA_DIR)
 
 install(
-	FILES "${CMAKE_CURRENT_BINARY_DIR}/cifpp/cifpp-config.cmake"
-	"${CMAKE_CURRENT_BINARY_DIR}/cifpp/cifpp-config-version.cmake"
-	DESTINATION lib/cmake/cifpp)
+    FILES "${CMAKE_CURRENT_BINARY_DIR}/cifpp/cifpp-config.cmake"
+    "${CMAKE_CURRENT_BINARY_DIR}/cifpp/cifpp-config-version.cmake"
+    DESTINATION lib/cmake/cifpp)
 
 set_target_properties(
-	cifpp
-	PROPERTIES VERSION ${PROJECT_VERSION}
-	SOVERSION "${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}"
-	INTERFACE_cifpp_MAJOR_VERSION ${PROJECT_VERSION_MAJOR})
+    cifpp
+    PROPERTIES VERSION ${PROJECT_VERSION}
+    SOVERSION "${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}"
+    INTERFACE_cifpp_MAJOR_VERSION ${PROJECT_VERSION_MAJOR})
 
 set_property(
-	TARGET cifpp
-	APPEND
-	PROPERTY COMPATIBLE_INTERFACE_STRING cifpp_MAJOR_VERSION)
+    TARGET cifpp
+    APPEND
+    PROPERTY COMPATIBLE_INTERFACE_STRING cifpp_MAJOR_VERSION)
 
 write_basic_package_version_file(
-	"${CMAKE_CURRENT_BINARY_DIR}/cifpp/cifpp-config-version.cmake"
-	VERSION ${PROJECT_VERSION}
-	COMPATIBILITY AnyNewerVersion)
+    "${CMAKE_CURRENT_BINARY_DIR}/cifpp/cifpp-config-version.cmake"
+    VERSION ${PROJECT_VERSION}
+    COMPATIBILITY AnyNewerVersion)
 
 if(BUILD_TESTING AND PROJECT_IS_TOP_LEVEL)
-	add_subdirectory(test)
+    add_subdirectory(test)
 endif()
 
 # Optionally install the update scripts for CCD and dictionary files
 if(CIFPP_INSTALL_UPDATE_SCRIPT)
-	configure_file(${CMAKE_CURRENT_SOURCE_DIR}/tools/update-libcifpp-data.in
-		update-libcifpp-data @ONLY)
+    configure_file(${CMAKE_CURRENT_SOURCE_DIR}/tools/update-libcifpp-data.in
+        update-libcifpp-data @ONLY)
 
-	if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux" OR
-		${CMAKE_SYSTEM_NAME} STREQUAL "GNU" OR
-		${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD")
-		install(
-			FILES ${CMAKE_CURRENT_BINARY_DIR}/update-libcifpp-data
-			DESTINATION ${CMAKE_INSTALL_SYSCONFDIR}/cron.weekly
-			PERMISSIONS OWNER_EXECUTE OWNER_READ GROUP_EXECUTE GROUP_READ WORLD_EXECUTE
-			WORLD_READ)
-	else()
-		message(FATAL_ERROR "cifpp: Don't know where to install the update script")
-	endif()
+    if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux" OR
+        ${CMAKE_SYSTEM_NAME} STREQUAL "GNU" OR
+        ${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD")
+        install(
+            FILES ${CMAKE_CURRENT_BINARY_DIR}/update-libcifpp-data
+            DESTINATION ${CMAKE_INSTALL_SYSCONFDIR}/cron.weekly
+            PERMISSIONS OWNER_EXECUTE OWNER_READ GROUP_EXECUTE GROUP_READ WORLD_EXECUTE
+            WORLD_READ)
+    else()
+        message(FATAL_ERROR "cifpp: Don't know where to install the update script")
+    endif()
 
-	# a config file, to make it complete
-	# install(DIRECTORY DESTINATION "${CMAKE_INSTALL_LOCALSTATEDIR}/libcifpp")
-	if(NOT EXISTS "${CMAKE_INSTALL_SYSCONFDIR}/libcifpp.conf")
-		file(
-			WRITE ${CMAKE_CURRENT_BINARY_DIR}/libcifpp.conf
-			[[# Uncomment the next line to enable automatic updates
+    # a config file, to make it complete
+    # install(DIRECTORY DESTINATION "${CMAKE_INSTALL_LOCALSTATEDIR}/libcifpp")
+    if(NOT EXISTS "${CMAKE_INSTALL_SYSCONFDIR}/libcifpp.conf")
+        file(
+            WRITE ${CMAKE_CURRENT_BINARY_DIR}/libcifpp.conf
+            [[# Uncomment the next line to enable automatic updates
 # update=true
 ]])
-		install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libcifpp.conf
-			DESTINATION ${CMAKE_INSTALL_SYSCONFDIR})
-		install(
-			CODE "message(\"cifpp: A configuration file has been written to ${CIFPP_ETC_DIR}/libcifpp.conf, please edit this file to enable automatic updates\")"
-		)
+        install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libcifpp.conf
+            DESTINATION ${CMAKE_INSTALL_SYSCONFDIR})
+        install(
+            CODE "message(\"cifpp: A configuration file has been written to ${CIFPP_ETC_DIR}/libcifpp.conf, please edit this file to enable automatic updates\")"
+        )
 
-		install(DIRECTORY DESTINATION ${CMAKE_INSTALL_SYSCONFDIR}/libcifpp/cache-update.d)
-	endif()
+        install(DIRECTORY DESTINATION ${CMAKE_INSTALL_SYSCONFDIR}/libcifpp/cache-update.d)
+    endif()
 
-	target_compile_definitions(cifpp PUBLIC CACHE_DIR="${CIFPP_CACHE_DIR}")
+    target_compile_definitions(cifpp PUBLIC CACHE_DIR="${CIFPP_CACHE_DIR}")
 endif()
 
 if(BUILD_DOCUMENTATION)
-	add_subdirectory(docs)
+    add_subdirectory(docs)
+endif()
+
+if(BUILD_EXAMPLES)
+    add_subdirectory(examples)
 endif()

README.md

@@ -38,9 +38,7 @@ The documentation can be found at [github.io](https://pdb-redo.github.io/libcifp
 #include <filesystem>
 #include <iostream>
 
-#include <cif++.hpp>
-
-namespace fs = std::filesystem;
+#include <cif++/cif++.hpp>
 
 int main(int argc, char *argv[])
 {

changelog

@@ -1,3 +1,57 @@
+Version 10.0.4
+- Fixed find_by_value in the index of a category,
+  avoid swapping columns in the search keys
+
+Version 10.0.3
+- Clear pdbx_nonpoly_scheme before filling it in reconstruction
+- Changed handling of numbers with a preceding plus character,
+  these are now stored as strings to avoid inadvertently
+  mutilating phone numbers.
+
+Version 10.0.2
+- Fixed regression in reconstruction introduced in 10.0.1
+- Fixed symmetry operations
+- Added validation for pdbx_item_enumeration as well as
+  case-sensitive checks for enumerations when needed.
+
+Version 10.0.1
+- Fixed some regressions, like assigning to items.
+- At emplace time (in category) values that are
+  in the wrong type according to a dictionary
+  will be converted/casted. May fail of course.
+
+Version 10.0.0
+- Major rewrite of the internal storage of values.
+  Used to be strings only, now there are several
+  basic types.
+- Modernised code and cleaned up warnings using lint
+  tools
+
+Version 9.0.6
+- Various small fixes
+Version 10.0.0
+- Added a SQLite interface.
+
+Version 9.0.5
+- Added exists to compound_factory
+- Added sub_matrix, fix and extend determinant calculation
+- Added yet another structure::create_non_poly
+- Remove revision.hpp file in make clean (new VersionString.cmake)
+
+Version 9.0.4
+- Fix various stopping and reconstruction errors
+
+Version 9.0.3
+- Reconstruction fixed when some entity ids are missing
+
+Version 9.0.2
+- Fix code that reconstructs sequences, could throw a map::at
+- Many optimisations in validation and reconstruction code.
+
+Version 9.0.1
+- Use pcre2 from pkg-config if available, if not
+  build a version from the original code.
+
 Version 9.0.0
 - Rename fields of cif::mm::polymer to match the naming
   in mmcif_pdbx.dic. Also, related, fix building mm::structure

cmake/FindAtomic.cmake

@@ -1,3 +1,27 @@
+# SPDX-License-Identifier: BSD-2-Clause
+# 
+# Copyright (c) 2026 NKI/AVL, Netherlands Cancer Institute
+# 
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+# 
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
 # Simple check to see if we need a library for std::atomic
 
 if(TARGET std::atomic)

cmake/FindPCRE2.cmake

@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: BSD-2-Clause
+# 
+# Copyright (c) 2026 NKI/AVL, Netherlands Cancer Institute
+# 
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+# 
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# 
+# The problem is, find_package(PCRE2) does not work
+# and using pkg-config results in linking to a shared library
+# causing all kinds of trouble later on
+
+find_path(PCRE2_INCLUDEDIR NAMES pcre2.h HINTS "C:/Program Files (x86)/PCRE2/include" REQUIRED)
+find_library(PCRE2_LIBRARY NAMES pcre2-8-static libpcre2-8.a HINTS "C:/Program Files (x86)/PCRE2/lib" REQUIRED)
+
+add_library(pcre2-8 IMPORTED STATIC)
+target_include_directories(pcre2-8 INTERFACE ${PCRE2_INCLUDEDIR})
+target_compile_definitions(pcre2-8 INTERFACE PCRE2_STATIC)
+set_target_properties(pcre2-8 PROPERTIES IMPORTED_LOCATION ${PCRE2_LIBRARY})
+set_target_properties(pcre2-8 PROPERTIES IMPORTED_IMPLIB ${PCRE2_LIBRARY})

cmake/FindPCRE2x.cmake

@@ -1,33 +0,0 @@
-set(PCRE2_USE_STATIC_LIBS ON)
-
-find_package(pcre2 CONFIG)
-
-if(PCRE2_FOUND)
-	message(STATUS "Using pcre2 found using find_package")
-else()
-	include(FindPkgConfig)
-
-	if(PKG_CONFIG_FOUND)
-		pkg_check_modules(PCRE2 IMPORTED_TARGET libpcre2-8)
-
-		if(PCRE2_FOUND)
-			message(STATUS "Using pcre2 found using pkg-config")
-
-			add_library(pcre2-8 ALIAS PkgConfig::PCRE2)
-		endif()
-	endif()
-endif()
-
-if(NOT PCRE2_FOUND)
-	message(STATUS "Using pcre2 using FetchContent")
-
-	set(PCRE2_BUILD_TESTS OFF)
-	FetchContent_Declare(
-		pcre2
-		GIT_REPOSITORY https://github.com/PCRE2Project/pcre2
-		GIT_TAG pcre2-10.45
-		EXCLUDE_FROM_ALL)
-	FetchContent_MakeAvailable(pcre2)
-
-	# add_subdirectory(${pcre2_SOURCE_DIR} EXCLUDE_FROM_ALL)
-endif()

cmake/FindSphinx.cmake

@@ -1,4 +1,29 @@
+# SPDX-License-Identifier: BSD-2-Clause
+# 
+# Copyright (c) 2026 NKI/AVL, Netherlands Cancer Institute
+# 
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+# 
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
 #Look for an executable called sphinx-build
+
 find_program(SPHINX_EXECUTABLE
              NAMES sphinx-build
              DOC "Path to sphinx-build executable")

cmake/VersionString.cmake

@@ -238,7 +238,7 @@ function(write_version_header dir)
 		if(res EQUAL 0)
 			set(REVISION_STRING "${out}")
 		else()
-			message(STATUS "Git hash not found, does this project has a 'build' tag?")
+			message(STATUS "Git hash not found, does this project have a 'build' tag?")
 		endif()
 	else()
 		message(STATUS "Git hash not found")

cmake/cifpp-config.cmake.in

@@ -8,5 +8,6 @@ include(CMakeFindDependencyMacro)
 
 find_dependency(Threads)
 find_dependency(ZLIB REQUIRED)
+find_dependency(SQLite3 REQUIRED)
 
 check_required_components(cifpp)

cmake/revision.hpp.in

@@ -36,7 +36,8 @@ class version_info_base
 	}
 
   protected:
-	version_info_base(const char *name, const char *version, int build_number, const char *git_tag, const char *revision_date, bool is_main)
+	version_info_base(const char *name, const char *version, int build_number,
+			const char *git_tag, const char *revision_date, bool is_main) noexcept
 		: m_name(name)
 		, m_version(version)
 		, m_build_number(build_number)
@@ -70,13 +71,13 @@ class version_info_base
 
 	using version_info_ptr = version_info_base *;
 
-	static version_info_ptr &registered_main()
+	static version_info_ptr &registered_main() noexcept
 	{
 		static version_info_ptr s_main = nullptr;
 		return s_main;
 	}
 
-	static version_info_ptr &registered_libraries()
+	static version_info_ptr &registered_libraries() noexcept
 	{
 		static version_info_ptr s_head = nullptr;
 		return s_head;
@@ -96,7 +97,9 @@ class version_info : public version_info_base
   public:
 	using implementation_type = T;
 
-	version_info(const char *name, const char *version, int build_number, const char *git_tag, const char *revision_date, bool is_main)
+	// NOLINTNEXTLINE
+	version_info(const char *name, const char *version, int build_number,
+			const char *git_tag, const char *revision_date, bool is_main) noexcept
 		: version_info_base(name, version, build_number, git_tag, revision_date, is_main)
 	{
 	}
@@ -114,8 +117,9 @@ inline void write_version_string(std::ostream &os, bool verbose)
 const class version_info_@IDENT_PREFIX@impl : public version_info_v1_1::version_info<version_info_@IDENT_PREFIX@impl>
 {
   public:
-	version_info_@IDENT_PREFIX@impl()
-		: version_info(k@VAR_PREFIX@ProjectName, k@VAR_PREFIX@VersionNumber, k@VAR_PREFIX@BuildNumber, k@VAR_PREFIX@RevisionGitTag, k@VAR_PREFIX@RevisionDate, @BOOL_IS_MAIN@)
+	version_info_@IDENT_PREFIX@impl() noexcept
+		: version_info(k@VAR_PREFIX@ProjectName, k@VAR_PREFIX@VersionNumber,
+			k@VAR_PREFIX@BuildNumber, k@VAR_PREFIX@RevisionGitTag, k@VAR_PREFIX@RevisionDate, @BOOL_IS_MAIN@)
 	{
 	}
 } s_version_info_@IDENT_PREFIX@instance;

cmake/test-charconv.cpp

@@ -1,7 +1,7 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause
  * 
- * Copyright (c) 2022 NKI/AVL, Netherlands Cancer Institute
+ * Copyright (c) 2026 NKI/AVL, Netherlands Cancer Institute
  * 
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -24,9 +24,20 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#pragma once
+#include <charconv>
+#include <cassert>
+#include <cstring>
 
-/// \file io.hpp
-/// \deprecated This file is no longer used. Please use "cif++/pdb.hpp" instead
+int main()
+{
+	float v;
+	char s[] = "1.0";
 
-#warning "Use of this file is deprecated, please use "cif++/pdb.hpp"
+	auto r = std::from_chars(s, s + strlen(s), v);
+
+	assert(r.ec == std::errc{});
+	assert(r.ptr = s + strlen(s));
+	assert(v == 1.0f);
+
+	return 0;
+}

docs/CMakeLists.txt

@@ -1,3 +1,27 @@
+# SPDX-License-Identifier: BSD-2-Clause
+# 
+# Copyright (c) 2026 NKI/AVL, Netherlands Cancer Institute
+# 
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+# 
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
 find_package(Doxygen REQUIRED)
 find_package(Sphinx REQUIRED)
 
@@ -16,33 +40,35 @@ set(DOXYFILE_OUT ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile)
 configure_file(${DOXYFILE_IN} ${DOXYFILE_OUT} @ONLY)
 
 add_custom_command(
-	OUTPUT ${DOXYGEN_OUTPUT_DIR}
-	COMMAND ${CMAKE_COMMAND} -E make_directory ${DOXYGEN_OUTPUT_DIR})
+    OUTPUT ${DOXYGEN_OUTPUT_DIR}
+    COMMAND ${CMAKE_COMMAND} -E make_directory ${DOXYGEN_OUTPUT_DIR})
 
 add_custom_command(OUTPUT ${DOXYGEN_INDEX_FILE}
-	BYPRODUCTS ${DOXYGEN_OUTPUT_DIR}
-	DEPENDS ${DOXYGEN_OUTPUT_DIR} ${CIFPP_PUBLIC_HEADERS} ${DOXYFILE_OUT}
-	COMMAND ${DOXYGEN_EXECUTABLE} ${DOXYFILE_OUT}
-	MAIN_DEPENDENCY ${DOXYFILE_OUT} ${DOXYFILE_IN}
-	COMMENT "Generating docs")
-
-add_custom_target("Doxygen-${PROJECT_NAME}" ALL DEPENDS ${DOXYGEN_INDEX_FILE})
+    DEPENDS ${CIFPP_PUBLIC_HEADERS} ${DOXYGEN_OUTPUT_DIR} ${DOXYFILE_OUT}
+    COMMAND ${DOXYGEN_EXECUTABLE} ${DOXYFILE_OUT}
+    MAIN_DEPENDENCY ${DOXYFILE_OUT} ${DOXYFILE_IN}
+    COMMENT "Generating docs")
 
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/conf.py.in ${CMAKE_CURRENT_SOURCE_DIR}/conf.py @ONLY)
 
 set(SPHINX_SOURCE ${CMAKE_CURRENT_SOURCE_DIR})
 set(SPHINX_BUILD ${CMAKE_CURRENT_BINARY_DIR}/sphinx)
 
-add_custom_target("Sphinx-${PROJECT_NAME}" ALL
-	COMMAND ${SPHINX_EXECUTABLE} -b html
-	-Dbreathe_projects.${PROJECT_NAME}=${DOXYGEN_OUTPUT_DIR}
-	${SPHINX_SOURCE} ${SPHINX_BUILD}
-	DEPENDS ${DOXYGEN_INDEX_FILE}
-	BYPRODUCTS ${CMAKE_CURRENT_SOURCE_DIR}/api
-	WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-	COMMENT "Generating documentation with Sphinx")
+add_custom_target("Sphinx-cifpp" ALL
+    COMMAND ${SPHINX_EXECUTABLE} -b html
+    -Dbreathe_projects.cifpp=${DOXYGEN_OUTPUT_DIR}
+    ${SPHINX_SOURCE} ${SPHINX_BUILD}
+    DEPENDS ${DOXYGEN_INDEX_FILE}
+    BYPRODUCTS ${CMAKE_CURRENT_SOURCE_DIR}/api
+    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+    COMMENT "Generating documentation with Sphinx")
 
-install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/sphinx/
-	DESTINATION ${CMAKE_INSTALL_DOCDIR}
-	PATTERN .doctrees EXCLUDE
-	PATTERN .buildinfo EXCLUDE)
+set_property(TARGET Sphinx-cifpp APPEND PROPERTY ADDITIONAL_CLEAN_FILES
+    ${DOXYGEN_OUTPUT_DIR}
+    ${CMAKE_CURRENT_SOURCE_DIR}/api)
+
+install(
+    DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/sphinx/
+    DESTINATION ${CMAKE_INSTALL_DOCDIR}
+    PATTERN .doctrees EXCLUDE
+    PATTERN .buildinfo EXCLUDE)

docs/Doxyfile.in

@@ -1,10 +1,67 @@
-EXCLUDE_SYMBOLS        = cif::detail::*, std*
+# EXCLUDE_SYMBOLS        = cif::detail::*, std*
 FILE_PATTERNS          = *.hpp
 STRIP_FROM_PATH        = @DOXYGEN_INPUT_DIR@
 RECURSIVE              = YES
 GENERATE_XML           = YES
 GENERATE_LATEX         = NO
+MACRO_EXPANSION = YES
 PREDEFINED             += and=&& or=|| not=! CIFPP_EXPORT= HAVE_LIBCLIPPER=1
 GENERATE_HTML          = NO
 GENERATE_TODOLIST      = NO
 INPUT                  = @DOXYGEN_INPUT_DIR@
+
+
+# # Doxyfile
+
+# PROJECT_NAME = "libcifpp"
+# PROJECT_BRIEF = "C++ library for using mmCIF files"
+
+# GENERATE_LATEX = NO
+
+# EXTRACT_ALL = YES
+# EXTRACT_STATIC = YES
+# HIDE_UNDOC_CLASSES = NO
+# SHOW_NAMESPACES = YES
+# EXTRACT_TEMPLATE_PARAMS = YES
+
+# CREATE_SUBDIRS = NO
+# INLINE_GROPUED_CLASSES = YES
+# INLINE_SIMPLE_STRUCTS = YES
+
+# NUM_PROC_THREADS = 0
+
+# EXTRACT_LOCAL_CLASSES = NO
+# HIDE_IN_BODY_DOCS = YES
+
+# SHOW_HEADERFILE = NO
+
+# INPUT = @DOXYGEN_INPUT_DIR@/c++
+# RECURSIVE = YES
+# EXAMPLE_PATH = @DOXYGEN_INPUT_DIR@/../examples
+
+# EXAMPLE_PATTERNS = *.cpp
+
+# # USE_MDFILE_AS_MAINPAGE = ../README.md
+
+# ENABLE_PREPROCESSING = YES
+# MACRO_EXPANSION = YES
+# INCLUDE_PATH = @DOXYGEN_INPUT_DIR@
+# INCLUDE_FILE_PATTERNS = *.hpp
+
+# SKIP_FUNCTION_MACROS = NO
+
+# # CLANG_ASSISTED_PARSING = YES
+# # CLANG_ADD_INC_PATHS = YES
+# # CLANG_OPTIONS = -O0 -std=c++23
+
+# # GENERATE_HTML = YES
+# # GENERATE_TREEVIEW = YES
+
+# GENERATE_XML = YES
+
+# # EXCLUDE_SYMBOLS = cif::detail::*, std*
+# # # FILE_PATTERNS = *.hpp
+# # STRIP_FROM_PATH = @DOXYGEN_INPUT_DIR@
+# # PREDEFINED             += and=&& or=|| not=! CIFPP_EXPORT= HAVE_LIBCLIPPER=1
+# # GENERATE_HTML = NO
+# # GENERATE_TODOLIST = NO

docs/basics.rst

@@ -7,7 +7,7 @@ Reading a file is as simple as:
 
 .. code-block:: cpp
 
-    #include <cif++.hpp>
+    #include <cif++/cif++.hpp>
 
     cif::file f("/path/to/file.cif");
 
@@ -76,7 +76,7 @@ Categories contain rows of data and each row has fields or items. Referencing a
     auto rh = atom_site.front();
 
     // Get the label_atom_id value from this row handle as a std::string
-    std::string atom_id = rh["label_atom_id"].as<std::string>();
+    std::string atom_id = rh["label_atom_id"].get<std::string>();
 
     // Get the x, y and z coordinates using structered binding
     const auto &[x, y, z] = rh.get<float,float,float>("Cartn_x", "Cartn_y", "Cartn_z");
@@ -214,7 +214,7 @@ A simple case:
 
 .. code-block:: cpp
 
-    #include <cif++.hpp>
+    #include <cif++/cif++.hpp>
 
     cif::file f("1cbs.cif.gz");
     f.load_dictionary("mmcif_pdbx.dic");

docs/conf.py.in

@@ -1,5 +1,7 @@
+# Configuration file 
+
 project = '@PROJECT_NAME@'
-copyright = '2023, Maarten L. Hekkelman'
+copyright = '2026, Maarten L. Hekkelman'
 author = 'Maarten L. Hekkelman'
 release = '@PROJECT_VERSION@'
 
@@ -12,7 +14,7 @@ extensions = [
 ]
 
 breathe_projects = {
-	"@PROJECT_NAME@": "../build/docs/xml"
+	"@PROJECT_NAME@": "@DOXYGEN_OUTPUT_DIR@"
 }
 
 myst_enable_extensions = [ "colon_fence" ]
@@ -60,7 +62,7 @@ html_static_path = ['_static']
 html_theme_options = {
 }
 
-cpp_index_common_prefix = [
-	'cif::'
-]
+# cpp_index_common_prefix = [
+# 	'cif::'
+# ]
 

docs/cql.rst

@@ -0,0 +1,33 @@
+CQL
+===
+
+The structure of cif files (even of STAR files, from which this format is derived) looks suspiciously like a relational database. When you consider categories to be tables and items to be columns you're almost there. The only problem is linking tables, in common cif files this is done based on multiple columns and the rules are a bit fuzzy allowing for empty columns to still match related columns that do have a value.
+
+An early version of the tool *mmCQL* contained a SQL like language interpreter to SELECT and UPDATE values in cif files. This functionality has been expanded by implementing a full SQL interface using the `SQLite <https://sqlite.org>`_ library. Libcifpp categories are exposed as virtual tables in a SQLite environment and can be queried and manipulated using SQL syntax.
+
+The current limitation is that CREATE TABLE and ALTER TABLE are not supported yet. Since SQLite has no way of supporting this, we will have to write a preprocessor to intercept these statements. That's on the to-do list.
+
+The new *mmcql* tools in `cif-tools <https://github.com/PDB-REDO/cif-tools>`_ uses this new backend and is a command line application you can use similar to the *sqlite* or e.g. *psql* tools for regular SQLite files and postgresql databanks respectively.
+
+Synopsis
+--------
+
+.. literalinclude:: ../examples/example-cql.cpp
+	:language: c++
+	:start-at: #include <cif++/cif++.hpp>
+
+Usage
+-----
+
+To start using CQL, you will first have to create a :cpp:class:`connection` to a :cpp:class:`cif::cql::datablock`. Using this connection you can create a :cpp:class:`transaction`. And with the transaction can execute SQL statements using :cpp:func:`cif::cql::transaction::exec`. Or you can use the :cpp:func:`cif::cql::transaction::stream` function to directly pull values from the result.
+
+The result of :cpp:func:`cif::cql::transaction::exec` is a :cpp:class:`cif::cql::result` class which uses a :cpp:class:`cif::category` as storage class.
+
+Implementation Details
+----------------------
+
+When the datablock contains a validator (i.e. you loaded a dictionary) the SQL engine knows about all possible items/columns that are allowed. It also knows about links/relations between categories, just like the regular libcifpp query mechanism. So, updating and deleting will cascade automatically.
+
+Another point is data types. cif files can have numbers, strings or NULL values. Same goes for SQLite. However, when a file was loaded without a dictionary, the type of an item is dependent on its content. If something was parsed as being a number, the type will be numeric. If however, the file does contain a dictionary/validator, the type is determined by this dictionary. So, even if it looks like a number, it still might be a string internally. Good example is the ID field in atom_site, or the auth_seq_id/auth_seq_num fields. In the WHERE clause this may have unexpected results, so you may have to fall back to using `CAST <https://sqlite.org/lang_expr.html#castexpr>`_.
+
+The API for this functionality is a bit new, there may be room for improvement. Ideas are welcome.

docs/index.rst

@@ -38,6 +38,7 @@ Using *libcifpp* is easy, if you are familiar with modern C++:
    basics.rst
    compound.rst
    model.rst
+   cql.rst
    resources.rst
    symmetry.rst
    bitsandpieces.rst

examples/CMakeLists.txt

@@ -1,7 +1,36 @@
+# SPDX-License-Identifier: BSD-2-Clause
+# 
+# Copyright (c) 2026 NKI/AVL, Netherlands Cancer Institute
+# 
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+# 
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
 cmake_minimum_required(VERSION 3.15)
 project(cifpp_example LANGUAGES CXX)
 
-find_package(cifpp REQUIRED)
+if(PROJECT_IS_TOP_LEVEL AND NOT (TARGET cifpp OR cifpp_FOUND))
+    find_package(cifpp REQUIRED)
+endif()
 
 add_executable(example example.cpp)
-target_link_libraries(example cifpp::cifpp)
+target_link_libraries(example cifpp::cifpp)
+
+add_executable(example-cql example-cql.cpp)
+target_link_libraries(example-cql cifpp::cifpp)

examples/example-cql.cpp

@@ -1,17 +1,17 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause
- *
- * Copyright (c) 2020 NKI/AVL, Netherlands Cancer Institute
- *
+ * 
+ * Copyright (c) 2026 NKI/AVL, Netherlands Cancer Institute
+ * 
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
- *
+ * 
  * 1. Redistributions of source code must retain the above copyright notice, this
  *    list of conditions and the following disclaimer
  * 2. Redistributions in binary form must reproduce the above copyright notice,
  *    this list of conditions and the following disclaimer in the documentation
  *    and/or other materials provided with the distribution.
- *
+ * 
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
@@ -23,31 +23,42 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
+ 
+#include <cif++/cif++.hpp>
+#include <filesystem>
+#include <iostream>
 
-#pragma once
-
-#include <string>
-#include <vector>
-
-/**
- * @file forward_decl.hpp
- * 
- * File containing only forward declarations
- * 
- */
-
-namespace cif
+int main(int argc, char *argv[])
 {
+	if (argc != 2)
+	{
+		std::cerr << "Usage: example <inputfile>\n";
+		exit(1);
+	}
 
-class category;
-class datablock;
-class file;
-class parser;
+	cif::file file(argv[1]);
 
-class row;
-class row_handle;
+	if (file.empty())
+	{
+		std::cerr << "Empty file\n";
+		exit(1);
+	}
 
-class item;
-struct item_handle;
+	auto &db = file.front();
+	cif::cql::connection c(db);
+	cif::cql::transaction tx(c);
 
-} // namespace cif
+	auto N = tx.exec("SELECT COUNT(*) FROM atom_site").one_field().get<std::size_t>();
+	auto M = tx.exec("SELECT COUNT(*) FROM atom_site WHERE label_atom_id = 'OXT'").one_field().get<std::size_t>();
+
+	std::cout << "File contains " << N << " atoms of which " << M << (M == 1 ? " is" : " are") << " OXT\n"
+			  << "residues with an OXT are:\n";
+
+	for (const auto &[asym, comp, seqnr] : tx.stream<std::string, std::string, int>(
+			 "SELECT label_asym_id, label_comp_id, label_seq_id FROM atom_site WHERE label_atom_id = 'OXT'"))
+	{
+		std::cout << asym << ' ' << comp << ' ' << seqnr << '\n';
+	}
+
+	return 0;
+}

examples/example.cpp

@@ -1,9 +1,33 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ * 
+ * Copyright (c) 2026 NKI/AVL, Netherlands Cancer Institute
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
 #include <filesystem>
 #include <iostream>
 
-#include <cif++.hpp>
-
-namespace fs = std::filesystem;
+#include <cif++/cif++.hpp>
 
 int main(int argc, char *argv[])
 {

include/cif++.hpp

@@ -26,16 +26,8 @@
 
 #pragma once
 
-#include "cif++/utilities.hpp"
-#include "cif++/file.hpp"
-#include "cif++/parser.hpp"
-#include "cif++/format.hpp"
+#warning "Using this file is deprecated, use #include <cif++/cif++.hpp> instead"
 
-#include "cif++/compound.hpp"
-#include "cif++/point.hpp"
-#include "cif++/symmetry.hpp"
-
-#include "cif++/model.hpp"
-
-#include "cif++/pdb.hpp"
-#include "cif++/gzio.hpp"
+// IWYU pragma: begin_exports
+#include "cif++/cif++.hpp"
+// IWYU pragma: end_exports

include/cif++/atom_type.hpp

@@ -33,6 +33,7 @@
 
 #include "cif++/exports.hpp"
 
+#include <array>
 #include <cstdint>
 #include <limits>
 #include <stdexcept>
@@ -235,7 +236,7 @@ struct atom_type_info
 
 	/// Array containing all known radii for this element. A value of kNA is
 	/// stored for unknown values
-	float radii[kRadiusTypeCount];
+	std::array<float, kRadiusTypeCount> radii;
 };
 
 /// Array of atom_type_info struct for each of the defined elements in atom_type
@@ -256,12 +257,12 @@ class atom_type_traits
 	/// Constructor based on the element as a string in \a symbol
 	atom_type_traits(const std::string &symbol);
 
-	atom_type type() const { return m_info->type; }       ///< Returns the atom_type
-	std::string name() const { return m_info->name; }     ///< Returns the name of the element
-	std::string symbol() const { return m_info->symbol; } ///< Returns the symbol of the element
-	float weight() const { return m_info->weight; }       ///< Returns the average weight of the element
+	[[nodiscard]] atom_type type() const { return m_info->type; }       ///< Returns the atom_type
+	[[nodiscard]] std::string name() const { return m_info->name; }     ///< Returns the name of the element
+	[[nodiscard]] std::string symbol() const { return m_info->symbol; } ///< Returns the symbol of the element
+	[[nodiscard]] float weight() const { return m_info->weight; }       ///< Returns the average weight of the element
 
-	bool is_metal() const { return m_info->metal; } ///< Returns true if the element is a metal
+	[[nodiscard]] bool is_metal() const { return m_info->metal; } ///< Returns true if the element is a metal
 
 	/// Return true if the symbol in \a symbol actually exists in the list of known elements in atom_type
 	static bool is_element(const std::string &symbol);
@@ -272,7 +273,7 @@ class atom_type_traits
 	/// @brief Return the radius for the element, use \a type to select which radius to return
 	/// @param type The selector for which radius to return
 	/// @return The requested radius or kNA if not known (or applicable)
-	float radius(radius_type type = radius_type::single_bond) const
+	[[nodiscard]] float radius(radius_type type = radius_type::single_bond) const
 	{
 		if (type >= radius_type::type_count)
 			throw std::invalid_argument("invalid radius requested");
@@ -283,20 +284,20 @@ class atom_type_traits
 	///
 	/// \param charge  The charge of the ion
 	/// \return        The radius of the ion
-	float crystal_ionic_radius(int charge) const;
+	[[nodiscard]] float crystal_ionic_radius(int charge) const;
 
 	/// \brief Return the radius for a charged version of this atom in a non-solid environment
 	///
 	/// \param charge  The charge of the ion
 	/// \return        The radius of the ion
-	float effective_ionic_radius(int charge) const;
+	[[nodiscard]] float effective_ionic_radius(int charge) const;
 
 	/// \brief Return the radius for a charged version of this atom, returns the effective radius by default
 	///
 	/// \param charge  The charge of the ion
 	/// \param type    The requested ion radius type
 	/// \return        The radius of the ion
-	float ionic_radius(int charge, ionic_radius_type type = ionic_radius_type::effective) const
+	[[nodiscard]] float ionic_radius(int charge, ionic_radius_type type = ionic_radius_type::effective) const
 	{
 		return type == ionic_radius_type::effective ? effective_ionic_radius(charge) : crystal_ionic_radius(charge);
 	}
@@ -321,16 +322,16 @@ class atom_type_traits
 	///
 	/// @param charge The charge for which the structure values should be returned, use kWSKFVal to return the *Cval* and *Siva* values
 	/// @return The scattering factors as a SFData struct
-	const SFData &wksf(int charge = 0) const;
+	[[nodiscard]] const SFData &wksf(int charge = 0) const;
 
 	/// @brief Return the electron scattering factor values for the element
 	///
 	/// @return The scattering factors as a SFData struct
-	const SFData &elsf() const;
+	[[nodiscard]] const SFData &elsf() const;
 
 	/// Clipper doesn't like atoms with charges that do not have a scattering factor. And
 	/// rightly so, but we need to know in advance if this is the case
-	bool has_sf(int charge) const;
+	[[nodiscard]] bool has_sf(int charge) const;
 
   private:
 	const struct atom_type_info *m_info;

include/cif++/category.hpp

@@ -26,14 +26,31 @@
 
 #pragma once
 
-#include "cif++/forward_decl.hpp"
-
 #include "cif++/condition.hpp"
+#include "cif++/item.hpp"
 #include "cif++/iterator.hpp"
 #include "cif++/row.hpp"
 #include "cif++/text.hpp"
 
-#include <array>
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <functional>
+#include <iosfwd>
+#include <iterator>
+#include <limits>
+#include <memory>
+#include <optional>
+#include <ranges>
+#include <set>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+#include <vector>
 
 /** \file category.hpp
  * Documentation for the cif::category class
@@ -50,6 +67,7 @@
 namespace cif
 {
 
+class datablock;
 class validator;
 struct category_validator;
 struct item_validator;
@@ -82,13 +100,14 @@ class missing_key_error : public std::runtime_error
 	/**
 	 * @brief Construct a new duplicate key error object
 	 */
-	missing_key_error(const std::string &msg, const std::string &key)
+	missing_key_error(const std::string &msg, std::string key)
 		: std::runtime_error(msg)
-		, m_key(key)
+		, m_key(std::move(key))
 	{
 	}
 
-	const std::string &get_key() const noexcept { return m_key; }
+	/// Return the name of the key that was missing
+	[[nodiscard]] const std::string &get_key() const noexcept { return m_key; }
 
   private:
 	std::string m_key;
@@ -102,22 +121,12 @@ class multiple_results_error : public std::runtime_error
 	/**
 	 * @brief Construct a new multiple results error object
 	 */
-	multiple_results_error()
+	multiple_results_error() // NOLINT
 		: std::runtime_error("query should have returned exactly one row")
 	{
 	}
 };
 
-// --------------------------------------------------------------------
-// These should be moved elsewhere, one day.
-
-/// \cond
-template <typename _Tp>
-inline constexpr bool is_optional_v = false;
-template <typename _Tp>
-inline constexpr bool is_optional_v<std::optional<_Tp>> = true;
-/// \endcond
-
 // --------------------------------------------------------------------
 
 /// The class category is a sequence container for rows of data values.
@@ -134,14 +143,17 @@ class category
 
 	friend class row_handle;
 
-	template <typename, typename...>
-	friend class iterator_impl;
+	template <bool, typename...>
+	friend class iterator_impl_base;
 
 	using value_type = row_handle;
-	using reference = value_type;
-	using const_reference = const value_type;
-	using iterator = iterator_impl<category>;
-	using const_iterator = iterator_impl<const category>;
+	using reference = row_handle;
+	using const_reference = const_row_handle;
+	using iterator = iterator_impl<>;
+	using const_iterator = const_iterator_impl<>;
+
+	static_assert(std::input_iterator<iterator>);
+	static_assert(std::input_iterator<const_iterator>);
 
 	/// \endcond
 
@@ -164,7 +176,8 @@ class category
 		swap(*this, rhs);
 	}
 
-	category &operator=(category rhs) ///< assignement operator
+	/// Assignment operator
+	category &operator=(category rhs)
 	{
 		swap(*this, rhs);
 		return *this;
@@ -175,19 +188,41 @@ class category
 	/// you will not derive from this class.
 	~category();
 
+	/// Swap two categories
 	friend void swap(category &a, category &b) noexcept;
 
 	// --------------------------------------------------------------------
 
-	const std::string &name() const { return m_name; } ///< Returns the name of the category
+	[[nodiscard]] const std::string &name() const { return m_name; } ///< Returns the name of the category
 
-	[[deprecated("use key_items instead")]] iset key_fields() const; ///< Returns the cif::iset of key item names. Retrieved from the @ref category_validator for this category
+	/// \brief Rename category to @a new_name
+	void name(std::string_view new_name)
+	{
+		m_name = new_name;
+		m_dirty = true;
+	}
 
-	iset key_items() const; ///< Returns the cif::iset of key item names. Retrieved from the @ref category_validator for this category
+	/// \brief Return true if the category has been modified since last open/save
+	[[nodiscard]] constexpr bool is_dirty() const
+	{
+		return m_dirty;
+	}
 
-	[[deprecated("use key_item_indices instead")]] std::set<uint16_t> key_field_indices() const; ///< Returns a set of indices for the key items.
+	/// \brief Mark the category as modified according to @a dirty
+	void set_dirty(bool dirty)
+	{
+		m_dirty = dirty;
+	}
 
-	std::set<uint16_t> key_item_indices() const; ///< Returns a set of indices for the key items.
+	// --------------------------------------------------------------------
+
+	[[deprecated("use key_items instead")]] [[nodiscard]] iset key_fields() const; ///< Returns the cif::iset of key item names. Retrieved from the @ref category_validator for this category
+
+	[[nodiscard]] iset key_items() const; ///< Returns the cif::iset of key item names. Retrieved from the @ref category_validator for this category
+
+	[[deprecated("use key_item_indices instead")]] [[nodiscard]] std::set<uint16_t> key_field_indices() const; ///< Returns a set of indices for the key items.
+
+	[[nodiscard]] std::set<uint16_t> key_item_indices() const; ///< Returns a set of indices for the key items.
 
 	/// @brief Set the validator for this category to @a v
 	/// @param v The category_validator to assign. A nullptr value is allowed.
@@ -200,15 +235,15 @@ class category
 
 	/// @brief Return the global @ref validator for the data
 	/// @return The @ref validator or nullptr if not assigned
-	const validator *get_validator() const { return m_validator; }
+	[[nodiscard]] const validator *get_validator() const { return m_validator; }
 
 	/// @brief Return the category validator for this category
 	/// @return The @ref category_validator or nullptr if not assigned
-	const category_validator *get_cat_validator() const { return m_cat_validator; }
+	[[nodiscard]] const category_validator *get_cat_validator() const { return m_cat_validator; }
 
 	/// @brief Validate the data stored using the assigned @ref category_validator
 	/// @return Returns true is all validations pass
-	bool is_valid() const;
+	[[nodiscard]] bool is_valid() const;
 
 	/// @brief Validate links, that means, values in this category should have an
 	/// accompanying value in parent categories.
@@ -221,7 +256,7 @@ class category
 	/// parent in those categories.
 	///
 	/// @return Returns true is all validations pass
-	bool validate_links() const;
+	[[nodiscard]] bool validate_links() const;
 
 	/**
 	 * @brief Strip removes items from this category that are invalid according to the assigned validator
@@ -248,15 +283,17 @@ class category
 	/// the category is empty.
 	reference front()
 	{
+		assert(size() > 0);
 		return { *this, *m_head };
 	}
 
 	/// @brief Return a const reference to the first row in this category.
 	/// @return const reference to the first row in this category. The result is undefined if
 	/// the category is empty.
-	const_reference front() const
+	[[nodiscard]] const_reference front() const
 	{
-		return { const_cast<category &>(*this), const_cast<row &>(*m_head) };
+		assert(size() > 0);
+		return { *this, *m_head };
 	}
 
 	/// @brief Return a reference to the last row in this category.
@@ -264,15 +301,17 @@ class category
 	/// the category is empty.
 	reference back()
 	{
+		assert(size() > 0);
 		return { *this, *m_tail };
 	}
 
 	/// @brief Return a const reference to the last row in this category.
 	/// @return const reference to the last row in this category. The result is undefined if
 	/// the category is empty.
-	const_reference back() const
+	[[nodiscard]] const_reference back() const
 	{
-		return { const_cast<category &>(*this), const_cast<row &>(*m_tail) };
+		assert(size() > 0);
+		return { *this, *m_tail };
 	}
 
 	/// Return an iterator to the first row
@@ -288,43 +327,43 @@ class category
 	}
 
 	/// Return a const iterator to the first row
-	const_iterator begin() const
+	[[nodiscard]] const_iterator begin() const
 	{
 		return { *this, m_head };
 	}
 
 	/// Return a const iterator pointing past the last row
-	const_iterator end() const
+	[[nodiscard]] const_iterator end() const
 	{
 		return { *this, nullptr };
 	}
 
 	/// Return a const iterator to the first row
-	const_iterator cbegin() const
+	[[nodiscard]] const_iterator cbegin() const
 	{
 		return { *this, m_head };
 	}
 
 	/// Return an iterator pointing past the last row
-	const_iterator cend() const
+	[[nodiscard]] const_iterator cend() const
 	{
 		return { *this, nullptr };
 	}
 
 	/// Return a count of the rows in this container
-	std::size_t size() const
+	[[nodiscard]] std::size_t size() const
 	{
 		return std::distance(cbegin(), cend());
 	}
 
 	/// Return the theoretical maximum number or rows that can be stored
-	std::size_t max_size() const
+	[[nodiscard]] std::size_t max_size() const
 	{
 		return std::numeric_limits<std::size_t>::max(); // this is a bit optimistic, I guess
 	}
 
 	/// Return true if the category is empty
-	bool empty() const
+	[[nodiscard]] bool empty() const
 	{
 		return m_head == nullptr;
 	}
@@ -336,7 +375,7 @@ class category
 	struct key_element_type
 	{
 		std::string name;         ///< Name of the item
-		std::string value;        ///< Value to be found
+		item_value value;         ///< Value to be found
 		bool may_be_null = false; ///< If true, value should be same or empty
 	};
 
@@ -348,13 +387,10 @@ class category
 	/// @return The row found in the index, or an undefined row_handle
 	row_handle operator[](const key_type &key);
 
-	/// @brief Return a const row_handle for the row specified by \a key
+	/// @brief Return a const_row_handle for the row specified by \a key
 	/// @param key The value for the key, items specified in the dictionary should have a value
 	/// @return The row found in the index, or an undefined row_handle
-	const row_handle operator[](const key_type &key) const
-	{
-		return const_cast<category *>(this)->operator[](key);
-	}
+	const_row_handle operator[](const key_type &key) const;
 
 	// --------------------------------------------------------------------
 
@@ -370,10 +406,10 @@ class category
 	/// @param names The names for the items requested
 
 	template <typename... Ts, typename... Ns>
-	iterator_proxy<const category, Ts...> rows(Ns... names) const
+	[[nodiscard]] const_iterator_proxy<Ts...> rows(Ns... names) const
 	{
 		static_assert(sizeof...(Ts) == sizeof...(Ns), "The number of item names should be equal to the number of types to return");
-		return iterator_proxy<const category, Ts...>(*this, begin(), { names... });
+		return const_iterator_proxy<Ts...>(*this, begin(), { names... });
 	}
 
 	/// @brief Return a special iterator for all rows in this category.
@@ -393,10 +429,10 @@ class category
 	/// @param names The names for the items requested
 
 	template <typename... Ts, typename... Ns>
-	iterator_proxy<category, Ts...> rows(Ns... names)
+	iterator_proxy<Ts...> rows(Ns... names)
 	{
 		static_assert(sizeof...(Ts) == sizeof...(Ns), "The number of item names should be equal to the number of types to return");
-		return iterator_proxy<category, Ts...>(*this, begin(), { names... });
+		return iterator_proxy<Ts...>(*this, begin(), { names... });
 	}
 
 	// --------------------------------------------------------------------
@@ -412,7 +448,7 @@ class category
 	/// @return A special iterator that loops over all elements that match. The iterator can be dereferenced
 	/// to a @ref row_handle
 
-	conditional_iterator_proxy<category> find(condition &&cond)
+	conditional_iterator_proxy<> find(condition &&cond)
 	{
 		return find(begin(), std::move(cond));
 	}
@@ -425,7 +461,7 @@ class category
 	/// @return A special iterator that loops over all elements that match. The iterator can be dereferenced
 	/// to a @ref row_handle
 
-	conditional_iterator_proxy<category> find(iterator pos, condition &&cond)
+	conditional_iterator_proxy<> find(iterator pos, condition &&cond)
 	{
 		return { *this, pos, std::move(cond) };
 	}
@@ -436,7 +472,7 @@ class category
 	/// @return A special iterator that loops over all elements that match. The iterator can be dereferenced
 	/// to a const @ref row_handle
 
-	conditional_iterator_proxy<const category> find(condition &&cond) const
+	const_conditional_iterator_proxy<> find(condition &&cond) const
 	{
 		return find(cbegin(), std::move(cond));
 	}
@@ -449,9 +485,9 @@ class category
 	/// @return A special iterator that loops over all elements that match. The iterator can be dereferenced
 	/// to a const @ref row_handle
 
-	conditional_iterator_proxy<const category> find(const_iterator pos, condition &&cond) const
+	const_conditional_iterator_proxy<> find(const_iterator pos, condition &&cond) const
 	{
-		return conditional_iterator_proxy<const category>{ *this, pos, std::move(cond) };
+		return const_conditional_iterator_proxy<>{ *this, pos, std::move(cond) };
 	}
 
 	/// @brief Return a special iterator to loop over all rows that conform to @a cond. The resulting
@@ -468,10 +504,10 @@ class category
 	/// @return A special iterator that loops over all elements that match.
 
 	template <typename... Ts, typename... Ns>
-	conditional_iterator_proxy<category, Ts...> find(condition &&cond, Ns... names)
+	conditional_iterator_proxy<Ts...> find(condition &&cond, Ns... names)
 	{
 		static_assert(sizeof...(Ts) == sizeof...(Ns), "The number of item names should be equal to the number of types to return");
-		return find<Ts...>(cbegin(), std::move(cond), std::forward<Ns>(names)...);
+		return find<Ts...>(begin(), std::move(cond), std::forward<Ns>(names)...);
 	}
 
 	/// @brief Return a special const iterator to loop over all rows that conform to @a cond. The resulting
@@ -483,7 +519,7 @@ class category
 	/// @return A special iterator that loops over all elements that match.
 
 	template <typename... Ts, typename... Ns>
-	conditional_iterator_proxy<const category, Ts...> find(condition &&cond, Ns... names) const
+	const_conditional_iterator_proxy<Ts...> find(condition &&cond, Ns... names) const
 	{
 		static_assert(sizeof...(Ts) == sizeof...(Ns), "The number of item names should be equal to the number of types to return");
 		return find<Ts...>(cbegin(), std::move(cond), std::forward<Ns>(names)...);
@@ -499,7 +535,7 @@ class category
 	/// @return A special iterator that loops over all elements that match.
 
 	template <typename... Ts, typename... Ns>
-	conditional_iterator_proxy<category, Ts...> find(const_iterator pos, condition &&cond, Ns... names)
+	conditional_iterator_proxy<Ts...> find(iterator pos, condition &&cond, Ns... names)
 	{
 		static_assert(sizeof...(Ts) == sizeof...(Ns), "The number of item names should be equal to the number of types to return");
 		return { *this, pos, std::move(cond), std::forward<Ns>(names)... };
@@ -515,7 +551,7 @@ class category
 	/// @return A special iterator that loops over all elements that match.
 
 	template <typename... Ts, typename... Ns>
-	conditional_iterator_proxy<const category, Ts...> find(const_iterator pos, condition &&cond, Ns... names) const
+	const_conditional_iterator_proxy<Ts...> find(const_iterator pos, condition &&cond, Ns... names) const
 	{
 		static_assert(sizeof...(Ts) == sizeof...(Ns), "The number of item names should be equal to the number of types to return");
 		return { *this, pos, std::move(cond), std::forward<Ns>(names)... };
@@ -552,7 +588,7 @@ class category
 	/// there are is not exactly one row matching @a cond
 	/// @param cond The condition to search for
 	/// @return Row handle to the row found
-	const row_handle find1(condition &&cond) const
+	const_row_handle find1(condition &&cond) const
 	{
 		return find1(cbegin(), std::move(cond));
 	}
@@ -562,7 +598,7 @@ class category
 	/// @param pos The position to start the search
 	/// @param cond The condition to search for
 	/// @return Row handle to the row found
-	const row_handle find1(const_iterator pos, condition &&cond) const
+	const_row_handle find1(const_iterator pos, condition &&cond) const
 	{
 		auto h = find(pos, std::move(cond));
 
@@ -580,10 +616,30 @@ class category
 	/// @return The value found
 	template <typename T>
 	T find1(condition &&cond, std::string_view item) const
+		requires(not is_optional_v<T>)
 	{
 		return find1<T>(cbegin(), std::move(cond), item);
 	}
 
+	/// @brief Return value for the item named @a item for the single row that
+	/// matches @a cond. Throws @a multiple_results_error if there are is not exactly one row
+	/// @tparam The type to use for the result
+	/// @param cond The condition to search for
+	/// @param item The name of the item to return the value for
+	/// @return The value found
+
+	template <typename T>
+	T find1(condition &&cond, std::string_view item) const
+		requires(is_optional_v<T>)
+	{
+		auto h = find<typename T::value_type>(cbegin(), std::move(cond), item);
+
+		if (h.size() == 1)
+			return *h.begin();
+
+		return T{};
+	}
+
 	/// @brief Return value for the item named @a item for the single row that
 	/// matches @a cond when starting to search at @a pos.
 	/// Throws @a multiple_results_error if there are is not exactly one row
@@ -592,8 +648,9 @@ class category
 	/// @param cond The condition to search for
 	/// @param item The name of the item to return the value for
 	/// @return The value found
-	template <typename T, std::enable_if_t<not is_optional_v<T>, int> = 0>
+	template <typename T>
 	T find1(const_iterator pos, condition &&cond, std::string_view item) const
+		requires(not is_optional_v<T>)
 	{
 		auto h = find<T>(pos, std::move(cond), item);
 
@@ -611,8 +668,9 @@ class category
 	/// @param cond The condition to search for
 	/// @param item The name of the item to return the value for
 	/// @return The value found, can be empty if no row matches the condition
-	template <typename T, std::enable_if_t<is_optional_v<T>, int> = 0>
+	template <typename T>
 	T find1(const_iterator pos, condition &&cond, std::string_view item) const
+		requires(is_optional_v<T>)
 	{
 		auto h = find<typename T::value_type>(pos, std::move(cond), item);
 
@@ -620,7 +678,7 @@ class category
 			throw multiple_results_error();
 
 		if (h.empty())
-			return {};
+			return std::nullopt;
 
 		return *h.begin();
 	}
@@ -685,7 +743,7 @@ class category
 	/// @brief Return a const row handle to the first row that matches @a cond
 	/// @param cond The condition to search for
 	/// @return The const handle to the row that matches or an empty row_handle
-	const row_handle find_first(condition &&cond) const
+	const_row_handle find_first(condition &&cond) const
 	{
 		return find_first(cbegin(), std::move(cond));
 	}
@@ -694,11 +752,11 @@ class category
 	/// @param pos The location to start searching
 	/// @param cond The condition to search for
 	/// @return The const handle to the row that matches or an empty row_handle
-	const row_handle find_first(const_iterator pos, condition &&cond) const
+	const_row_handle find_first(const_iterator pos, condition &&cond) const
 	{
 		auto h = find(pos, std::move(cond));
 
-		return h.empty() ? row_handle{} : *h.begin();
+		return h.empty() ? const_row_handle{} : *h.begin();
 	}
 
 	/// @brief Return the value for item @a item for the first row that matches condition @a cond
@@ -763,8 +821,9 @@ class category
 	/// @param item The item to use for the value
 	/// @param cond The condition to search for
 	/// @return The value found or the minimal value for the type
-	template <typename T, std::enable_if_t<std::is_arithmetic_v<T>, int> = 0>
+	template <typename T>
 	T find_max(std::string_view item, condition &&cond) const
+		requires(std::is_arithmetic_v<T>)
 	{
 		T result = std::numeric_limits<T>::min();
 
@@ -781,8 +840,9 @@ class category
 	/// @tparam The type of the value to return
 	/// @param item The item to use for the value
 	/// @return The value found or the minimal value for the type
-	template <typename T, std::enable_if_t<std::is_arithmetic_v<T>, int> = 0>
-	T find_max(std::string_view item) const
+	template <typename T>
+	[[nodiscard]] T find_max(std::string_view item) const
+		requires(std::is_arithmetic_v<T>)
 	{
 		return find_max<T>(item, all());
 	}
@@ -792,8 +852,9 @@ class category
 	/// @param item The item to use for the value
 	/// @param cond The condition to search for
 	/// @return The value found or the maximum value for the type
-	template <typename T, std::enable_if_t<std::is_arithmetic_v<T>, int> = 0>
-	T find_min(std::string_view item, condition &&cond) const
+	template <typename T>
+	[[nodiscard]] T find_min(std::string_view item, condition &&cond) const
+		requires(std::is_arithmetic_v<T>)
 	{
 		T result = std::numeric_limits<T>::max();
 
@@ -810,8 +871,9 @@ class category
 	/// @tparam The type of the value to return
 	/// @param item The item to use for the value
 	/// @return The value found or the maximum value for the type
-	template <typename T, std::enable_if_t<std::is_arithmetic_v<T>, int> = 0>
-	T find_min(std::string_view item) const
+	template <typename T>
+	[[nodiscard]] T find_min(std::string_view item) const
+		requires(std::is_arithmetic_v<T>)
 	{
 		return find_min<T>(item, all());
 	}
@@ -831,10 +893,8 @@ class category
 	{
 		bool result = false;
 
-		if (cond)
+		if (cond and cond.prepare(*this))
 		{
-			cond.prepare(*this);
-
 			auto sh = cond.single();
 
 			if (sh.has_value() and *sh)
@@ -862,10 +922,8 @@ class category
 	{
 		std::size_t result = 0;
 
-		if (cond)
+		if (cond and cond.prepare(*this))
 		{
-			cond.prepare(*this);
-
 			auto sh = cond.single();
 
 			if (sh.has_value() and *sh)
@@ -887,36 +945,38 @@ class category
 
 	/// Using the relations defined in the validator, return whether the row
 	/// in @a r has any children in other categories
-	bool has_children(row_handle r) const;
+	[[nodiscard]] bool has_children(const_row_handle r) const;
 
 	/// Using the relations defined in the validator, return whether the row
 	/// in @a r has any parents in other categories
-	bool has_parents(row_handle r) const;
+	[[nodiscard]] bool has_parents(const_row_handle r) const;
 
 	/// Using the relations defined in the validator, return the row handles
 	/// for all rows in @a childCat that are linked to row @a r
-	std::vector<row_handle> get_children(row_handle r, const category &childCat) const;
+	[[nodiscard]] std::vector<const_row_handle> get_children(const_row_handle r, const category &childCat) const;
 
 	/// Using the relations defined in the validator, return the row handles
 	/// for all rows in @a parentCat that are linked to row @a r
-	std::vector<row_handle> get_parents(row_handle r, const category &parentCat) const;
+	[[nodiscard]] std::vector<const_row_handle> get_parents(const_row_handle r, const category &parentCat) const;
 
 	/// Using the relations defined in the validator, return the row handles
 	/// for all rows in @a cat that are in any way linked to row @a r
-	std::vector<row_handle> get_linked(row_handle r, const category &cat) const;
+	[[nodiscard]] std::vector<const_row_handle> get_linked(const_row_handle r, const category &cat) const;
+
+	/// Using the relations defined in the validator, return the row handles
+	/// for all rows in @a childCat that are linked to row @a r
+	[[nodiscard]] std::vector<row_handle> get_children(row_handle r, category &childCat);
+
+	/// Using the relations defined in the validator, return the row handles
+	/// for all rows in @a parentCat that are linked to row @a r
+	[[nodiscard]] std::vector<row_handle> get_parents(row_handle r, category &parentCat);
+
+	/// Using the relations defined in the validator, return the row handles
+	/// for all rows in @a cat that are in any way linked to row @a r
+	[[nodiscard]] std::vector<row_handle> get_linked(row_handle r, category &cat);
 
 	// --------------------------------------------------------------------
 
-	// void insert(const_iterator pos, const row_initializer &row)
-	// {
-	// 	insert_impl(pos, row);
-	// }
-
-	// void insert(const_iterator pos, row_initializer &&row)
-	// {
-	// 	insert_impl(pos, std::move(row));
-	// }
-
 	/// Erase the row pointed to by @a pos and return the iterator to the
 	/// row following pos.
 	iterator erase(iterator pos);
@@ -948,8 +1008,8 @@ class category
 	}
 
 	/// @brief Create a new row and emplace the values in the range @a b to @a e in it
-	/// @param b Iterator to the beginning of the range of @ref item_value
-	/// @param e Iterator to the end of the range of @ref item_value
+	/// @param b Iterator to the beginning of the range of item_values
+	/// @param e Iterator to the end of the range of item_values
 	/// @return iterator to the newly created row
 	template <typename ItemIter>
 	iterator emplace(ItemIter b, ItemIter e)
@@ -961,7 +1021,7 @@ class category
 			for (auto i = b; i != e; ++i)
 			{
 				// item_value *new_item = this->create_item(*i);
-				r->append(add_item(i->name()), { i->value() });
+				r->set(add_item(i->name()), i->value());
 			}
 		}
 		catch (...)
@@ -974,6 +1034,7 @@ class category
 		return insert_impl(cend(), r);
 	}
 
+	/// Create rows with the content of the data in [ @a b, to @a e)
 	void emplace(const_iterator b, const_iterator e)
 	{
 		while (b != e)
@@ -1005,7 +1066,9 @@ class category
 
 	// --------------------------------------------------------------------
 
-	using value_provider_type = std::function<std::string_view(std::string_view)>;
+	/// The type for a function that provides a value to insert based on a
+	/// value that is the default or the previous value
+	using value_provider_type = std::function<item_value(const item_value &)>;
 
 	/// \brief Update a single item named @a item_name in the rows that match
 	/// \a cond to values provided by a callback function \a value_provider
@@ -1018,6 +1081,7 @@ class category
 	{
 		auto rs = find(std::move(cond));
 		std::vector<row_handle> rows;
+		// NOLINTNEXTLINE
 		std::copy(rs.begin(), rs.end(), std::back_inserter(rows));
 		update_value(rows, item_name, std::move(value_provider));
 	}
@@ -1036,10 +1100,11 @@ class category
 	/// That means, child categories are updated if the links are absolute
 	/// and unique. If they are not, the child category rows are split.
 
-	void update_value(condition &&cond, std::string_view item_name, std::string_view value)
+	void update_value(condition &&cond, std::string_view item_name, const item_value &value)
 	{
 		auto rs = find(std::move(cond));
 		std::vector<row_handle> rows;
+		// NOLINTNEXTLINE
 		std::copy(rs.begin(), rs.end(), std::back_inserter(rows));
 		update_value(rows, item_name, value);
 	}
@@ -1049,75 +1114,21 @@ class category
 	/// That means, child categories are updated if the links are absolute
 	/// and unique. If they are not, the child category rows are split.
 
-	void update_value(const std::vector<row_handle> &rows, std::string_view item_name, std::string_view value)
+	void update_value(const std::vector<row_handle> &rows, std::string_view item_name, const item_value &value)
 	{
-		update_value(rows, item_name, [value](std::string_view)
+		update_value(rows, item_name, [value](const item_value &)
 			{ return value; });
 	}
 
-	// --------------------------------------------------------------------
-	// Naming used to be very inconsistent. For backward compatibility,
-	// the old function names are here as deprecated variants.
-
-	/// \brief Return the index number for \a column_name
-	[[deprecated("Use get_item_ix instead")]] uint16_t get_column_ix(std::string_view column_name) const
-	{
-		return get_item_ix(column_name);
-	}
-
-	/// @brief Return the name for column with index @a ix
-	/// @param ix The index number
-	/// @return The name of the column
-	[[deprecated("use get_item_name instead")]] std::string_view get_column_name(uint16_t ix) const
-	{
-		return get_item_name(ix);
-	}
-
-	/// @brief Make sure a item with name @a item_name is known and return its index number
-	/// @param item_name The name of the item
-	/// @return The index number of the item
-	[[deprecated("use add_item instead")]] uint16_t add_column(std::string_view item_name)
-	{
-		return add_item(item_name);
-	}
-
-	/** @brief Remove column name @a colum_name
-	 * @param column_name The column to be removed
-	 */
-	[[deprecated("use remove_item instead")]] void remove_column(std::string_view column_name)
-	{
-		remove_item(column_name);
-	}
-
-	/** @brief Rename column @a from_name to @a to_name */
-	[[deprecated("use rename_item instead")]] void rename_column(std::string_view from_name, std::string_view to_name)
-	{
-		rename_item(from_name, to_name);
-	}
-
-	/// @brief Return whether a column with name @a name exists in this category
-	/// @param name The name of the column
-	/// @return True if the column exists
-	[[deprecated("use has_item instead")]] bool has_column(std::string_view name) const
-	{
-		return has_item(name);
-	}
-
-	/// @brief Return the cif::iset of columns in this category
-	[[deprecated("use get_items instead")]] iset get_columns() const
-	{
-		return get_items();
-	}
-
 	// --------------------------------------------------------------------
 	/// \brief Return the index number for \a item_name
 
-	uint16_t get_item_ix(std::string_view item_name) const;
+	[[nodiscard]] uint16_t get_item_ix(std::string_view item_name) const;
 
 	/// @brief Return the name for item with index @a ix
 	/// @param ix The index number
 	/// @return The name of the item
-	std::string_view get_item_name(uint16_t ix) const
+	[[nodiscard]] const std::string &get_item_name(uint16_t ix) const
 	{
 		if (ix >= m_items.size())
 			throw std::out_of_range("item index is out of range");
@@ -1135,19 +1146,28 @@ class category
 	 */
 	void remove_item(std::string_view item_name);
 
+	/// \brief Drop items in this category that contain empty values in all rows.
+	void drop_empty_items();
+
 	/** @brief Rename item @a from_name to @a to_name */
 	void rename_item(std::string_view from_name, std::string_view to_name);
 
 	/// @brief Return whether a item with name @a name exists in this category
 	/// @param name The name of the item
 	/// @return True if the item exists
-	bool has_item(std::string_view name) const
+	[[nodiscard]] bool has_item(std::string_view name) const
 	{
 		return get_item_ix(name) < m_items.size();
 	}
 
-	/// @brief Return the cif::iset of items in this category
-	iset get_items() const;
+	/// @brief Return the items in this category
+	[[nodiscard]] std::vector<std::string> get_items() const;
+
+	/// @brief Return the number of items (colums) in this category
+	[[nodiscard]] constexpr uint16_t get_item_count() const noexcept
+	{
+		return m_items.size();
+	}
 
 	// --------------------------------------------------------------------
 
@@ -1162,31 +1182,55 @@ class category
 	void reorder_by_index();
 
 	// --------------------------------------------------------------------
-
 	/// This function returns effectively the list of fully qualified item
 	/// names, that is category_name + '.' + item_name for each item
-	[[deprecated("use get_item_order instead")]] std::vector<std::string> get_tag_order() const
-	{
-		return get_item_order();
-	}
-
-	/// This function returns effectively the list of fully qualified item
-	/// names, that is category_name + '.' + item_name for each item
-	std::vector<std::string> get_item_order() const;
+	[[nodiscard]] std::vector<std::string> get_item_order() const;
 
 	/// Write the contents of the category to the std::ostream @a os
 	void write(std::ostream &os) const;
 
+	/// \brief Various supported output formats
+	enum class output_format
+	{
+		cif,      // Output in mmCIF format
+		csv,      // comma separated values
+		tsv,      // tab separated values
+		list,     // values delimited by a '|' character
+		column,   // output in columns
+		markdown, //
+		table,    // ascii art table
+		box,      // table with unicode line characters
+	};
+
+	/// @brief
+	/// @brief Write the contents of the category to the std::ostream @a os and
+	/// use @a order as the order of the items. If @a addMissingItems is
+	/// false, items that do not contain any value will be suppressed. Use this version
+	/// to write out
+	/// @param os The std::ostream to write to
+	/// @param fmt The format to use
+	/// @param order The order in which the items should appear
+	/// @param addMissingItems When false, empty items are suppressed from the output
+	void write(std::ostream &os, output_format fmt,
+		const std::vector<std::string> &order, bool addMissingItems = true);
+
 	/// @brief Write the contents of the category to the std::ostream @a os and
 	/// use @a order as the order of the items. If @a addMissingItems is
 	/// false, items that do not contain any value will be suppressed
 	/// @param os The std::ostream to write to
 	/// @param order The order in which the items should appear
 	/// @param addMissingItems When false, empty items are suppressed from the output
-	void write(std::ostream &os, const std::vector<std::string> &order, bool addMissingItems = true);
+	void write(std::ostream &os, const std::vector<std::string> &order, bool addMissingItems = true)
+	{
+		write(os, output_format::cif, order, addMissingItems);
+	}
 
   private:
-	void write(std::ostream &os, const std::vector<uint16_t> &order, bool includeEmptyItems) const;
+	void write_cif(std::ostream &os, const std::vector<uint16_t> &order, bool includeEmptyItems) const;
+	void write_delimited(std::ostream &os, const std::vector<uint16_t> &order, bool includeEmptyItems,
+		std::string_view delimiter, bool aligned, bool header) const;
+	void write_markdown(std::ostream &os, const std::vector<uint16_t> &order, bool includeEmptyItems) const;
+	void write_table(std::ostream &os, const std::vector<uint16_t> &order, bool includeEmptyItems, bool ascii) const;
 
   public:
 	/// friend function to make it possible to do:
@@ -1200,13 +1244,13 @@ class category
 	}
 
   private:
-	void update_value(row *row, uint16_t item, std::string_view value, bool updateLinked, bool validate = true);
+	void update_value(row *row, uint16_t item, item_value value, bool updateLinked, bool validate = true);
 
 	void erase_orphans(condition &&cond, category &parent);
 
 	using allocator_type = std::allocator<void>;
 
-	constexpr allocator_type get_allocator() const
+	[[nodiscard]] constexpr allocator_type get_allocator() const
 	{
 		return {};
 	}
@@ -1235,6 +1279,8 @@ class category
 
 	void delete_row(row *r);
 
+	iterator erase(iterator pos, bool cascade);
+
 	row_handle create_copy(row_handle r);
 
 	struct item_entry
@@ -1257,7 +1303,7 @@ class category
 		{
 		}
 
-		// TODO: NEED TO FIX THIS!
+		// TODO: NEED TO FIX THIS! (but what was it that needs to be fixed?)
 		category *linked;
 		const link_validator *v;
 	};
@@ -1268,8 +1314,8 @@ class category
 
 	// --------------------------------------------------------------------
 
-	condition get_parents_condition(row_handle rh, const category &parentCat) const;
-	condition get_children_condition(row_handle rh, const category &childCat) const;
+	[[nodiscard]] condition get_parents_condition(const_row_handle rh, const category &parentCat) const;
+	[[nodiscard]] condition get_children_condition(const_row_handle rh, const category &childCat) const;
 
 	// --------------------------------------------------------------------
 
@@ -1282,10 +1328,13 @@ class category
 	const validator *m_validator = nullptr;
 	const category_validator *m_cat_validator = nullptr;
 	std::vector<link> m_parent_links, m_child_links;
-	bool m_cascade = true;
 	uint32_t m_last_unique_num = 0;
 	class category_index *m_index = nullptr;
 	row *m_head = nullptr, *m_tail = nullptr;
+
+	bool m_dirty = false; // Keep track of modifications
 };
 
+static_assert(std::ranges::input_range<category>);
+
 } // namespace cif

include/cif++/cif++.hpp

@@ -26,8 +26,28 @@
 
 #pragma once
 
-/// \file cif2pdb.hpp
-/// \deprecated This file is no longer used. Please use "cif++/pdb.hpp" instead
-
-#warning "Use of this file is deprecated, please use "cif++/pdb.hpp"
-
+// IWYU pragma: begin_exports
+#include "cif++/atom_type.hpp"
+#include "cif++/category.hpp"
+#include "cif++/compound.hpp"
+#include "cif++/condition.hpp"
+#include "cif++/cql.hpp"
+#include "cif++/datablock.hpp"
+#include "cif++/dictionary_parser.hpp"
+#include "cif++/exports.hpp"
+#include "cif++/file.hpp"
+#include "cif++/format.hpp"
+#include "cif++/gzio.hpp"
+#include "cif++/item.hpp"
+#include "cif++/iterator.hpp"
+#include "cif++/matrix.hpp"
+#include "cif++/model.hpp"
+#include "cif++/parser.hpp"
+#include "cif++/pdb.hpp"
+#include "cif++/point.hpp"
+#include "cif++/row.hpp"
+#include "cif++/symmetry.hpp"
+#include "cif++/text.hpp"
+#include "cif++/utilities.hpp"
+#include "cif++/validate.hpp"
+// IWYU pragma: end_exports

include/cif++/compound.hpp

@@ -26,15 +26,16 @@
 
 #pragma once
 
-#include "cif++/atom_type.hpp"
 #include "cif++/datablock.hpp"
 #include "cif++/exports.hpp"
 #include "cif++/point.hpp"
-#include "cif++/utilities.hpp"
 
+#include <cstdint>
+#include <filesystem>
 #include <map>
-#include <set>
-#include <tuple>
+#include <memory>
+#include <string>
+#include <string_view>
 #include <vector>
 
 /// \file compound.hpp
@@ -53,9 +54,10 @@ namespace cif
 
 // --------------------------------------------------------------------
 
-class compound;
-struct compound_atom;
 class compound_factory_impl;
+class datablock;
+class file;
+enum atom_type : uint8_t;
 
 /// \brief The bond type or bond order as defined in the CCD, possible values taken from the mmcif_pdbx file
 enum class bond_type
@@ -116,7 +118,7 @@ struct compound_atom
 		z;                                                    ///< The z component of the coordinates for each atom specified as orthogonal angstroms.
 
 	/// Return the location of the atom as a point
-	point get_location() const
+	[[nodiscard]] point get_location() const
 	{
 		return { x, y, z };
 	}
@@ -146,40 +148,43 @@ class compound
   public:
 	// accessors
 
-	std::string id() const { return m_id; }                   ///< Return the alphanumeric code for the chemical component.
-	std::string name() const { return m_name; }               ///< Return the name of the chemical component.
-	std::string type() const { return m_type; }               ///< Return the type of monomer.
-	std::string formula() const { return m_formula; }         ///< Return the chemical formula of the chemical component.
-	float formula_weight() const { return m_formula_weight; } ///< Return the formula mass of the chemical component in Daltons.
-	int formal_charge() const { return m_formal_charge; }     ///< Return the formal charge on the chemical component.
+	[[nodiscard]] std::string id() const { return m_id; }                   ///< Return the alphanumeric code for the chemical component.
+	[[nodiscard]] std::string name() const { return m_name; }               ///< Return the name of the chemical component.
+	[[nodiscard]] std::string type() const { return m_type; }               ///< Return the type of monomer.
+	[[nodiscard]] std::string formula() const { return m_formula; }         ///< Return the chemical formula of the chemical component.
+	[[nodiscard]] float formula_weight() const { return m_formula_weight; } ///< Return the formula mass of the chemical component in Daltons.
+	[[nodiscard]] int formal_charge() const { return m_formal_charge; }     ///< Return the formal charge on the chemical component.
 
-	const std::vector<compound_atom> &atoms() const { return m_atoms; } ///< Return the list of atoms for this compound
-	const std::vector<compound_bond> &bonds() const { return m_bonds; } ///< Return the list of bonds for this compound
+	[[nodiscard]] const std::vector<compound_atom> &atoms() const { return m_atoms; } ///< Return the list of atoms for this compound
+	[[nodiscard]] const std::vector<compound_bond> &bonds() const { return m_bonds; } ///< Return the list of bonds for this compound
 
-	compound_atom get_atom_by_atom_id(const std::string &atom_id) const; ///< Return the atom with id @a atom_id
+	[[nodiscard]] compound_atom get_atom_by_atom_id(const std::string &atom_id) const; ///< Return the atom with id @a atom_id
 
-	bool atoms_bonded(const std::string &atomId_1, const std::string &atomId_2) const; ///< Return true if @a atomId_1 is bonded to @a atomId_2
-	float bond_length(const std::string &atomId_1, const std::string &atomId_2) const; ///< Return the bond length between @a atomId_1 and @a atomId_2
+	[[nodiscard]] bool atoms_bonded(const std::string &atomId_1, const std::string &atomId_2) const; ///< Return true if @a atomId_1 is bonded to @a atomId_2
+	[[nodiscard]] float bond_length(const std::string &atomId_1, const std::string &atomId_2) const; ///< Return the bond length between @a atomId_1 and @a atomId_2
 
-	bool is_water() const ///< Return if the compound is actually a water
+	[[nodiscard]] bool is_water() const ///< Return if the compound is actually a water
 	{
 		return m_id == "HOH" or m_id == "H2O" or m_id == "WAT";
 	}
 
 	/** \brief Return whether this compound has a type of either 'peptide linking' or 'L-peptide linking' */
-	bool is_peptide() const;
+	[[nodiscard]] bool is_peptide() const;
 
 	/** \brief Return whether this compound has a type of either 'DNA linking' or 'RNA linking' */
-	bool is_base() const;
+	[[nodiscard]] bool is_base() const;
 
-	char one_letter_code() const { return m_one_letter_code; }; ///< Return the one letter code to use in a canonical sequence. If unknown the value '\0' is returned
-	std::string parent_id() const { return m_parent_id; };      ///< Return the parent id code in case a parent is specified (e.g. MET for MSE)
+	/// Return the one letter code to use in a canonical sequence. If unknown the value '\0' is returned
+	[[nodiscard]] char one_letter_code() const { return m_one_letter_code; };
+
+	/// Return the parent id code in case a parent is specified (e.g. MET for MSE)
+	[[nodiscard]] std::string parent_id() const { return m_parent_id; };
 
   private:
 	friend class compound_factory_impl;
 	friend class local_compound_factory_impl;
 
-	compound(cif::datablock &db);
+	compound(datablock &db);
 
 	std::string m_id;
 	std::string m_name;
@@ -201,6 +206,9 @@ class compound
 class compound_factory
 {
   public:
+	compound_factory(const compound_factory &) = delete;
+	compound_factory &operator=(const compound_factory &) = delete;
+
 	/// \brief Initialise a singleton instance.
 	///
 	/// If you have a multithreaded application and want to have different
@@ -243,38 +251,44 @@ class compound_factory
 
 	/// Return whether @a res_name is a valid and known peptide
 	[[deprecated("use is_peptide or is_std_peptide instead)")]]
-	bool is_known_peptide(const std::string &res_name) const;
+	[[nodiscard]] bool
+	is_known_peptide(const std::string &res_name) const;
 
 	/// Return whether @a res_name is a valid and known base
 	[[deprecated("use is_base or is_std_base instead)")]]
-	bool is_known_base(const std::string &res_name) const;
+	[[nodiscard]] bool
+	is_known_base(const std::string &res_name) const;
 
 	/// Return whether @a res_name is a peptide
-	bool is_peptide(std::string_view res_name) const;
+	[[nodiscard]] bool is_peptide(std::string_view res_name) const;
 
 	/// Return whether @a res_name is a base
-	bool is_base(std::string_view res_name) const;
+	[[nodiscard]] bool is_base(std::string_view res_name) const;
 
 	/// Return whether @a res_name is one of the standard peptides
-	bool is_std_peptide(std::string_view res_name) const;
+	[[nodiscard]] bool is_std_peptide(std::string_view res_name) const;
 
 	/// Return whether @a res_name is one of the standard bases
-	bool is_std_base(std::string_view res_name) const;
+	[[nodiscard]] bool is_std_base(std::string_view res_name) const;
 
 	/// Return whether @a res_name is a monomer (either base or peptide)
-	bool is_monomer(std::string_view res_name) const;
+	[[nodiscard]] bool is_monomer(std::string_view res_name) const;
 
 	/// Return whether @a res_name is one of the standard bases or peptides
-	bool is_std_monomer(std::string_view res_name) const
+	[[nodiscard]] bool is_std_monomer(std::string_view res_name) const
 	{
 		return is_std_base(res_name) or is_std_peptide(res_name);
 	}
 
-	bool is_water(std::string_view res_name) const
+	/// Return whether @a res_name is water
+	[[nodiscard]] bool is_water(std::string_view res_name) const
 	{
 		return res_name == "HOH" or res_name == "H2O" or res_name == "WAT";
 	}
 
+	/// Return whether @a res_name already exists, without creating it.
+	[[nodiscard]] bool exists(std::string_view res_name) const;
+
 	/// \brief Create the compound object for \a id
 	///
 	/// This will create the compound instance for \a id if it doesn't exist already.
@@ -283,15 +297,18 @@ class compound_factory
 	/// \result		The compound, or nullptr if it could not be created (missing info)
 	const compound *create(std::string_view id);
 
-	~compound_factory();
+	~compound_factory() = default;
 
 	CIFPP_EXPORT static const std::map<std::string, char> kAAMap, ///< Globally accessible static list of the default amino acids
 		kBaseMap;                                                 ///< Globally accessible static list of the default bases
 
+	/// Print out a message for a missing compound
 	void report_missing_compound(std::string_view compound_id);
 
-	bool get_report_missing() const { return m_report_missing; }
+	/// Return a flag indicating if we need to print out a report
+	[[nodiscard]] bool get_report_missing() const { return m_report_missing; }
 
+	/// Set a flag indicating if we need to print out a report
 	void set_report_missing(bool report)
 	{
 		m_report_missing = report;
@@ -300,9 +317,6 @@ class compound_factory
   private:
 	compound_factory();
 
-	compound_factory(const compound_factory &) = delete;
-	compound_factory &operator=(const compound_factory &) = delete;
-
 	static std::unique_ptr<compound_factory> s_instance;
 	static thread_local std::unique_ptr<compound_factory> tl_instance;
 	static bool s_use_thread_local_instance;
@@ -331,14 +345,15 @@ class compound_factory
 class compound_source
 {
   public:
-	compound_source(const cif::file &file)
+    /// Constructor
+	compound_source(const file &file)
 	{
-		cif::compound_factory::instance().push_dictionary(file);
+		compound_factory::instance().push_dictionary(file);
 	}
 
 	~compound_source()
 	{
-		cif::compound_factory::instance().pop_dictionary();
+		compound_factory::instance().pop_dictionary();
 	}
 };
 

include/cif++/condition.hpp

@@ -26,15 +26,24 @@
 
 #pragma once
 
+#include "cif++/item.hpp"
 #include "cif++/row.hpp"
-#include "cif++/format.hpp"
+#include "cif++/text.hpp"
 
 #include <cassert>
-#include <concepts>
+#include <cstddef>
+#include <cstdint>
+#include <format>
 #include <functional>
 #include <iostream>
+#include <optional>
 #include <regex>
+#include <string>
+#include <string_view>
+#include <type_traits>
+#include <typeinfo>
 #include <utility>
+#include <vector>
 
 /** \file condition.hpp
  * This file contains code to create conditions: object encapsulating a
@@ -127,9 +136,9 @@ iset get_category_items(const category &cat);
  *
  * @param cat The category
  * @param col The name of the item
- * @return uint16_t The index
+ * @return uint16_t The index, if item is found
  */
-uint16_t get_item_ix(const category &cat, std::string_view col);
+std::optional<uint16_t> get_item_ix(const category &cat, std::string_view col);
 
 /**
  * @brief Return whether the item @a col in category @a cat has a primitive type of *uchar*
@@ -143,24 +152,25 @@ bool is_item_type_uchar(const category &cat, std::string_view col);
 
 // --------------------------------------------------------------------
 // some more templates to be able to do querying
+/// @cond
 
 namespace detail
 {
 	struct condition_impl
 	{
-		virtual ~condition_impl() {}
+		virtual ~condition_impl() = default;
 
 		virtual condition_impl *prepare(const category &) { return this; }
-		virtual bool test(row_handle) const = 0;
+		[[nodiscard]] virtual bool test(const_row_handle) const = 0;
 		virtual void str(std::ostream &) const = 0;
-		virtual std::optional<row_handle> single() const { return {}; };
+		[[nodiscard]] virtual std::optional<const_row_handle> single() const { return std::nullopt; };
 
 		virtual bool equals([[maybe_unused]] const condition_impl *rhs) const { return false; }
 	};
 
 	struct all_condition_impl : public condition_impl
 	{
-		bool test(row_handle) const override { return true; }
+		[[nodiscard]] bool test(const_row_handle) const override { return true; }
 		void str(std::ostream &os) const override { os << "*"; }
 	};
 
@@ -169,6 +179,8 @@ namespace detail
 	struct not_condition_impl;
 } // namespace detail
 
+/// @endcond
+
 /**
  * @brief The interface class for conditions. This uses the bridge pattern,
  * which means the implementation is in the member m_impl
@@ -207,7 +219,7 @@ class condition
 	condition(condition &&rhs) noexcept
 		: m_impl(nullptr)
 	{
-		std::swap(m_impl, rhs.m_impl);
+		swap(*this, rhs);
 	}
 
 	condition &operator=(const condition &) = delete;
@@ -217,7 +229,7 @@ class condition
 	 */
 	condition &operator=(condition &&rhs) noexcept
 	{
-		std::swap(m_impl, rhs.m_impl);
+		swap(*this, rhs);
 		return *this;
 	}
 
@@ -232,8 +244,9 @@ class condition
 	 * take care of setting the correct indices for items e.g.
 	 *
 	 * @param c The category this query should act upon
+	 * @result Returns true if the condition might result in rows
 	 */
-	void prepare(const category &c);
+	bool prepare(const category &c);
 
 	/**
 	 * @brief This operator returns true if the row referenced by @a r is
@@ -243,33 +256,32 @@ class condition
 	 * @return true If there is a match
 	 * @return false If there is no match
 	 */
-	bool operator()(row_handle r) const
+	bool operator()(const_row_handle r) const
 	{
 		assert(this->m_impl != nullptr);
-		assert(this->m_prepared);
 		return m_impl ? m_impl->test(r) : false;
 	}
 
 	/**
 	 * @brief Return true if the condition is not empty
 	 */
-	explicit operator bool() { return not empty(); }
+	explicit operator bool() const { return not empty(); }
 
 	/**
 	 * @brief Return true if the condition is empty, has no condition
 	 */
-	bool empty() const { return m_impl == nullptr; }
+	[[nodiscard]] bool empty() const { return m_impl == nullptr; }
 
 	/**
 	 * @brief If the prepare step found out there is only one hit
 	 * this single hit can be returned by this method.
 	 *
-	 * @return std::optional<row_handle> The result will contain
+	 * @return std::optional<const_row_handle> The result will contain
 	 * a row reference if there is a single hit, it will be empty otherwise
 	 */
-	std::optional<row_handle> single() const
+	[[nodiscard]] std::optional<const_row_handle> single() const
 	{
-		return m_impl ? m_impl->single() : std::optional<row_handle>();
+		return m_impl ? m_impl->single() : std::optional<const_row_handle>();
 	}
 
 	friend condition operator||(condition &&a, condition &&b); /**< Return a condition which is the logical OR or condition @a and @b */
@@ -284,10 +296,9 @@ class condition
 	/**
 	 * @brief Swap two conditions
 	 */
-	void swap(condition &rhs)
+	friend void swap(condition &lhs, condition &rhs) noexcept
 	{
-		std::swap(m_impl, rhs.m_impl);
-		std::swap(m_prepared, rhs.m_prepared);
+		std::swap(lhs.m_impl, rhs.m_impl);
 	}
 
 	/**
@@ -308,27 +319,33 @@ class condition
 	void optimise(condition_impl *&impl);
 
 	condition_impl *m_impl;
-	bool m_prepared = false;
 };
 
 namespace detail
 {
+	/// @cond
+
 	struct key_is_empty_condition_impl : public condition_impl
 	{
-		key_is_empty_condition_impl(const std::string &item_name)
-			: m_item_name(item_name)
+		key_is_empty_condition_impl(std::string item_name)
+			: m_item_name(std::move(item_name))
 		{
 		}
 
 		condition_impl *prepare(const category &c) override
 		{
-			m_item_ix = get_item_ix(c, m_item_name);
+			auto ix = get_item_ix(c, m_item_name);
+			if (ix.has_value())
+				m_item_ix = *ix;
+			else
+				m_missing_key = true;
+
 			return this;
 		}
 
-		bool test(row_handle r) const override
+		[[nodiscard]] bool test(const_row_handle r) const override
 		{
-			return r[m_item_ix].empty();
+			return m_missing_key or r[m_item_ix].empty();
 		}
 
 		void str(std::ostream &os) const override
@@ -338,22 +355,28 @@ namespace detail
 
 		std::string m_item_name;
 		uint16_t m_item_ix = 0;
+		bool m_missing_key = false;
 	};
 
 	struct key_is_not_empty_condition_impl : public condition_impl
 	{
-		key_is_not_empty_condition_impl(const std::string &item_name)
-			: m_item_name(item_name)
+		key_is_not_empty_condition_impl(std::string item_name)
+			: m_item_name(std::move(item_name))
 		{
 		}
 
 		condition_impl *prepare(const category &c) override
 		{
-			m_item_ix = get_item_ix(c, m_item_name);
-			return this;
+			auto ix = get_item_ix(c, m_item_name);
+			if (ix.has_value())
+			{
+				m_item_ix = *ix;
+				return this;
+			}
+			return nullptr;
 		}
 
-		bool test(row_handle r) const override
+		[[nodiscard]] bool test(const_row_handle r) const override
 		{
 			return not r[m_item_ix].empty();
 		}
@@ -371,13 +394,13 @@ namespace detail
 	{
 		key_equals_condition_impl(item &&i)
 			: m_item_name(i.name())
-			, m_value(std::forward<item>(i).value())
+			, m_value(std::forward<item_value>(i.value()))
 		{
 		}
 
 		condition_impl *prepare(const category &c) override;
 
-		bool test(row_handle r) const override
+		[[nodiscard]] bool test(const_row_handle r) const override
 		{
 			return m_single_hit.has_value() ? *m_single_hit == r : r[m_item_ix].compare(m_value, m_icase) == 0;
 		}
@@ -387,12 +410,12 @@ namespace detail
 			os << m_item_name << (m_icase ? "^ " : " ") << " == " << m_value;
 		}
 
-		virtual std::optional<row_handle> single() const override
+		[[nodiscard]] std::optional<const_row_handle> single() const override
 		{
 			return m_single_hit;
 		}
 
-		virtual bool equals(const condition_impl *rhs) const override
+		bool equals(const condition_impl *rhs) const override
 		{
 			if (typeid(*rhs) == typeid(key_equals_condition_impl))
 			{
@@ -409,8 +432,8 @@ namespace detail
 		std::string m_item_name;
 		uint16_t m_item_ix = 0;
 		bool m_icase = false;
-		std::string m_value;
-		std::optional<row_handle> m_single_hit;
+		item_value m_value;
+		std::optional<const_row_handle> m_single_hit;
 	};
 
 	struct key_equals_or_empty_condition_impl : public condition_impl
@@ -425,18 +448,29 @@ namespace detail
 
 		condition_impl *prepare(const category &c) override
 		{
-			m_item_ix = get_item_ix(c, m_item_name);
-			m_icase = is_item_type_uchar(c, m_item_name);
+			auto ix = get_item_ix(c, m_item_name);
+			if (ix.has_value())
+			{
+				m_item_ix = *ix;
+				m_icase = is_item_type_uchar(c, m_item_name);
+			}
+			else
+				m_key_is_missing = true;
+
 			return this;
 		}
 
-		bool test(row_handle r) const override
+		[[nodiscard]] bool test(const_row_handle r) const override
 		{
 			bool result = false;
-			if (m_single_hit.has_value())
+
+			if (m_key_is_missing)
+				result = true;
+			else if (m_single_hit.has_value())
 				result = *m_single_hit == r;
 			else
 				result = r[m_item_ix].empty() or r[m_item_ix].compare(m_value, m_icase) == 0;
+
 			return result;
 		}
 
@@ -445,12 +479,12 @@ namespace detail
 			os << '(' << m_item_name << (m_icase ? "^ " : " ") << " == " << m_value << " OR " << m_item_name << " IS NULL)";
 		}
 
-		virtual std::optional<row_handle> single() const override
+		[[nodiscard]] std::optional<const_row_handle> single() const override
 		{
 			return m_single_hit;
 		}
 
-		virtual bool equals(const condition_impl *rhs) const override
+		[[nodiscard]] bool equals(const condition_impl *rhs) const override
 		{
 			if (typeid(*rhs) == typeid(key_equals_or_empty_condition_impl))
 			{
@@ -466,129 +500,35 @@ namespace detail
 
 		std::string m_item_name;
 		uint16_t m_item_ix = 0;
-		std::string m_value;
+		item_value m_value;
 		bool m_icase = false;
-		std::optional<row_handle> m_single_hit;
-	};
-
-	struct key_equals_number_condition_impl : public condition_impl
-	{
-		key_equals_number_condition_impl(const std::string &name, double v)
-			: m_item_name(name)
-			, m_value(v)
-		{
-		}
-
-		condition_impl *prepare(const category &c) override;
-
-		bool test(row_handle r) const override
-		{
-			return m_single_hit.has_value() ? *m_single_hit == r : r[m_item_ix].compare(m_value) == 0;
-		}
-
-		void str(std::ostream &os) const override
-		{
-			os << m_item_name << " == " << m_value;
-		}
-
-		virtual std::optional<row_handle> single() const override
-		{
-			return m_single_hit;
-		}
-
-		virtual bool equals(const condition_impl *rhs) const override
-		{
-			if (typeid(*rhs) == typeid(key_equals_number_condition_impl))
-			{
-				auto ri = static_cast<const key_equals_number_condition_impl *>(rhs);
-				if (m_single_hit.has_value() or ri->m_single_hit.has_value())
-					return m_single_hit == ri->m_single_hit;
-				else
-					// watch out, both m_item_ix might be the same while item_names might be diffent (in case they both do not exist in the category)
-					return m_item_ix == ri->m_item_ix and m_value == ri->m_value and m_item_name == ri->m_item_name;
-			}
-			return this == rhs;
-		}
-
-		std::string m_item_name;
-		uint16_t m_item_ix = 0;
-		double m_value;
-		std::optional<row_handle> m_single_hit;
-	};
-
-	struct key_equals_number_or_empty_condition_impl : public condition_impl
-	{
-		key_equals_number_or_empty_condition_impl(key_equals_number_condition_impl *equals)
-			: m_item_name(equals->m_item_name)
-			, m_value(equals->m_value)
-			, m_single_hit(equals->m_single_hit)
-		{
-		}
-
-		condition_impl *prepare(const category &c) override
-		{
-			m_item_ix = get_item_ix(c, m_item_name);
-			return this;
-		}
-
-		bool test(row_handle r) const override
-		{
-			bool result = false;
-			if (m_single_hit.has_value())
-				result = *m_single_hit == r;
-			else
-				result = r[m_item_ix].empty() or r[m_item_ix].compare(m_value) == 0;
-			return result;
-		}
-
-		void str(std::ostream &os) const override
-		{
-			os << '(' << m_item_name << " == " << m_value << " OR " << m_item_name << " IS NULL)";
-		}
-
-		virtual std::optional<row_handle> single() const override
-		{
-			return m_single_hit;
-		}
-
-		virtual bool equals(const condition_impl *rhs) const override
-		{
-			if (typeid(*rhs) == typeid(key_equals_number_or_empty_condition_impl))
-			{
-				auto ri = static_cast<const key_equals_number_or_empty_condition_impl *>(rhs);
-				if (m_single_hit.has_value() or ri->m_single_hit.has_value())
-					return m_single_hit == ri->m_single_hit;
-				else
-					// watch out, both m_item_ix might be the same while item_names might be diffent (in case they both do not exist in the category)
-					return m_item_ix == ri->m_item_ix and m_value == ri->m_value and m_item_name == ri->m_item_name;
-			}
-			return this == rhs;
-		}
-
-		std::string m_item_name;
-		uint16_t m_item_ix = 0;
-		double m_value;
-		std::optional<row_handle> m_single_hit;
+		bool m_key_is_missing = false;
+		std::optional<const_row_handle> m_single_hit;
 	};
 
 	struct key_compare_condition_impl : public condition_impl
 	{
 		template <typename COMP>
-		key_compare_condition_impl(const std::string &item_name, COMP &&comp, const std::string &s)
-			: m_item_name(item_name)
-			, m_compare(std::move(comp))
-			, m_str(s)
+		key_compare_condition_impl(std::string item_name, COMP &&comp, std::string s)
+			: m_item_name(std::move(item_name))
+			, m_compare(std::forward<COMP>(comp))
+			, m_str(std::move(s))
 		{
 		}
 
 		condition_impl *prepare(const category &c) override
 		{
-			m_item_ix = get_item_ix(c, m_item_name);
-			m_icase = is_item_type_uchar(c, m_item_name);
-			return this;
+			auto ix = get_item_ix(c, m_item_name);
+			if (ix.has_value())
+			{
+				m_item_ix = *ix;
+				m_icase = is_item_type_uchar(c, m_item_name);
+				return this;
+			}
+			return nullptr;
 		}
 
-		bool test(row_handle r) const override
+		[[nodiscard]] bool test(const_row_handle r) const override
 		{
 			return m_compare(r, m_icase);
 		}
@@ -601,28 +541,32 @@ namespace detail
 		std::string m_item_name;
 		uint16_t m_item_ix = 0;
 		bool m_icase = false;
-		std::function<bool(row_handle, bool)> m_compare;
+		std::function<bool(const_row_handle, bool)> m_compare;
 		std::string m_str;
 	};
 
 	struct key_matches_condition_impl : public condition_impl
 	{
-		key_matches_condition_impl(const std::string &item_name, const std::regex &rx)
-			: m_item_name(item_name)
-			, m_item_ix(0)
-			, mRx(rx)
+		key_matches_condition_impl(std::string item_name, std::regex rx)
+			: m_item_name(std::move(item_name))
+			, mRx(std::move(rx))
 		{
 		}
 
 		condition_impl *prepare(const category &c) override
 		{
-			m_item_ix = get_item_ix(c, m_item_name);
-			return this;
+			auto ix = get_item_ix(c, m_item_name);
+			if (ix.has_value())
+			{
+				m_item_ix = *ix;
+				return this;
+			}
+			return nullptr;
 		}
 
-		bool test(row_handle r) const override
+		[[nodiscard]] bool test(const_row_handle r) const override
 		{
-			std::string_view txt = r[m_item_ix].text();
+			auto txt = r[m_item_ix].get<std::string>();
 			return std::regex_match(txt.begin(), txt.end(), mRx);
 		}
 
@@ -632,37 +576,31 @@ namespace detail
 		}
 
 		std::string m_item_name;
-		uint16_t m_item_ix;
+		uint16_t m_item_ix{};
 		std::regex mRx;
 	};
 
 	template <typename T>
 	struct any_is_condition_impl : public condition_impl
 	{
-		typedef T valueType;
+		using valueType = T;
 
 		any_is_condition_impl(const valueType &value)
 			: mValue(value)
 		{
 		}
 
-		bool test(row_handle r) const override
+		[[nodiscard]] bool test(const_row_handle r) const override
 		{
 			auto &c = r.get_category();
 
 			bool result = false;
 			for (auto &f : get_category_items(c))
 			{
-				try
-				{
-					if (r[f].compare(mValue) == 0)
-					{
-						result = true;
-						break;
-					}
-				}
-				catch (...)
+				if (r[f].compare(mValue) == 0)
 				{
+					result = true;
+					break;
 				}
 			}
 
@@ -679,12 +617,12 @@ namespace detail
 
 	struct any_matches_condition_impl : public condition_impl
 	{
-		any_matches_condition_impl(const std::regex &rx)
-			: mRx(rx)
+		any_matches_condition_impl(std::regex rx)
+			: mRx(std::move(rx))
 		{
 		}
 
-		bool test(row_handle r) const override
+		[[nodiscard]] bool test(const_row_handle r) const override
 		{
 			auto &c = r.get_category();
 
@@ -693,14 +631,14 @@ namespace detail
 			{
 				try
 				{
-					std::string_view txt = r[f].text();
+					auto txt = r[f].get<std::string>();
 					if (std::regex_match(txt.begin(), txt.end(), mRx))
 					{
 						result = true;
 						break;
 					}
 				}
-				catch (...)
+				catch (const std::exception &ex) // NOLINT(bugprone-empty-catch)
 				{
 				}
 			}
@@ -727,14 +665,14 @@ namespace detail
 		{
 			if (typeid(*a.m_impl) == typeid(*this))
 			{
-				and_condition_impl *ai = static_cast<and_condition_impl *>(a.m_impl);
+				auto *ai = static_cast<and_condition_impl *>(a.m_impl);
 
 				std::swap(m_sub, ai->m_sub);
 				m_sub.emplace_back(std::exchange(b.m_impl, nullptr));
 			}
 			else if (typeid(*b.m_impl) == typeid(*this))
 			{
-				and_condition_impl *bi = static_cast<and_condition_impl *>(b.m_impl);
+				auto *bi = static_cast<and_condition_impl *>(b.m_impl);
 
 				std::swap(m_sub, bi->m_sub);
 				m_sub.emplace_back(std::exchange(a.m_impl, nullptr));
@@ -746,7 +684,7 @@ namespace detail
 			}
 		}
 
-		~and_condition_impl()
+		~and_condition_impl() override // NOLINT(modernize-use-equals-default)
 		{
 			for (auto sub : m_sub)
 				delete sub;
@@ -754,7 +692,7 @@ namespace detail
 
 		condition_impl *prepare(const category &c) override;
 
-		bool test(row_handle r) const override;
+		[[nodiscard]] bool test(const_row_handle r) const override;
 
 		void str(std::ostream &os) const override
 		{
@@ -774,9 +712,9 @@ namespace detail
 			os << ')';
 		}
 
-		virtual std::optional<row_handle> single() const override
+		[[nodiscard]] std::optional<const_row_handle> single() const override
 		{
-			std::optional<row_handle> result;
+			std::optional<const_row_handle> result;
 
 			for (auto sub : m_sub)
 			{
@@ -801,7 +739,7 @@ namespace detail
 		static condition_impl *combine_equal(std::vector<and_condition_impl *> &subs, or_condition_impl *oc);
 
 		std::vector<condition_impl *> m_sub;
-		std::optional<row_handle> m_single; // Potential result of index lookup
+		std::optional<const_row_handle> m_single; // Potential result of index lookup
 	};
 
 	struct or_condition_impl : public condition_impl
@@ -810,14 +748,14 @@ namespace detail
 		{
 			if (typeid(*a.m_impl) == typeid(*this))
 			{
-				or_condition_impl *ai = static_cast<or_condition_impl *>(a.m_impl);
+				auto *ai = static_cast<or_condition_impl *>(a.m_impl);
 
 				std::swap(m_sub, ai->m_sub);
 				m_sub.emplace_back(std::exchange(b.m_impl, nullptr));
 			}
 			else if (typeid(*b.m_impl) == typeid(*this))
 			{
-				or_condition_impl *bi = static_cast<or_condition_impl *>(b.m_impl);
+				auto *bi = static_cast<or_condition_impl *>(b.m_impl);
 
 				std::swap(m_sub, bi->m_sub);
 				m_sub.emplace_back(std::exchange(a.m_impl, nullptr));
@@ -829,7 +767,7 @@ namespace detail
 			}
 		}
 
-		~or_condition_impl()
+		~or_condition_impl() override // NOLINT(modernize-use-equals-default)
 		{
 			for (auto sub : m_sub)
 				delete sub;
@@ -837,7 +775,7 @@ namespace detail
 
 		condition_impl *prepare(const category &c) override;
 
-		bool test(row_handle r) const override
+		[[nodiscard]] bool test(const_row_handle r) const override
 		{
 			bool result = false;
 
@@ -868,9 +806,9 @@ namespace detail
 			os << ')';
 		}
 
-		virtual std::optional<row_handle> single() const override
+		[[nodiscard]] std::optional<const_row_handle> single() const override
 		{
-			std::optional<row_handle> result;
+			std::optional<const_row_handle> result;
 
 			for (auto sub : m_sub)
 			{
@@ -898,23 +836,21 @@ namespace detail
 	struct not_condition_impl : public condition_impl
 	{
 		not_condition_impl(condition &&a)
-			: mA(nullptr)
 		{
 			std::swap(mA, a.m_impl);
 		}
 
-		~not_condition_impl()
+		~not_condition_impl() override
 		{
 			delete mA;
 		}
 
 		condition_impl *prepare(const category &c) override
 		{
-			mA = mA->prepare(c);
-			return this;
+			return mA->prepare(c) ? this : nullptr;
 		}
 
-		bool test(row_handle r) const override
+		[[nodiscard]] bool test(const_row_handle r) const override
 		{
 			return not mA->test(r);
 		}
@@ -926,9 +862,11 @@ namespace detail
 			os << ')';
 		}
 
-		condition_impl *mA;
+		condition_impl *mA = nullptr;
 	};
 
+	/// @endcond
+
 } // namespace detail
 
 /**
@@ -939,8 +877,8 @@ inline condition operator and(condition &&a, condition &&b)
 	if (a.m_impl and b.m_impl)
 		return condition(new detail::and_condition_impl(std::move(a), std::move(b)));
 	if (a.m_impl)
-		return condition(std::move(a));
-	return condition(std::move(b));
+		return a;
+	return b;
 }
 
 /**
@@ -970,33 +908,13 @@ inline condition operator or(condition &&a, condition &&b)
 				return condition(new detail::key_equals_or_empty_condition_impl(ci));
 		}
 
-		if (typeid(*a.m_impl) == typeid(detail::key_equals_number_condition_impl) and
-			typeid(*b.m_impl) == typeid(detail::key_is_empty_condition_impl))
-		{
-			auto ci = static_cast<detail::key_equals_number_condition_impl *>(a.m_impl);
-			auto ce = static_cast<detail::key_is_empty_condition_impl *>(b.m_impl);
-
-			if (ci->m_item_name == ce->m_item_name)
-				return condition(new detail::key_equals_number_or_empty_condition_impl(ci));
-		}
-
-		if (typeid(*b.m_impl) == typeid(detail::key_equals_number_condition_impl) and
-			typeid(*a.m_impl) == typeid(detail::key_is_empty_condition_impl))
-		{
-			auto ci = static_cast<detail::key_equals_number_condition_impl *>(b.m_impl);
-			auto ce = static_cast<detail::key_is_empty_condition_impl *>(a.m_impl);
-
-			if (ci->m_item_name == ce->m_item_name)
-				return condition(new detail::key_equals_number_or_empty_condition_impl(ci));
-		}
-
 		return condition(new detail::or_condition_impl(std::move(a), std::move(b)));
 	}
 
 	if (a.m_impl)
-		return condition(std::move(a));
+		return a;
 
-	return condition(std::move(b));
+	return b;
 }
 
 /**
@@ -1032,8 +950,8 @@ struct key
 	 *
 	 * @param item_name
 	 */
-	explicit key(const std::string &item_name)
-		: m_item_name(item_name)
+	explicit key(std::string item_name)
+		: m_item_name(std::move(item_name))
 	{
 	}
 
@@ -1063,22 +981,14 @@ struct key
 	std::string m_item_name; ///< The item name
 };
 
+/// concept to check for numeric data
 template <typename T>
 concept Numeric = ((std::is_floating_point_v<T> or std::is_integral_v<T>) and not std::is_same_v<T, bool>);
 
-/**
- * @brief Operator to create an equals condition based on a key @a key and a numeric value @a v
- */
-template <Numeric T>
-condition operator==(const key &key, const T &v)
-{
-	return condition(new detail::key_equals_number_condition_impl(key.m_item_name, v));
-}
-
 /**
  * @brief Operator to create an equals condition based on a key @a key and a value @a value
  */
-inline condition operator==(const key &key, std::string_view value)
+inline condition operator==(const key &key, const item_value &value)
 {
 	if (not value.empty())
 		return condition(new detail::key_equals_condition_impl({ key.m_item_name, value }));
@@ -1086,29 +996,10 @@ inline condition operator==(const key &key, std::string_view value)
 		return condition(new detail::key_is_empty_condition_impl(key.m_item_name));
 }
 
-/**
- * @brief Operator to create an equals condition based on a key @a key and a value @a value
- */
-template <typename T>
-	requires std::is_same_v<T, bool>
-inline condition operator==(const key &key, T value)
-{
-	return condition(new detail::key_equals_condition_impl({ key.m_item_name, value ? "y" : "n" }));
-}
-
-/**
- * @brief Operator to create a not equals condition based on a key @a key and a value @a v
- */
-template <typename T>
-condition operator!=(const key &key, const T &v)
-{
-	return condition(new detail::not_condition_impl(operator==(key, v)));
-}
-
 /**
  * @brief Operator to create a not equals condition based on a key @a key and a value @a value
  */
-inline condition operator!=(const key &key, std::string_view value)
+inline condition operator!=(const key &key, const item_value &value)
 {
 	return condition(new detail::not_condition_impl(operator==(key, value)));
 }
@@ -1120,7 +1011,7 @@ template <Numeric T>
 condition operator>(const key &key, const T &v)
 {
 	return condition(new detail::key_compare_condition_impl(
-		key.m_item_name, [item_name = key.m_item_name, v](row_handle r, bool icase)
+		key.m_item_name, [item_name = key.m_item_name, v](const_row_handle r, bool icase)
 		{ return r[item_name].compare(v) > 0; },
 		std::format(" > {}", v)));
 }
@@ -1132,7 +1023,7 @@ template <Numeric T>
 condition operator>=(const key &key, const T &v)
 {
 	return condition(new detail::key_compare_condition_impl(
-		key.m_item_name, [item_name = key.m_item_name, v](row_handle r, bool icase)
+		key.m_item_name, [item_name = key.m_item_name, v](const_row_handle r, bool icase)
 		{ return r[item_name].compare(v) >= 0; },
 		std::format(" >= {}", v)));
 }
@@ -1144,7 +1035,7 @@ template <Numeric T>
 condition operator<(const key &key, const T &v)
 {
 	return condition(new detail::key_compare_condition_impl(
-		key.m_item_name, [item_name = key.m_item_name, v](row_handle r, bool icase)
+		key.m_item_name, [item_name = key.m_item_name, v](const_row_handle r, bool icase)
 		{ return r[item_name].compare(v) < 0; },
 		std::format(" < {}", v)));
 }
@@ -1156,7 +1047,7 @@ template <Numeric T>
 condition operator<=(const key &key, const T &v)
 {
 	return condition(new detail::key_compare_condition_impl(
-		key.m_item_name, [item_name = key.m_item_name, v](row_handle r, bool icase)
+		key.m_item_name, [item_name = key.m_item_name, v](const_row_handle r, bool icase)
 		{ return r[item_name].compare(v) <= 0; },
 		std::format(" <= {}", v)));
 }
@@ -1167,7 +1058,7 @@ condition operator<=(const key &key, const T &v)
 inline condition operator>(const key &key, std::string_view v)
 {
 	return condition(new detail::key_compare_condition_impl(
-		key.m_item_name, [item_name = key.m_item_name, v](row_handle r, bool icase)
+		key.m_item_name, [item_name = key.m_item_name, v](const_row_handle r, bool icase)
 		{ return r[item_name].compare(v, icase) > 0; },
 		std::format(" > {}", v)));
 }
@@ -1178,7 +1069,7 @@ inline condition operator>(const key &key, std::string_view v)
 inline condition operator>=(const key &key, std::string_view v)
 {
 	return condition(new detail::key_compare_condition_impl(
-		key.m_item_name, [item_name = key.m_item_name, v](row_handle r, bool icase)
+		key.m_item_name, [item_name = key.m_item_name, v](const_row_handle r, bool icase)
 		{ return r[item_name].compare(v, icase) >= 0; },
 		std::format(" >= {}", v)));
 }
@@ -1189,7 +1080,7 @@ inline condition operator>=(const key &key, std::string_view v)
 inline condition operator<(const key &key, std::string_view v)
 {
 	return condition(new detail::key_compare_condition_impl(
-		key.m_item_name, [item_name = key.m_item_name, v](row_handle r, bool icase)
+		key.m_item_name, [item_name = key.m_item_name, v](const_row_handle r, bool icase)
 		{ return r[item_name].compare(v, icase) < 0; },
 		std::format(" < {}", v)));
 }
@@ -1200,7 +1091,7 @@ inline condition operator<(const key &key, std::string_view v)
 inline condition operator<=(const key &key, std::string_view v)
 {
 	return condition(new detail::key_compare_condition_impl(
-		key.m_item_name, [item_name = key.m_item_name, v](row_handle r, bool icase)
+		key.m_item_name, [item_name = key.m_item_name, v](const_row_handle r, bool icase)
 		{ return r[item_name].compare(v, icase) <= 0; },
 		std::format(" <= {}", v)));
 }

include/cif++/cql.hpp

@@ -0,0 +1,507 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2025  NKI/AVL, Netherlands Cancer Institute
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+/**
+ * @file cql.hpp
+ *
+ * This file contains code to access stored data as if it were
+ * a relation database. The underlying code uses SQLite as engine.
+ * categories are exposed as virtual tables.
+ */
+
+#include "cif++/category.hpp"
+#include "cif++/item.hpp"
+#include "cif++/iterator.hpp"
+#include "cif++/row.hpp"
+
+#include <cstddef>
+#include <cstdint>
+#include <iterator>
+#include <memory>
+#include <ostream>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <utility>
+
+// --------------------------------------------------------------------
+
+namespace cif::cql
+{
+
+class connection;
+struct result_impl;
+
+// --------------------------------------------------------------------
+
+/// Reference to a field in the result set
+class field_ref final
+{
+  public:
+	/// The name of the field
+	[[nodiscard]] std::string_view name() const &
+	{
+		return m_row.get_category().get_item_name(m_index);
+	}
+
+	/// The index number of the field
+	[[nodiscard]] constexpr size_t num() const noexcept
+	{
+		return m_index;
+	}
+
+	/** Return the contents of this item as type @tparam T */
+	template <typename T = std::string>
+	[[nodiscard]] auto get() const -> T
+	{
+		return m_row[m_index].get<T>();
+	}
+
+	/// Returns true if the field contains NULL
+	[[nodiscard]] bool is_null() const
+	{
+		return m_row[m_index].is_null();
+	}
+
+	/** Return the contents of this item as type @tparam T or, if not
+	 * set, use @a dv as the default value.
+	 */
+	template <typename T>
+	auto value_or(const T &dv) const
+	{
+		return m_row[m_index].value_or(dv);
+	}
+
+	/// Constructor
+	field_ref(const_row_handle rh, uint16_t col, std::shared_ptr<result_impl> result_impl)
+		: m_row(std::move(rh))
+		, m_index(col)
+		, m_result_impl(std::move(result_impl))
+	{
+	}
+
+	/// Copy constructor
+	field_ref(const field_ref &) = default;
+	/// Move constructor
+	field_ref(field_ref &&) = default;
+
+	/// Copy assignment
+	field_ref &operator=(const field_ref &) = default;
+	/// Move assignment
+	field_ref &operator=(field_ref &&) = default;
+
+  private:
+	const_row_handle m_row;
+	uint16_t m_index;
+
+	std::shared_ptr<result_impl> m_result_impl;
+};
+
+// --------------------------------------------------------------------
+
+/// A reference to a row in the result set
+class row_ref final
+{
+  public:
+	/// Iterator for the items in this row
+	class const_field_iterator
+	{
+	  public:
+		friend class result;
+
+		/// @cond
+		using iterator_category = std::forward_iterator_tag;
+		using value_type = const field_ref;
+		using difference_type = std::ptrdiff_t;
+		using pointer = value_type *;
+		using reference = value_type &;
+
+		const_field_iterator(const const_field_iterator &) = default;
+		const_field_iterator(const_field_iterator &&) = default;
+
+		const_field_iterator &operator=(const const_field_iterator &) = default;
+		const_field_iterator &operator=(const_field_iterator &&) = default;
+
+		reference operator*()
+		{
+			return m_current;
+		}
+
+		pointer operator->()
+		{
+			return &m_current;
+		}
+
+		const_field_iterator &operator++()
+		{
+			if (m_row)
+			{
+				++m_col;
+				m_current = field_ref(m_row, m_col, m_result_impl);
+			}
+
+			return *this;
+		}
+
+		const_field_iterator operator++(int)
+		{
+			const_field_iterator result(*this);
+			this->operator++();
+			return result;
+		}
+
+		bool operator==(const const_field_iterator &rhs) const
+		{
+			return m_row == rhs.m_row and m_col == rhs.m_col;
+		}
+
+		bool operator!=(const const_field_iterator &rhs) const
+		{
+			return m_row != rhs.m_row or m_col != rhs.m_col;
+		}
+
+	  private:
+		friend class row_ref;
+
+		const_field_iterator(const_row_handle row, uint16_t column, std::shared_ptr<result_impl> result_impl)
+			: m_row(std::move(row))
+			, m_col(column)
+			, m_current(m_row, m_col, result_impl)
+			, m_result_impl(result_impl)
+		{
+		}
+
+		const_row_handle m_row;
+		uint16_t m_col;
+		field_ref m_current;
+
+		std::shared_ptr<result_impl> m_result_impl;
+
+		/// @endcond
+	};
+
+	// --------------------------------------------------------------------
+
+	row_ref() = default;
+
+	/// Constructor
+	row_ref(const_row_handle rh, std::shared_ptr<result_impl> result_impl)
+		: m_row(std::move(rh))
+		, m_result_impl(std::move(result_impl))
+	{
+	}
+
+	/// @cond
+	row_ref(const row_ref &) = default;
+	row_ref &operator=(const row_ref &) = default;
+	/// @endcond
+
+	// --------------------------------------------------------------------
+
+	[[nodiscard]] const_field_iterator begin() const noexcept { return { m_row, 0, m_result_impl }; }                            ///< Return begin field iterator
+	[[nodiscard]] const_field_iterator cbegin() const noexcept { return { m_row, 0, m_result_impl }; }                           ///< Return cbegin field iterator
+	[[nodiscard]] const_field_iterator end() const noexcept { return { m_row, static_cast<uint16_t>(size()), m_result_impl }; }  ///< Return end field iterator
+	[[nodiscard]] const_field_iterator cend() const noexcept { return { m_row, static_cast<uint16_t>(size()), m_result_impl }; } ///< Return cend field iterator
+
+	[[nodiscard]] field_ref front() const noexcept { return { m_row, 0, m_result_impl }; }                                ///< return reference to front field
+	[[nodiscard]] field_ref back() const noexcept { return { m_row, static_cast<uint16_t>(size() - 1), m_result_impl }; } ///< return reference to back field
+
+	[[nodiscard]] size_t size() const noexcept;                       ///< return number of items in the row
+	[[nodiscard]] bool empty() const noexcept { return size() == 0; } ///< return if the row contains no items at all
+
+	[[nodiscard]] field_ref operator[](uint16_t index) const noexcept { return { m_row, index, m_result_impl }; } ///< access field by index
+	[[nodiscard]] field_ref operator[](std::string_view name) const;                                              ///< access field by name
+
+	// --------------------------------------------------------------------
+
+	/// @cond
+	bool operator==(const row_ref &rhs) const { return m_row == rhs.m_row; }
+	bool operator!=(const row_ref &rhs) const { return m_row != rhs.m_row; }
+
+  private:
+	const_row_handle m_row;
+	std::shared_ptr<result_impl> m_result_impl;
+
+	/// @endcond
+};
+
+// --------------------------------------------------------------------
+
+/// The result set, containing the result of a query
+class result
+{
+  public:
+	// --------------------------------------------------------------------
+
+	/// iterator to the rows in the result set
+	class iterator
+	{
+	  public:
+		friend class view;
+
+		/// @cond
+
+		using iterator_category = std::forward_iterator_tag;
+		using value_type = const row_ref;
+		using difference_type = std::ptrdiff_t;
+		using pointer = value_type *;
+		using reference = value_type &;
+
+		// const_row_iterator() = default;
+
+		iterator(std::shared_ptr<result_impl> result_impl, category::const_iterator cat_iter)
+			: m_iter(std::move(cat_iter))
+			, m_current(*m_iter, result_impl)
+			, m_result_impl(result_impl)
+		{
+		}
+
+		iterator(const iterator &) = default;
+		iterator(iterator &&) = default;
+
+		// const_row_iterator &operator=(const const_row_iterator &) = default;
+		// const_row_iterator &operator=(const_row_iterator &&) = default;
+
+		reference operator*()
+		{
+			return m_current;
+		}
+
+		pointer operator->()
+		{
+			return &m_current;
+		}
+
+		iterator &operator++()
+		{
+			++m_iter;
+			m_current = { *m_iter, m_result_impl };
+			return *this;
+		}
+
+		iterator operator++(int)
+		{
+			iterator result(*this);
+			this->operator++();
+			return result;
+		}
+
+		bool operator==(const iterator &rhs) const
+		{
+			return m_result_impl == rhs.m_result_impl and m_iter == rhs.m_iter;
+		}
+
+		bool operator!=(const iterator &rhs) const
+		{
+			return m_result_impl != rhs.m_result_impl or m_iter != rhs.m_iter;
+		}
+
+	  private:
+		category::const_iterator m_iter;
+		row_ref m_current;
+		std::shared_ptr<result_impl> m_result_impl;
+
+		/// @endcond
+	};
+
+	// --------------------------------------------------------------------
+
+	/// @cond
+	result() = delete;
+	result(result const &rhs) noexcept = default;
+	result(result &&rhs) noexcept = default;
+	result &operator=(result const &rhs) noexcept = default;
+	result &operator=(result &&rhs) noexcept = default;
+
+	result(category &&data, const std::string &query = "");
+
+	~result() = default;
+	/// @endcond
+
+	/// Return the row if and only if the result set contains exactly one row, throws otherwise
+	[[nodiscard]] row_ref one_row() const
+	{
+		if (size() != 1)
+			throw std::runtime_error("Expected one row");
+		return front();
+	}
+
+	/// Return the row if and only if the result set contains exactly one row,
+	/// and this row also contains only one field, throws otherwise
+	[[nodiscard]] field_ref one_field() const
+	{
+		expect_columns(1);
+
+		if (size() != 1)
+			throw std::runtime_error("Expected one row");
+
+		return one_row().front();
+	}
+
+	// --------------------------------------------------------------------
+
+	/// @cond
+	[[nodiscard]] iterator begin() const noexcept;
+	[[nodiscard]] iterator cbegin() const noexcept;
+
+	[[nodiscard]] iterator end() const noexcept;
+	[[nodiscard]] iterator cend() const noexcept;
+
+	[[nodiscard]] row_ref front() const;
+	[[nodiscard]] row_ref back() const;
+
+	[[nodiscard]] size_t size() const noexcept;
+	[[nodiscard]] bool empty() const noexcept { return size() == 0; }
+	/// @endcond
+
+	/// Return the number of colums/fields in each row
+	[[nodiscard]] size_t column_count() const;
+
+	/// Return the result set as a cif::category
+	[[nodiscard]] category &get_category() const;
+
+	/// Test to see if the result set contains at least the number of fields/columns
+	/// but only when not empty
+	void expect_columns(size_t cols) const
+	{
+		if (auto actual = column_count(); size() > 0 and cols != actual)
+			throw std::runtime_error("Unexpected number of columns");
+	}
+
+	// --------------------------------------------------------------------
+
+	/// Print out the result set, for debugging mostly
+	friend std::ostream &operator<<(std::ostream &os, const result &r)
+	{
+		os << r.get_category();
+		return os;
+	}
+
+  private:
+	friend class transaction;
+	friend class SelectStatement;
+
+	std::shared_ptr<result_impl> m_impl;
+};
+
+// --------------------------------------------------------------------
+
+/// Helper class to allow access to the data as a stream
+template <typename... Ts>
+class cql_iterator_proxy : public cif::iterator_proxy<Ts...>
+{
+  public:
+	/// Constructor
+	cql_iterator_proxy(result &&res)
+		: cif::iterator_proxy<Ts...>(res.get_category())
+		, m_result(std::forward<result>(res))
+	{
+		m_result.expect_columns(cif::iterator_proxy<Ts...>::N);
+	}
+
+  private:
+	result m_result;
+};
+
+// --------------------------------------------------------------------
+
+/// Transaction class.
+/// At construction, this class starts a transaction on the connection
+/// and at exit an automatic rollback is done, unless commit was called.
+class transaction final
+{
+  public:
+    /// Constructor
+	transaction(connection &conn);
+
+	/// @cond
+	~transaction();
+
+	transaction(const transaction &) = delete;
+	transaction &operator=(const transaction &) = delete;
+	/// @endcond
+
+	/// \brief Execute the sql in @a query returning an iterable result
+	result exec(std::string query);
+
+	/// \brief Execute the sql in @a query returning an iterable result.
+	/// Updates @a tail with what remains after the first statement in @a query
+	result exec(std::string query, std::string &tail);
+
+	/// Execute the sql in @a sql and return the result as a stream
+	template <typename... Ts>
+	cql_iterator_proxy<Ts...> stream(const std::string &sql)
+	{
+		return cql_iterator_proxy<Ts...>{ exec(sql) };
+	}
+
+	/// Commit the result of the operations
+	void commit();
+
+	/// Rollback the result of the operations, the underlying data is
+	/// restored to the state before the construction of this transaction.
+	void rollback();
+
+  private:
+	connection &m_conn;
+	bool m_transaction_active = false;
+};
+
+// --------------------------------------------------------------------
+
+/// This connection class creates a SQLite environment with the data in
+/// the provided datablock as tables.
+class connection final
+{
+  public:
+	/// Constructor
+	connection(datablock &db);
+
+	/// Destructor
+	~connection();
+
+	friend class transaction;
+
+	/// \brief Return true if the string @a sql contains a complete statement.
+	[[nodiscard]] bool is_complete_statement(const std::string &sql) const;
+
+	/// \brief Execute the sql in @a query returning an iterable result
+	result exec(std::string query);
+
+	/// \brief Execute the sql in @a query returning an iterable result.
+	/// Updates @a tail with what remains after the first statement in @a query
+	result exec(std::string query, std::string &tail);
+
+	/// \brief Return true if the underlying data was modified by any query.
+	[[nodiscard]] bool is_modified() const;
+
+  private:
+	struct connection_impl *m_impl;
+};
+
+} // namespace cif::cql

include/cif++/datablock.hpp

@@ -27,9 +27,14 @@
 #pragma once
 
 #include "cif++/category.hpp"
-#include "cif++/forward_decl.hpp"
 
+#include <iosfwd>
 #include <list>
+#include <string>
+#include <string_view>
+#include <tuple>
+#include <utility>
+#include <vector>
 
 /** \file datablock.hpp
  * Each valid mmCIF file contains at least one @ref cif::datablock.
@@ -39,11 +44,13 @@
 namespace cif
 {
 
+class validator;
+
 // --------------------------------------------------------------------
 
 /**
  * @brief A datablock is a list of category objects with some additional features
- * 
+ *
  */
 
 class datablock : public std::list<category>
@@ -53,7 +60,7 @@ class datablock : public std::list<category>
 
 	/**
 	 * @brief Construct a new datablock object with name @a name
-	 * 
+	 *
 	 * @param name The name for the new datablock
 	 */
 	datablock(std::string_view name)
@@ -76,11 +83,12 @@ class datablock : public std::list<category>
 	}
 	/** @endcond */
 
+	/// Swap two datablocks
 	friend void swap_(datablock &a, datablock &b) noexcept
 	{
 		std::swap(a.m_name, b.m_name);
 		std::swap(a.m_validator, b.m_validator);
-		std::swap(static_cast<std::list<category>&>(a), static_cast<std::list<category>&>(b));
+		std::swap(static_cast<std::list<category> &>(a), static_cast<std::list<category> &>(b));
 	}
 
 	// --------------------------------------------------------------------
@@ -88,11 +96,11 @@ class datablock : public std::list<category>
 	/**
 	 * @brief Return the name of this datablock
 	 */
-	const std::string &name() const { return m_name; }
+	[[nodiscard]] const std::string &name() const { return m_name; }
 
 	/**
 	 * @brief Set the name of this datablock to @a name
-	 * 
+	 *
 	 * @param name The new name
 	 */
 	void set_name(std::string_view name)
@@ -102,45 +110,51 @@ class datablock : public std::list<category>
 
 	/**
 	 * @brief Attempt to load the dictionary specified in audit_conform category
-	 * 
+	 *
 	 */
 	void load_dictionary();
 
+	/**
+	 * @brief Attempt to load the dictionary @a dict
+	 *
+	 */
+	void load_dictionary(std::string_view dict);
+
 	/**
 	 * @brief Set the validator object to @a v
-	 * 
+	 *
 	 * @param v The new validator object, may be null
 	 */
 	void set_validator(const validator *v);
 
 	/**
 	 * @brief Get the validator object
-	 * 
+	 *
 	 * @return const validator* The validator or nullptr if there is none
 	 */
-	const validator *get_validator() const;
+	[[nodiscard]] const validator *get_validator() const;
 
 	/**
 	 * @brief Validates the content of this datablock and all its content
-	 * 
+	 *
 	 * @return true If the content is valid
 	 * @return false If the content is not valid
 	 */
-	bool is_valid() const;
+	[[nodiscard]] bool is_valid() const;
 
 	/**
 	 * @brief Validates all contained data for valid links between parents and children
 	 * as defined in the validator
-	 * 
+	 *
 	 * @return true If all links are valid
 	 * @return false If all links are not valid
 	 */
-	bool validate_links() const;
+	[[nodiscard]] bool validate_links() const;
 
 	/**
 	 * @brief Strip removes all categories and items that are invalid according
 	 * to the assigned validator. Will also add a valid audit_conform block.
-	 * 
+	 *
 	 * @return true if the remaining datablock is valid
 	 */
 	bool strip();
@@ -150,7 +164,7 @@ class datablock : public std::list<category>
 	/**
 	 * @brief Return the category named @a name, will create a new and empty
 	 * category named @a name if it does not exist.
-	 * 
+	 *
 	 * @param name The name of the category to return
 	 * @return category& Reference to the named category
 	 */
@@ -159,7 +173,7 @@ class datablock : public std::list<category>
 	/**
 	 * @brief Return the const category named @a name, will return a reference
 	 * to a static empty category if it was not found.
-	 * 
+	 *
 	 * @param name The name of the category to return
 	 * @return category& Reference to the named category
 	 */
@@ -168,7 +182,7 @@ class datablock : public std::list<category>
 	/**
 	 * @brief Return a pointer to the category named @a name or nullptr if
 	 * it does not exist.
-	 * 
+	 *
 	 * @param name The name of the category
 	 * @return category* Pointer to the category found or nullptr
 	 */
@@ -177,17 +191,16 @@ class datablock : public std::list<category>
 	/**
 	 * @brief Return a pointer to the category named @a name or nullptr if
 	 * it does not exist.
-	 * 
+	 *
 	 * @param name The name of the category
 	 * @return category* Pointer to the category found or nullptr
 	 */
-	const category *get(std::string_view name) const;
-
+	[[nodiscard]] const category *get(std::string_view name) const;
 
 	/**
 	 * @brief Return true if this datablock contains a non-empty category
 	 */
-	bool contains(std::string_view name) const
+	[[nodiscard]] bool contains(std::string_view name) const
 	{
 		return get(name) != nullptr;
 	}
@@ -197,7 +210,7 @@ class datablock : public std::list<category>
 	 * new one if it is not found. The result is a tuple of an iterator
 	 * pointing to the category and a boolean indicating whether the category
 	 * was created or not.
-	 * 
+	 *
 	 * @param name The name for the category
 	 * @return std::tuple<iterator, bool> A tuple containing an iterator pointing
 	 * at the category and a boolean indicating whether the category was newly
@@ -208,16 +221,7 @@ class datablock : public std::list<category>
 	/**
 	 * @brief Get the preferred order of the categories when writing them
 	 */
-	[[deprecated("use get_item_order instead")]]
-	std::vector<std::string> get_tag_order() const
-	{
-		return get_item_order();
-	}
-
-	/**
-	 * @brief Get the preferred order of the categories when writing them
-	 */
-	std::vector<std::string> get_item_order() const;
+	[[nodiscard]] std::vector<std::string> get_item_order() const;
 
 	/**
 	 * @brief Write out the contents to @a os

include/cif++/dictionary_parser.hpp

@@ -27,6 +27,7 @@
 #pragma once
 
 #include "cif++/validate.hpp"
+#include <iosfwd>
 
 /**
  * @file validate.hpp
@@ -37,6 +38,8 @@
 namespace cif
 {
 
+class validator;
+
 /**
  * @brief Parse the contents of @a is and place content in validator @a v
  */

include/cif++/file.hpp

@@ -26,21 +26,26 @@
 
 #pragma once
 
-#include <list>
-
 #include "cif++/datablock.hpp"
-#include "cif++/parser.hpp"
+
+#include <cassert>
+#include <cstddef>
+#include <filesystem>
+#include <istream>
+#include <list>
+#include <string_view>
+#include <tuple>
 
 /** \file file.hpp
- * 
+ *
  * The file class defined here encapsulates the contents of an mmCIF file
  * It is mainly a list of @ref cif::datablock objects
- * 
+ *
  * The class file has methods to load dictionaries. These dictionaries are
  * loaded from resources (if available) or from disk from several locations.
- * 
+ *
  * See the documentation on load_resource() in file: utilities.hpp for more
- * information on how data is loaded. 
+ * information on how data is loaded.
  */
 
 namespace cif
@@ -50,7 +55,7 @@ namespace cif
 
 /**
  * @brief The class file is actually a list of datablock objects
- * 
+ *
  */
 
 class file : public std::list<datablock>
@@ -60,7 +65,7 @@ class file : public std::list<datablock>
 
 	/**
 	 * @brief Construct a new file object using the data in the file @a p as content
-	 * 
+	 *
 	 * @param p Path to a file containing the data to load
 	 */
 	explicit file(const std::filesystem::path &p)
@@ -70,7 +75,7 @@ class file : public std::list<datablock>
 
 	/**
 	 * @brief Construct a new file object using the data in the std::istream @a is
-	 * 
+	 *
 	 * @param is The istream containing the data to load
 	 */
 	explicit file(std::istream &is)
@@ -81,7 +86,7 @@ class file : public std::list<datablock>
 	/**
 	 * @brief Construct a new file object with data in the constant string defined
 	 * by @a data and @a length
-	 * 
+	 *
 	 * @param data The pointer to the character string with data to load
 	 * @param length The length of the data
 	 */
@@ -100,7 +105,7 @@ class file : public std::list<datablock>
 	}
 
 	/** @cond */
-	file(const file &rhs)
+	file(const file &rhs) // NOLINT
 		: std::list<datablock>(rhs)
 	{
 	}
@@ -120,23 +125,23 @@ class file : public std::list<datablock>
 
 	/**
 	 * @brief Validate the content and return true if everything was valid.
-	 * 
+	 *
 	 * Will throw an exception if there is no validator defined.
-	 * 
+	 *
 	 * If each category was valid, validate_links will also be called.
-	 * 
+	 *
 	 * @return true If the content is valid
 	 * @return false If the content is not valid
 	 */
-	bool is_valid() const;
+	[[nodiscard]] bool is_valid() const;
 
 	/**
 	 * @brief Validate the content and return true if everything was valid.
-	 * 
+	 *
 	 * Will attempt to load the referenced dictionary if none was specified.
-	 * 
+	 *
 	 * If each category was valid, validate_links will also be called.
-	 * 
+	 *
 	 * @return true If the content is valid
 	 * @return false If the content is not valid
 	 */
@@ -144,18 +149,18 @@ class file : public std::list<datablock>
 
 	/**
 	 * @brief Validate the links for all datablocks contained.
-	 * 
+	 *
 	 * Will throw an exception if no validator was specified.
-	 * 
+	 *
 	 * @return true If all links were valid
 	 * @return false If all links were not valid
 	 */
-	bool validate_links() const;
+	[[nodiscard]] bool validate_links() const;
 
 	/**
 	 * @brief Return true if a datablock with the name @a name is part of this file
 	 */
-	bool contains(std::string_view name) const;
+	[[nodiscard]] bool contains(std::string_view name) const;
 
 	/**
 	 * @brief return a reference to the first datablock in the file
@@ -169,7 +174,7 @@ class file : public std::list<datablock>
 	/**
 	 * @brief return a const reference to the first datablock in the file
 	 */
-	const datablock &front() const
+	[[nodiscard]] const datablock &front() const
 	{
 		assert(not empty());
 		return std::list<datablock>::front();
@@ -190,7 +195,7 @@ class file : public std::list<datablock>
 	 * new one if it is not found. The result is a tuple of an iterator
 	 * pointing to the datablock and a boolean indicating whether the datablock
 	 * was created or not.
-	 * 
+	 *
 	 * @param name The name for the datablock
 	 * @return std::tuple<iterator, bool> A tuple containing an iterator pointing
 	 * at the datablock and a boolean indicating whether the datablock was newly
@@ -204,12 +209,6 @@ class file : public std::list<datablock>
 	/** Load the data from @a is */
 	void load(std::istream &is);
 
-	/** Load the data from the file specified by @a p using validator @a v */
-	void load(const std::filesystem::path &p, const validator &v);
-
-	/** Load the data from @a is using validator @a v */
-	void load(std::istream &is, const validator &v);
-
 	/** Save the data to the file specified by @a p */
 	void save(const std::filesystem::path &p) const;
 

include/cif++/format.hpp

@@ -26,8 +26,9 @@
 
 #pragma once
 
-#include <format>
-#include <string>
+#include <ostream>
+#include <streambuf>
+
 
 /**  \file format.hpp
  * 
@@ -66,7 +67,7 @@ class fill_out_streambuf : public std::streambuf
 
 	/** @cond */
 
-	~fill_out_streambuf()
+	~fill_out_streambuf() override
 	{
 		m_os.rdbuf(m_upstream);
 	}
@@ -79,8 +80,7 @@ class fill_out_streambuf : public std::streambuf
 	 * wide as the requested width.
 	 */
 	
-	virtual int_type
-	overflow(int_type ic = traits_type::eof())
+	int_type overflow(int_type ic = traits_type::eof()) override
 	{
 		char ch = traits_type::to_char_type(ic);
 
@@ -110,10 +110,10 @@ class fill_out_streambuf : public std::streambuf
 	}
 
 	/** Return the upstream streambuf */
-	std::streambuf *get_upstream() const { return m_upstream; }
+	[[nodiscard]] std::streambuf *get_upstream() const { return m_upstream; }
 
 	/** Return how many lines have been written */
-	int get_line_count() const { return m_line_count; }
+	[[nodiscard]] int get_line_count() const { return m_line_count; }
 
   private:
 	std::ostream &m_os;

include/cif++/gzio.hpp

@@ -209,7 +209,7 @@ class basic_igzip_streambuf : public basic_streambuf<CharT, Traits>
 		return *this;
 	}
 
-	~basic_igzip_streambuf()
+	~basic_igzip_streambuf() override
 	{
 		close();
 	}
@@ -245,8 +245,8 @@ class basic_igzip_streambuf : public basic_streambuf<CharT, Traits>
 
 		close();
 
-		m_zstream.reset(new z_stream_s);
-		m_gzheader.reset(new gz_header_s);
+		m_zstream = std::make_unique<z_stream_s>();
+		m_gzheader = std::make_unique<gz_header_s>();
 
 		auto &zstream = *m_zstream.get();
 		zstream = z_stream_s{};
@@ -396,7 +396,7 @@ class basic_ogzip_streambuf : public basic_streambuf<CharT, Traits>
 		return *this;
 	}
 
-	~basic_ogzip_streambuf()
+	~basic_ogzip_streambuf() override
 	{
 		close();
 	}
@@ -431,8 +431,8 @@ class basic_ogzip_streambuf : public basic_streambuf<CharT, Traits>
 
 		close();
 
-		m_zstream.reset(new z_stream_s);
-		m_gzheader.reset(new gz_header_s);
+		m_zstream = std::make_unique<z_stream_s>();
+		m_gzheader = std::make_unique<gz_header_s>();
 
 		auto &zstream = *m_zstream.get();
 		zstream = z_stream_s{};
@@ -658,7 +658,7 @@ class basic_ifstream : public basic_istream<CharT, Traits>
 	/// \brief Default constructor, does not open a file since none is specified
 	basic_ifstream() = default;
 
-	~basic_ifstream()
+	~basic_ifstream() override
 	{
 		close();
 	}
@@ -774,7 +774,7 @@ class basic_ifstream : public basic_istream<CharT, Traits>
 	/// \brief Return true if the file is open
 	/// \return m_filebuf.is_open()
 
-	bool is_open() const
+	[[nodiscard]] bool is_open() const
 	{
 		return m_filebuf.is_open();
 	}
@@ -922,7 +922,7 @@ class basic_ofstream : public basic_ostream<CharT, Traits>
 
 	basic_ofstream() = default;
 
-	~basic_ofstream()
+	~basic_ofstream() override
 	{
 		close();
 	}
@@ -1054,7 +1054,7 @@ class basic_ofstream : public basic_ostream<CharT, Traits>
 	/// \brief Return true if the file is open
 	/// \return m_filebuf.is_open()
 
-	bool is_open() const
+	[[nodiscard]] bool is_open() const
 	{
 		return m_filebuf.is_open();
 	}

include/cif++/iterator.hpp

@@ -26,9 +26,13 @@
 
 #pragma once
 
+#include "cif++/condition.hpp"
 #include "cif++/row.hpp"
 
 #include <array>
+#include <cstdint>
+#include <numeric>
+#include <type_traits>
 
 /**
  * @file iterator.hpp
@@ -44,6 +48,8 @@
 namespace cif
 {
 
+class category;
+
 // --------------------------------------------------------------------
 
 /**
@@ -55,13 +61,13 @@ namespace cif
  * @tparam Category The category for this iterator
  * @tparam Ts The types this iterator can be dereferenced to
  */
-template <typename Category, typename... Ts>
-class iterator_impl
+template <bool Const, typename... Ts>
+class iterator_impl_base
 {
   public:
 	/** @cond */
-	template <typename, typename...>
-	friend class iterator_impl;
+	template <bool, typename...>
+	friend class iterator_impl_base;
 
 	friend class category;
 	/** @endcond */
@@ -70,48 +76,47 @@ class iterator_impl
 	static constexpr std::size_t N = sizeof...(Ts);
 
 	/** @cond */
-	using category_type = std::remove_cv_t<Category>;
-	using row_type = std::conditional_t<std::is_const_v<Category>, const row, row>;
-
 	using tuple_type = std::tuple<Ts...>;
 
+	using row_handle_type = std::conditional_t<Const, const_row_handle, row_handle>;
+
 	using iterator_category = std::forward_iterator_tag;
-	using value_type = tuple_type;
+	using value_type = std::conditional_t<Const, const tuple_type, tuple_type>;
 	using difference_type = std::ptrdiff_t;
 	using pointer = value_type *;
 	using reference = value_type &;
 
-	iterator_impl() = default;
+	iterator_impl_base() = default;
 
-	iterator_impl(const iterator_impl &rhs) = default;
-	iterator_impl(iterator_impl &&rhs) = default;
+	iterator_impl_base(const iterator_impl_base &rhs) = default;
+	iterator_impl_base(iterator_impl_base &&rhs) = default;
 
-	template <typename C2, typename... T2s>
-	iterator_impl(const iterator_impl<C2, T2s...> &rhs)
-		: m_current(const_cast<row_handle&>(rhs.m_current))
+	template <bool C, typename... T2s>
+	iterator_impl_base(const iterator_impl_base<C, T2s...> &rhs)
+		: m_current(rhs.m_current)
 		, m_value(rhs.m_value)
 		, m_item_ix(rhs.m_item_ix)
 	{
 	}
 
-	template <typename IRowType>
-	iterator_impl(iterator_impl<IRowType, Ts...> &rhs)
-		: m_current(const_cast<row_handle&>(rhs.m_current))
+	template <bool C>
+	iterator_impl_base(iterator_impl_base<C, Ts...> &rhs)
+		: m_current(rhs.m_current)
 		, m_value(rhs.m_value)
 		, m_item_ix(rhs.m_item_ix)
 	{
 		m_value = get(std::make_index_sequence<N>());
 	}
 
-	template <typename IRowType>
-	iterator_impl(const iterator_impl<IRowType> &rhs, const std::array<uint16_t, N> &cix)
-		: m_current(const_cast<row_handle&>(rhs.m_current))
+	template <bool C>
+	iterator_impl_base(const iterator_impl_base<C> &rhs, const std::array<uint16_t, N> &cix)
+		: m_current(rhs.m_current)
 		, m_item_ix(cix)
 	{
 		m_value = get(std::make_index_sequence<N>());
 	}
 
-	iterator_impl &operator=(iterator_impl i)
+	iterator_impl_base &operator=(iterator_impl_base i)
 	{
 		std::swap(m_current, i.m_current);
 		std::swap(m_item_ix, i.m_item_ix);
@@ -119,29 +124,39 @@ class iterator_impl
 		return *this;
 	}
 
-	virtual ~iterator_impl() = default;
+	virtual ~iterator_impl_base() = default;
 
-	reference operator*()
+	auto operator*()
 	{
 		return m_value;
 	}
 
-	pointer operator->()
+	auto operator*() const
+	{
+		return m_value;
+	}
+
+	auto operator->()
 	{
 		return &m_value;
 	}
 
-	operator const row_handle() const
+	auto operator->() const
+	{
+		return &m_value;
+	}
+
+	operator const_row_handle() const
 	{
 		return m_current;
 	}
 
-	operator row_handle()
+	operator row_handle_type()
 	{
 		return m_current;
 	}
 
-	iterator_impl &operator++()
+	iterator_impl_base &operator++()
 	{
 		if (m_current)
 			m_current.m_row = m_current.m_row->m_next;
@@ -151,24 +166,24 @@ class iterator_impl
 		return *this;
 	}
 
-	iterator_impl operator++(int)
+	iterator_impl_base operator++(int)
 	{
-		iterator_impl result(*this);
+		iterator_impl_base result(*this);
 		this->operator++();
 		return result;
 	}
 
-	bool operator==(const iterator_impl &rhs) const { return m_current == rhs.m_current; }
-	bool operator!=(const iterator_impl &rhs) const { return m_current != rhs.m_current; }
+	bool operator==(const iterator_impl_base &rhs) const { return m_current == rhs.m_current; }
+	bool operator!=(const iterator_impl_base &rhs) const { return m_current != rhs.m_current; }
 
-	template <typename IRowType, typename... ITs>
-	bool operator==(const iterator_impl<IRowType, ITs...> &rhs) const
+	template <bool C, typename... ITs>
+	bool operator==(const iterator_impl_base<C, ITs...> &rhs) const
 	{
 		return m_current == rhs.m_current;
 	}
 
-	template <typename IRowType, typename... ITs>
-	bool operator!=(const iterator_impl<IRowType, ITs...> &rhs) const
+	template <bool C, typename... ITs>
+	bool operator!=(const iterator_impl_base<C, ITs...> &rhs) const
 	{
 		return m_current != rhs.m_current;
 	}
@@ -177,13 +192,13 @@ class iterator_impl
 
   private:
 	template <std::size_t... Is>
-	tuple_type get(std::index_sequence<Is...>) const
+	[[nodiscard]] tuple_type get(std::index_sequence<Is...>) const
 	{
-		return m_current ? tuple_type{ m_current[m_item_ix[Is]].template as<Ts>()... } : tuple_type{};
+		return m_current ? tuple_type{ m_current[m_item_ix[Is]].template get<Ts>()... } : tuple_type{};
 	}
 
-	row_handle m_current;
-	value_type m_value;
+	row_handle_type m_current;
+	tuple_type m_value;
 	std::array<uint16_t, N> m_item_ix;
 };
 
@@ -193,76 +208,94 @@ class iterator_impl
  *
  * @tparam Category The category for this iterator
  */
-template <typename Category>
-class iterator_impl<Category>
+template <bool Const>
+class iterator_impl_base<Const>
 {
   public:
 	/** @cond */
 
-	template <typename, typename...>
-	friend class iterator_impl;
+	template <bool, typename...>
+	friend class iterator_impl_base;
 
 	friend class category;
-	using category_type = std::remove_cv_t<Category>;
-	using row_type = std::conditional_t<std::is_const_v<Category>, const row, row>;
+
+	using category_type = std::conditional_t<Const, const category, category>;
+	using row_type = std::conditional_t<Const, const row, row>;
+	using row_handle_type = std::conditional_t<Const, const_row_handle, row_handle>;
 
 	using iterator_category = std::forward_iterator_tag;
-	using value_type = row_handle;
+
+	using value_type = std::conditional_t<Const, const_row_handle, row_handle>;
 	using difference_type = std::ptrdiff_t;
 	using pointer = value_type *;
 	using reference = value_type &;
 
-	iterator_impl() = default;
+	iterator_impl_base() = default;
 
-	iterator_impl(const iterator_impl &rhs) = default;
-	iterator_impl(iterator_impl &&rhs) = default;
+	iterator_impl_base(const iterator_impl_base &rhs) = default;
+	iterator_impl_base(iterator_impl_base &&rhs) = default;
 
-	template <typename C2>
-	iterator_impl(const iterator_impl<C2> &rhs)
-		: m_current(const_cast<row_handle &>(rhs.m_current))
+	template <bool C>
+	iterator_impl_base(const iterator_impl_base<C> &rhs)
+		: m_current(rhs.m_current)
 	{
 	}
 
-	iterator_impl(Category &cat, row *current)
-		: m_current(cat, *current)
+	iterator_impl_base(const category_type &cat, const row_type *current)
+		: m_current(const_cast<category &>(cat), const_cast<row_type &>(*current))
 	{
 	}
 
-	template <typename IRowType>
-	iterator_impl(const iterator_impl<IRowType> &rhs, const std::array<uint16_t, 0> &)
-		: m_current(const_cast<row_handle &>(rhs.m_current))
+	template <bool C>
+	iterator_impl_base(const iterator_impl_base<C> &rhs, const std::array<uint16_t, 0> &)
+		: m_current(rhs.m_current)
 	{
 	}
 
-	iterator_impl &operator=(iterator_impl i)
+	iterator_impl_base &operator=(iterator_impl_base i)
 	{
 		std::swap(m_current, i.m_current);
 		return *this;
 	}
 
-	virtual ~iterator_impl() = default;
+	virtual ~iterator_impl_base() = default;
 
-	reference operator*()
+	auto operator*()
 	{
 		return m_current;
 	}
 
-	pointer operator->()
+	auto operator*() const
+	{
+		return m_current;
+	}
+
+	auto operator->()
 	{
 		return &m_current;
 	}
 
-	operator const row_handle() const
+	auto operator->() const
+	{
+		return &m_current;
+	}
+
+	operator const_row_handle() const
 	{
 		return m_current;
 	}
 
-	operator row_handle()
+	operator row_handle_type()
 	{
 		return m_current;
 	}
 
-	iterator_impl &operator++()
+	[[nodiscard]] int64_t row_id() const
+	{
+		return reinterpret_cast<int64_t>(m_current.m_row);
+	}
+
+	iterator_impl_base &operator++()
 	{
 		if (m_current)
 			m_current.m_row = m_current.m_row->m_next;
@@ -270,24 +303,24 @@ class iterator_impl<Category>
 		return *this;
 	}
 
-	iterator_impl operator++(int)
+	iterator_impl_base operator++(int)
 	{
-		iterator_impl result(*this);
+		iterator_impl_base result(*this);
 		this->operator++();
 		return result;
 	}
 
-	bool operator==(const iterator_impl &rhs) const { return m_current == rhs.m_current; }
-	bool operator!=(const iterator_impl &rhs) const { return m_current != rhs.m_current; }
+	bool operator==(const iterator_impl_base &rhs) const { return m_current == rhs.m_current; }
+	bool operator!=(const iterator_impl_base &rhs) const { return m_current != rhs.m_current; }
 
-	template <typename IRowType, typename... ITs>
-	bool operator==(const iterator_impl<IRowType, ITs...> &rhs) const
+	template <bool C, typename... ITs>
+	bool operator==(const iterator_impl_base<C, ITs...> &rhs) const
 	{
 		return m_current == rhs.m_current;
 	}
 
-	template <typename IRowType, typename... ITs>
-	bool operator!=(const iterator_impl<IRowType, ITs...> &rhs) const
+	template <bool C, typename... ITs>
+	bool operator!=(const iterator_impl_base<C, ITs...> &rhs) const
 	{
 		return m_current != rhs.m_current;
 	}
@@ -295,7 +328,7 @@ class iterator_impl<Category>
 	/** @endcond */
 
   private:
-	row_handle m_current;
+	row_handle_type m_current;
 };
 
 /**
@@ -306,18 +339,18 @@ class iterator_impl<Category>
  * @tparam T The type this iterator can be dereferenced to
  */
 
-template <typename Category, typename T>
-class iterator_impl<Category, T>
+template <bool Const, typename T>
+class iterator_impl_base<Const, T>
 {
   public:
 	/** @cond */
-	template <typename, typename...>
-	friend class iterator_impl;
+	template <bool, typename...>
+	friend class iterator_impl_base;
 
 	friend class category;
 
-	using category_type = std::remove_cv_t<Category>;
-	using row_type = std::conditional_t<std::is_const_v<Category>, const row, row>;
+	using category_type = std::conditional_t<Const, const category, category>;
+	using row_handle_type = std::conditional_t<Const, const_row_handle, row_handle>;
 
 	using iterator_category = std::forward_iterator_tag;
 	using value_type = T;
@@ -325,37 +358,37 @@ class iterator_impl<Category, T>
 	using pointer = value_type *;
 	using reference = value_type &;
 
-	iterator_impl() = default;
+	iterator_impl_base() = default;
 
-	iterator_impl(const iterator_impl &rhs) = default;
-	iterator_impl(iterator_impl &&rhs) = default;
+	iterator_impl_base(const iterator_impl_base &rhs) = default;
+	iterator_impl_base(iterator_impl_base &&rhs) = default;
 
-	template <typename C2, typename T2>
-	iterator_impl(const iterator_impl<C2, T2> &rhs)
+	template <bool C, typename T2>
+	iterator_impl_base(const iterator_impl_base<C, T2> &rhs)
 		: m_current(rhs.m_current)
 		, m_value(rhs.m_value)
 		, m_item_ix(rhs.m_item_ix)
 	{
 	}
 
-	template <typename IRowType>
-	iterator_impl(iterator_impl<IRowType, T> &rhs)
-		: m_current(const_cast<row_handle&>(rhs.m_current))
+	template <bool C>
+	iterator_impl_base(iterator_impl_base<C, T> &rhs)
+		: m_current(rhs.m_current)
 		, m_value(rhs.m_value)
 		, m_item_ix(rhs.m_item_ix)
 	{
 		m_value = get();
 	}
 
-	template <typename IRowType>
-	iterator_impl(const iterator_impl<IRowType> &rhs, const std::array<uint16_t, 1> &cix)
-		: m_current(const_cast<row_handle&>(rhs.m_current))
+	template <bool C>
+	iterator_impl_base(const iterator_impl_base<C> &rhs, const std::array<uint16_t, 1> &cix)
+		: m_current(rhs.m_current)
 		, m_item_ix(cix[0])
 	{
 		m_value = get();
 	}
 
-	iterator_impl &operator=(iterator_impl i)
+	iterator_impl_base &operator=(iterator_impl_base i)
 	{
 		std::swap(m_current, i.m_current);
 		std::swap(m_item_ix, i.m_item_ix);
@@ -363,29 +396,39 @@ class iterator_impl<Category, T>
 		return *this;
 	}
 
-	virtual ~iterator_impl() = default;
+	virtual ~iterator_impl_base() = default;
 
-	reference operator*()
+	auto operator*()
 	{
 		return m_value;
 	}
 
-	pointer operator->()
+	auto operator*() const
+	{
+		return m_value;
+	}
+
+	auto operator->()
 	{
 		return &m_value;
 	}
 
-	operator const row_handle() const
+	auto operator->() const
+	{
+		return &m_value;
+	}
+
+	operator const_row_handle() const
 	{
 		return m_current;
 	}
 
-	operator row_handle()
+	operator row_handle_type()
 	{
 		return m_current;
 	}
 
-	iterator_impl &operator++()
+	iterator_impl_base &operator++()
 	{
 		if (m_current)
 			m_current.m_row = m_current.m_row->m_next;
@@ -395,24 +438,24 @@ class iterator_impl<Category, T>
 		return *this;
 	}
 
-	iterator_impl operator++(int)
+	iterator_impl_base operator++(int)
 	{
-		iterator_impl result(*this);
+		iterator_impl_base result(*this);
 		this->operator++();
 		return result;
 	}
 
-	bool operator==(const iterator_impl &rhs) const { return m_current == rhs.m_current; }
-	bool operator!=(const iterator_impl &rhs) const { return m_current != rhs.m_current; }
+	bool operator==(const iterator_impl_base &rhs) const { return m_current == rhs.m_current; }
+	bool operator!=(const iterator_impl_base &rhs) const { return m_current != rhs.m_current; }
 
-	template <typename IRowType, typename... ITs>
-	bool operator==(const iterator_impl<IRowType, ITs...> &rhs) const
+	template <bool C, typename... ITs>
+	bool operator==(const iterator_impl_base<C, ITs...> &rhs) const
 	{
 		return m_current == rhs.m_current;
 	}
 
-	template <typename IRowType, typename... ITs>
-	bool operator!=(const iterator_impl<IRowType, ITs...> &rhs) const
+	template <bool C, typename... ITs>
+	bool operator!=(const iterator_impl_base<C, ITs...> &rhs) const
 	{
 		return m_current != rhs.m_current;
 	}
@@ -420,16 +463,26 @@ class iterator_impl<Category, T>
 	/** @endcond */
 
   private:
-	value_type get() const
+	[[nodiscard]] value_type get() const
 	{
-		return m_current ?  m_current[m_item_ix].template as<value_type>() : value_type{};
+		return m_current ?  m_current[m_item_ix].template get<value_type>() : value_type{};
 	}
 
-	row_handle m_current;
+	row_handle_type m_current;
 	value_type m_value;
 	uint16_t m_item_ix;
 };
 
+// --------------------------------------------------------------------
+
+/// A non-const version of iterator_impl
+template<typename ... Ts>
+using iterator_impl = iterator_impl_base<false, Ts...>;
+
+/// A const version of iterator_impl
+template<typename ... Ts>
+using const_iterator_impl = iterator_impl_base<true, Ts...>;
+
 // --------------------------------------------------------------------
 // iterator proxy
 
@@ -445,43 +498,42 @@ class iterator_impl<Category, T>
  * @tparam Ts The types the iterators return. See class: iterator
  */
 
-template <typename Category, typename... Ts>
-class iterator_proxy
+template <bool Const, typename... Ts>
+class iterator_proxy_base
 {
   public:
 	/** @cond */
 	static constexpr const std::size_t N = sizeof...(Ts);
 
-	using category_type = Category;
-	using row_type = std::conditional_t<std::is_const_v<category_type>, const row, row>;
+	using category_type = std::conditional_t<Const, const category, category>;
 
-	using iterator = iterator_impl<category_type, Ts...>;
-	using row_iterator = iterator_impl<category_type>;
+	using iterator = iterator_impl_base<Const, Ts...>;
+	using row_iterator = iterator_impl_base<Const>;
 
-	iterator_proxy(category_type &cat, row_iterator pos, char const *const items[N]);
-	iterator_proxy(category_type &cat, row_iterator pos, std::initializer_list<char const *> items);
+	iterator_proxy_base(category_type &cat, row_iterator pos, char const *const items[N]);
+	iterator_proxy_base(category_type &cat, row_iterator pos, std::initializer_list<char const *> items); // NOLINT(modernize-pass-by-value)
 
-	iterator_proxy(iterator_proxy &&p);
-	iterator_proxy &operator=(iterator_proxy &&p);
+	iterator_proxy_base(iterator_proxy_base &&p);
+	iterator_proxy_base &operator=(iterator_proxy_base &&p);
 
-	iterator_proxy(const iterator_proxy &) = delete;
-	iterator_proxy &operator=(const iterator_proxy &) = delete;
+	iterator_proxy_base(const iterator_proxy_base &) = delete;
+	iterator_proxy_base &operator=(const iterator_proxy_base &) = delete;
 	/** @endcond */
 
-	iterator begin() const { return iterator(m_begin, m_item_ix); } ///< Return the iterator pointing to the first row
-	iterator end() const { return iterator(m_end, m_item_ix); }     ///< Return the iterator pointing past the last row
+	[[nodiscard]] iterator begin() const { return iterator(m_begin, m_item_ix); } ///< Return the iterator pointing to the first row
+	[[nodiscard]] iterator end() const { return iterator(m_end, m_item_ix); }     ///< Return the iterator pointing past the last row
 
-	bool empty() const { return m_begin == m_end; }               ///< Return true if the range is empty
+	[[nodiscard]] bool empty() const { return m_begin == m_end; }               ///< Return true if the range is empty
 	explicit operator bool() const { return not empty(); }        ///< Easy way to detect if the range is empty
-	std::size_t size() const { return std::distance(begin(), end()); } ///< Return size of the range
+	[[nodiscard]] std::size_t size() const { return std::distance(begin(), end()); } ///< Return size of the range
 
 	// row front() { return *begin(); }
 	// row back() { return *(std::prev(end())); }
 
-	category_type &category() const { return *m_category; } ///< Return the category the iterator belong to
+	[[nodiscard]] category_type &get_category() const { return *m_category; } ///< Return the category the iterator belong to
 
 	/** swap */
-	void swap(iterator_proxy &rhs)
+	void swap(iterator_proxy_base &rhs)
 	{
 		std::swap(m_category, rhs.m_category);
 		std::swap(m_begin, rhs.m_begin);
@@ -489,12 +541,27 @@ class iterator_proxy
 		std::swap(m_item_ix, rhs.m_item_ix);
 	}
 
+  protected:
+	/// @cond
+	iterator_proxy_base(category_type &cat);
+	/// @endcond
+
   private:
 	category_type *m_category;
 	row_iterator m_begin, m_end;
 	std::array<uint16_t, N> m_item_ix;
 };
 
+// --------------------------------------------------------------------
+
+/// A non-const version of iterator_proxy_base
+template <typename... Ts>
+using iterator_proxy = iterator_proxy_base<false, Ts...>;
+
+/// A const version of iterator_proxy_base
+template <typename... Ts>
+using const_iterator_proxy = iterator_proxy_base<true, Ts...>;
+
 // --------------------------------------------------------------------
 // conditional iterator proxy
 
@@ -504,44 +571,54 @@ class iterator_proxy
  * In the case of an conditional_iterator_proxy a cif::condition is used
  * to filter out only those rows that match the condition.
  *
- * @tparam CategoryType The category the iterators belong to
+ * @tparam category_type The category the iterators belong to
  * @tparam Ts The types to which the iterators can be dereferenced
  */
-template <typename CategoryType, typename... Ts>
-class conditional_iterator_proxy
+template <bool Const, typename... Ts>
+class conditional_iterator_proxy_base
 {
   public:
 	/** @cond */
 	static constexpr const std::size_t N = sizeof...(Ts);
 
-	using category_type = std::remove_cv_t<CategoryType>;
-
-	using base_iterator = iterator_impl<CategoryType, Ts...>;
+	using category_type = std::conditional_t<Const, const category, category>;
+	using base_iterator = iterator_impl_base<Const, Ts...>;
 	using value_type = typename base_iterator::value_type;
-	using row_type = typename base_iterator::row_type;
-	using row_iterator = iterator_impl<CategoryType>;
+	using row_iterator = iterator_impl_base<Const>;
 
 	class conditional_iterator_impl
 	{
 	  public:
 		using iterator_category = std::forward_iterator_tag;
-		using value_type = conditional_iterator_proxy::value_type;
+		using value_type = conditional_iterator_proxy_base::value_type;
 		using difference_type = std::ptrdiff_t;
 		using pointer = value_type *;
 		using reference = value_type;
 
-		conditional_iterator_impl(CategoryType &cat, row_iterator pos, const condition &cond, const std::array<uint16_t, N> &cix);
+		conditional_iterator_impl() = default;
+		conditional_iterator_impl(category_type &cat, row_iterator pos, const condition &cond, const std::array<uint16_t, N> &cix);
 		conditional_iterator_impl(const conditional_iterator_impl &i) = default;
 		conditional_iterator_impl &operator=(const conditional_iterator_impl &i) = default;
 
 		virtual ~conditional_iterator_impl() = default;
 
-		reference operator*()
+		auto operator*()
 		{
 			return *m_begin;
 		}
 
-		pointer operator->()
+		auto operator*() const
+		{
+			return *m_begin;
+		}
+
+		auto operator->()
+		{
+			m_current = *m_begin;
+			return &m_current;
+		}
+
+		auto operator->() const
 		{
 			m_current = *m_begin;
 			return &m_current;
@@ -574,16 +651,16 @@ class conditional_iterator_proxy
 		bool operator==(const row_iterator &rhs) const { return m_begin == rhs; }
 		bool operator!=(const row_iterator &rhs) const { return m_begin != rhs; }
 
-		template <typename IRowType, typename... ITs>
-		bool operator==(const iterator_impl<IRowType, ITs...> &rhs) const { return m_begin == rhs; }
+		template <bool C, typename... ITs>
+		bool operator==(const iterator_impl_base<C, ITs...> &rhs) const { return m_begin == rhs; }
 
-		template <typename IRowType, typename... ITs>
-		bool operator!=(const iterator_impl<IRowType, ITs...> &rhs) const { return m_begin != rhs; }
+		template <bool C, typename... ITs>
+		bool operator!=(const iterator_impl_base<C, ITs...> &rhs) const { return m_begin != rhs; }
 
 	  private:
-		CategoryType *m_cat;
+		category_type *m_cat = nullptr;
 		base_iterator m_begin, m_end;
-		value_type m_current;
+		std::remove_cv_t<value_type> m_current;
 		const condition *m_condition;
 	};
 
@@ -591,33 +668,42 @@ class conditional_iterator_proxy
 	using reference = typename iterator::reference;
 
 	template <typename... Ns>
-	conditional_iterator_proxy(CategoryType &cat, row_iterator pos, condition &&cond, Ns... names);
+	conditional_iterator_proxy_base(category_type &cat, row_iterator pos, condition &&cond, Ns... names); // NOLINT(modernize-pass-by-value)
 
-	conditional_iterator_proxy(conditional_iterator_proxy &&p);
-	conditional_iterator_proxy &operator=(conditional_iterator_proxy &&p);
+	conditional_iterator_proxy_base(conditional_iterator_proxy_base &&p)
+	{
+		swap(*this, p);
+	}
 
-	conditional_iterator_proxy(const conditional_iterator_proxy &) = delete;
-	conditional_iterator_proxy &operator=(const conditional_iterator_proxy &) = delete;
+	conditional_iterator_proxy_base &operator=(conditional_iterator_proxy_base &&p)
+	{
+		swap(*this, p);
+		return *this;
+	}
+
+	conditional_iterator_proxy_base(const conditional_iterator_proxy_base &) = delete;
+	conditional_iterator_proxy_base &operator=(const conditional_iterator_proxy_base &) = delete;
 
 	/** @endcond */
 
-	iterator begin() const; ///< Return the iterator pointing to the first row
-	iterator end() const;   ///< Return the iterator pointing past the last row
+	[[nodiscard]] iterator begin() const; ///< Return the iterator pointing to the first row
+	[[nodiscard]] iterator end() const;   ///< Return the iterator pointing past the last row
 
-	bool empty() const;                                           ///< Return true if the range is empty
+	[[nodiscard]] bool empty() const;                                           ///< Return true if the range is empty
 	explicit operator bool() const { return not empty(); }        ///< Easy way to detect if the range is empty
-	std::size_t size() const { return std::distance(begin(), end()); } ///< Return size of the range
+	[[nodiscard]] std::size_t size() const { return std::distance(begin(), end()); } ///< Return size of the range
 
-	row_handle front() { return *begin(); } ///< Return reference to the first row
+	auto front() { return *begin(); } ///< Return reference to the first row
 	// row_handle back() { return *begin(); }
 
-	CategoryType &category() const { return *m_cat; } ///< Category the iterators belong to
+	[[nodiscard]] category_type &get_category() const { return *m_cat; } ///< Category the iterators belong to
 
 	/** swap */
-	void swap(conditional_iterator_proxy &rhs);
+	template <bool C2, typename ... T2s>
+	friend void swap(conditional_iterator_proxy_base<C2, T2s...> &lhs, conditional_iterator_proxy_base<C2, T2s...> &rhs);
 
   private:
-	CategoryType *m_cat;
+	category_type *m_cat;
 	condition m_condition;
 	row_iterator mCBegin, mCEnd;
 	std::array<uint16_t, N> mCix;
@@ -625,9 +711,19 @@ class conditional_iterator_proxy
 
 // --------------------------------------------------------------------
 
+/// A non-const version of conditional_iterator_proxy_base
+template <typename... Ts>
+using conditional_iterator_proxy = conditional_iterator_proxy_base<false, Ts...>;
+
+/// A const version of conditional_iterator_proxy_base
+template <typename... Ts>
+using const_conditional_iterator_proxy = conditional_iterator_proxy_base<true, Ts...>;
+
+// --------------------------------------------------------------------
+
 /** @cond */
-template <typename Category, typename... Ts>
-iterator_proxy<Category, Ts...>::iterator_proxy(Category &cat, row_iterator pos, char const *const items[N])
+template <bool Const, typename... Ts>
+iterator_proxy_base<Const, Ts...>::iterator_proxy_base(category_type &cat, row_iterator pos, char const *const items[N])
 	: m_category(&cat)
 	, m_begin(pos)
 	, m_end(cat.end())
@@ -636,8 +732,8 @@ iterator_proxy<Category, Ts...>::iterator_proxy(Category &cat, row_iterator pos,
 		m_item_ix[i] = m_category->get_item_ix(items[i]);
 }
 
-template <typename Category, typename... Ts>
-iterator_proxy<Category, Ts...>::iterator_proxy(Category &cat, row_iterator pos, std::initializer_list<char const *> items)
+template <bool Const, typename... Ts>
+iterator_proxy_base<Const, Ts...>::iterator_proxy_base(category_type &cat, row_iterator pos, std::initializer_list<char const *> items)
 	: m_category(&cat)
 	, m_begin(pos)
 	, m_end(cat.end())
@@ -649,11 +745,20 @@ iterator_proxy<Category, Ts...>::iterator_proxy(Category &cat, row_iterator pos,
 		m_item_ix[i++] = m_category->get_item_ix(item);
 }
 
+template <bool Const, typename... Ts>
+iterator_proxy_base<Const, Ts...>::iterator_proxy_base(category_type &cat)
+	: m_category(&cat)
+	, m_begin(cat.begin())
+	, m_end(cat.end())
+{
+	std::iota(m_item_ix.begin(), m_item_ix.end(), 0);
+}
+
 // --------------------------------------------------------------------
 
-template <typename Category, typename... Ts>
-conditional_iterator_proxy<Category, Ts...>::conditional_iterator_impl::conditional_iterator_impl(
-	Category &cat, row_iterator pos, const condition &cond, const std::array<uint16_t, N> &cix)
+template <bool Const, typename... Ts>
+conditional_iterator_proxy_base<Const, Ts...>::conditional_iterator_impl::conditional_iterator_impl(
+	category_type &cat, row_iterator pos, const condition &cond, const std::array<uint16_t, N> &cix)
 	: m_cat(&cat)
 	, m_begin(pos, cix)
 	, m_end(cat.end(), cix)
@@ -661,23 +766,13 @@ conditional_iterator_proxy<Category, Ts...>::conditional_iterator_impl::conditio
 {
 	if (m_condition == nullptr or m_condition->empty())
 		m_begin = m_end;
+	else
+		m_current = *m_begin;
 }
 
-template <typename Category, typename... Ts>
-conditional_iterator_proxy<Category, Ts...>::conditional_iterator_proxy(conditional_iterator_proxy &&p)
-	: m_cat(nullptr)
-	, mCBegin(p.mCBegin)
-	, mCEnd(p.mCEnd)
-	, mCix(p.mCix)
-{
-	std::swap(m_cat, p.m_cat);
-	std::swap(mCix, p.mCix);
-	m_condition.swap(p.m_condition);
-}
-
-template <typename Category, typename... Ts>
+template <bool Const, typename... Ts>
 template <typename... Ns>
-conditional_iterator_proxy<Category, Ts...>::conditional_iterator_proxy(Category &cat, row_iterator pos, condition &&cond, Ns... names)
+conditional_iterator_proxy_base<Const, Ts...>::conditional_iterator_proxy_base(category_type &cat, row_iterator pos, condition &&cond, Ns... names)
 	: m_cat(&cat)
 	, m_condition(std::move(cond))
 	, mCBegin(pos)
@@ -685,10 +780,8 @@ conditional_iterator_proxy<Category, Ts...>::conditional_iterator_proxy(Category
 {
 	static_assert(sizeof...(Ts) == sizeof...(Ns), "Number of item names should be equal to number of requested value types");
 
-	if (m_condition)
+	if (m_condition and m_condition.prepare(cat))
 	{
-		m_condition.prepare(cat);
-
 		while (mCBegin != mCEnd and not m_condition(*mCBegin))
 			++mCBegin;
 	}
@@ -699,41 +792,39 @@ conditional_iterator_proxy<Category, Ts...>::conditional_iterator_proxy(Category
 	((mCix[i++] = m_cat->get_item_ix(names)), ...);
 }
 
-template <typename Category, typename... Ts>
-conditional_iterator_proxy<Category, Ts...> &conditional_iterator_proxy<Category, Ts...>::operator=(conditional_iterator_proxy &&p)
+template <bool Const, typename... Ts>
+auto conditional_iterator_proxy_base<Const, Ts...>::begin() const -> iterator
 {
-	swap(p);
-	return *this;
+	return iterator{ *m_cat, mCBegin, m_condition, mCix };
 }
 
-template <typename Category, typename... Ts>
-typename conditional_iterator_proxy<Category, Ts...>::iterator conditional_iterator_proxy<Category, Ts...>::begin() const
+template <bool Const, typename... Ts>
+auto conditional_iterator_proxy_base<Const, Ts...>::end() const -> iterator
 {
-	return iterator(*m_cat, mCBegin, m_condition, mCix);
+	return iterator{ *m_cat, mCEnd, m_condition, mCix };
 }
 
-template <typename Category, typename... Ts>
-typename conditional_iterator_proxy<Category, Ts...>::iterator conditional_iterator_proxy<Category, Ts...>::end() const
-{
-	return iterator(*m_cat, mCEnd, m_condition, mCix);
-}
-
-template <typename Category, typename... Ts>
-bool conditional_iterator_proxy<Category, Ts...>::empty() const
+template <bool Const, typename... Ts>
+bool conditional_iterator_proxy_base<Const, Ts...>::empty() const
 {
 	return mCBegin == mCEnd;
 }
 
-template <typename Category, typename... Ts>
-void conditional_iterator_proxy<Category, Ts...>::swap(conditional_iterator_proxy &rhs)
+template <bool Const, typename... Ts>
+void swap(conditional_iterator_proxy_base<Const, Ts...> &lhs, conditional_iterator_proxy_base<Const, Ts...> &rhs)
 {
-	std::swap(m_cat, rhs.m_cat);
-	m_condition.swap(rhs.m_condition);
-	std::swap(mCBegin, rhs.mCBegin);
-	std::swap(mCEnd, rhs.mCEnd);
-	std::swap(mCix, rhs.mCix);
+	std::swap(lhs.m_cat, rhs.m_cat);
+	std::swap(lhs.m_condition, rhs.m_condition);
+	std::swap(lhs.mCBegin, rhs.mCBegin);
+	std::swap(lhs.mCEnd, rhs.mCEnd);
+	std::swap(lhs.mCix, rhs.mCix);
 }
 
+// --------------------------------------------------------------------
+
+// template <bool Const, typename... Ts>
+
+
 /** @endcond */
 
-} // namespace cif
+} // namespace cif

include/cif++/matrix.hpp

@@ -29,19 +29,17 @@
 #include <array>
 #include <cassert>
 #include <cmath>
-#include <cstdint>
 #include <ostream>
-#include <tuple>
 #include <type_traits>
 #include <vector>
 
 /**
  * @file matrix.hpp
- * 
+ *
  * Some basic matrix operations and classes to hold matrices.
- * 
+ *
  * We're using expression templates for optimal performance.
- * 
+ *
  */
 
 namespace cif
@@ -52,26 +50,26 @@ namespace cif
 /**
  * @brief Base for the matrix expression templates
  * This all uses the Curiously recurring template pattern
- * 
+ *
  * @tparam M The type of the derived class
  */
 template <typename M>
-class matrix_expression
+class matrix_expression // NOLINT(bugprone-crtp-constructor-accessibility)
 {
   public:
-	constexpr std::size_t dim_m() const { return static_cast<const M &>(*this).dim_m(); } ///< Return the size (dimension) in direction m
-	constexpr std::size_t dim_n() const { return static_cast<const M &>(*this).dim_n(); } ///< Return the size (dimension) in direction n
+	[[nodiscard]] constexpr std::size_t dim_m() const { return static_cast<const M &>(*this).dim_m(); } ///< Return the size (dimension) in direction m
+	[[nodiscard]] constexpr std::size_t dim_n() const { return static_cast<const M &>(*this).dim_n(); } ///< Return the size (dimension) in direction n
 
-	constexpr bool empty() const { return dim_m() == 0 or dim_n() == 0; } ///< Convenient way to test for empty matrices
+	[[nodiscard]] constexpr bool empty() const { return dim_m() == 0 or dim_n() == 0; } ///< Convenient way to test for empty matrices
 
 	/** Return a reference to element [ @a i, @a j ] */
-	constexpr auto &operator()(std::size_t i, std::size_t j)
+	[[nodiscard]] constexpr auto &operator()(std::size_t i, std::size_t j)
 	{
 		return static_cast<M &>(*this).operator()(i, j);
 	}
 
 	/** Return the value of element [ @a i, @a j ] */
-	constexpr auto operator()(std::size_t i, std::size_t j) const
+	[[nodiscard]] constexpr auto operator()(std::size_t i, std::size_t j) const
 	{
 		return static_cast<const M &>(*this).operator()(i, j);
 	}
@@ -124,15 +122,33 @@ class matrix_expression
 
 		return os;
 	}
+
+	/// compare two matrices
+	template <typename M2>
+	constexpr bool operator==(const matrix_expression<M2> &m) const
+	{
+		bool same = false;
+		if (dim_m() == m.dim_m() and dim_n() == m.dim_n())
+		{
+			same = true;
+			for (std::size_t i = 0; same and i < m.dim_m(); ++i)
+			{
+				for (std::size_t j = 0; same and j < m.dim_n(); ++j)
+					same = operator()(i, j) == m(i, j);
+			}
+		}
+
+		return same;
+	}
 };
 
 // --------------------------------------------------------------------
 
 /**
  * @brief Storage class implementation of matrix_expression.
- * 
+ *
  * @tparam F The type of the stored values
- *  
+ *
  * matrix is m x n, addressing i,j is 0 <= i < m and 0 <= j < n
  * element m i,j is mapped to [i * n + j] and thus storage is row major
  */
@@ -146,7 +162,7 @@ class matrix : public matrix_expression<matrix<F>>
 
 	/**
 	 * @brief Copy construct a new matrix object using @a m
-	 * 
+	 *
 	 * @tparam M2 Type of @a m
 	 * @param m The matrix expression to copy values from
 	 */
@@ -166,7 +182,7 @@ class matrix : public matrix_expression<matrix<F>>
 	/**
 	 * @brief Construct a new matrix object with dimension @a m and @a n
 	 * setting the values to @a v
-	 * 
+	 *
 	 * @param m Requested dimension M
 	 * @param n Requested dimension N
 	 * @param v Value to store in each element
@@ -187,11 +203,11 @@ class matrix : public matrix_expression<matrix<F>>
 	matrix &operator=(const matrix &m) = default;
 	/** @endcond */
 
-	constexpr std::size_t dim_m() const { return m_m; } ///< Return dimension m
-	constexpr std::size_t dim_n() const { return m_n; } ///< Return dimension n
+	[[nodiscard]] constexpr std::size_t dim_m() const { return m_m; } ///< Return dimension m
+	[[nodiscard]] constexpr std::size_t dim_n() const { return m_n; } ///< Return dimension n
 
 	/** Return the value of element [ @a i, @a j ] */
-	constexpr value_type operator()(std::size_t i, std::size_t j) const
+	[[nodiscard]] constexpr value_type operator()(std::size_t i, std::size_t j) const
 	{
 		assert(i < m_m);
 		assert(j < m_n);
@@ -199,7 +215,7 @@ class matrix : public matrix_expression<matrix<F>>
 	}
 
 	/** Return a reference to element [ @a i, @a j ] */
-	constexpr value_type &operator()(std::size_t i, std::size_t j)
+	[[nodiscard]] constexpr value_type &operator()(std::size_t i, std::size_t j)
 	{
 		assert(i < m_m);
 		assert(j < m_n);
@@ -217,9 +233,9 @@ class matrix : public matrix_expression<matrix<F>>
 /**
  * @brief Storage class implementation of matrix_expression
  * with compile time fixed size.
- * 
+ *
  * @tparam F The type of the stored values
- *  
+ *
  * matrix is m x n, addressing i,j is 0 <= i < m and 0 <= j < n
  * element m i,j is mapped to [i * n + j] and thus storage is row major
  */
@@ -266,18 +282,18 @@ class matrix_fixed : public matrix_expression<matrix_fixed<F, M, N>>
 	/** @endcond */
 
 	/** Store the values in @a a in the matrix */
-	template<std::size_t... Ixs>
-	matrix_fixed& fill(const F (&a)[kSize], std::index_sequence<Ixs...>)
+	template <std::size_t... Ixs>
+	matrix_fixed &fill(const F (&a)[kSize], std::index_sequence<Ixs...>)
 	{
 		m_data = { a[Ixs]... };
 		return *this;
 	}
 
-	constexpr std::size_t dim_m() const { return M; } ///< Return dimension m
-	constexpr std::size_t dim_n() const { return N; } ///< Return dimension n
+	[[nodiscard]] constexpr std::size_t dim_m() const { return M; } ///< Return dimension m
+	[[nodiscard]] constexpr std::size_t dim_n() const { return N; } ///< Return dimension n
 
 	/** Return the value of element [ @a i, @a j ] */
-	constexpr value_type operator()(std::size_t i, std::size_t j) const
+	[[nodiscard]] constexpr value_type operator()(std::size_t i, std::size_t j) const
 	{
 		assert(i < M);
 		assert(j < N);
@@ -285,7 +301,7 @@ class matrix_fixed : public matrix_expression<matrix_fixed<F, M, N>>
 	}
 
 	/** Return a reference to element [ @a i, @a j ] */
-	constexpr value_type &operator()(std::size_t i, std::size_t j)
+	[[nodiscard]] constexpr value_type &operator()(std::size_t i, std::size_t j)
 	{
 		assert(i < M);
 		assert(j < N);
@@ -308,9 +324,9 @@ using matrix4x4 = matrix_fixed<F, 4, 4>;
 
 /**
  * @brief Storage class implementation of symmetric matrix_expression
- * 
+ *
  * @tparam F The type of the stored values
- *  
+ *
  * matrix is m x n, addressing i,j is 0 <= i < m and 0 <= j < n
  * element m i,j is mapped to [i * n + j] and thus storage is row major
  */
@@ -337,11 +353,11 @@ class symmetric_matrix : public matrix_expression<symmetric_matrix<F>>
 	symmetric_matrix &operator=(const symmetric_matrix &m) = default;
 	/** @endcond */
 
-	constexpr std::size_t dim_m() const { return m_n; } ///< Return dimension m
-	constexpr std::size_t dim_n() const { return m_n; } ///< Return dimension n
+	[[nodiscard]] constexpr std::size_t dim_m() const { return m_n; } ///< Return dimension m
+	[[nodiscard]] constexpr std::size_t dim_n() const { return m_n; } ///< Return dimension n
 
 	/** Return the value of element [ @a i, @a j ] */
-	constexpr value_type operator()(std::size_t i, std::size_t j) const
+	[[nodiscard]] constexpr value_type operator()(std::size_t i, std::size_t j) const
 	{
 		return i < j
 		           ? m_data[(j * (j + 1)) / 2 + i]
@@ -349,7 +365,7 @@ class symmetric_matrix : public matrix_expression<symmetric_matrix<F>>
 	}
 
 	/** Return a reference to element [ @a i, @a j ] */
-	constexpr value_type &operator()(std::size_t i, std::size_t j)
+	[[nodiscard]] constexpr value_type &operator()(std::size_t i, std::size_t j)
 	{
 		if (i > j)
 			std::swap(i, j);
@@ -367,9 +383,9 @@ class symmetric_matrix : public matrix_expression<symmetric_matrix<F>>
 /**
  * @brief Storage class implementation of symmetric matrix_expression
  * with compile time fixed size.
- * 
+ *
  * @tparam F The type of the stored values
- *  
+ *
  * matrix is m x n, addressing i,j is 0 <= i < m and 0 <= j < n
  * element m i,j is mapped to [i * n + j] and thus storage is row major
  */
@@ -393,11 +409,11 @@ class symmetric_matrix_fixed : public matrix_expression<symmetric_matrix_fixed<F
 	symmetric_matrix_fixed &operator=(const symmetric_matrix_fixed &m) = default;
 	/** @endcond */
 
-	constexpr std::size_t dim_m() const { return M; } ///< Return dimension m
-	constexpr std::size_t dim_n() const { return M; } ///< Return dimension n
+	[[nodiscard]] constexpr std::size_t dim_m() const { return M; } ///< Return dimension m
+	[[nodiscard]] constexpr std::size_t dim_n() const { return M; } ///< Return dimension n
 
 	/** Return the value of element [ @a i, @a j ] */
-	constexpr value_type operator()(std::size_t i, std::size_t j) const
+	[[nodiscard]] constexpr value_type operator()(std::size_t i, std::size_t j) const
 	{
 		return i < j
 		           ? m_data[(j * (j + 1)) / 2 + i]
@@ -405,7 +421,7 @@ class symmetric_matrix_fixed : public matrix_expression<symmetric_matrix_fixed<F
 	}
 
 	/** Return a reference to element [ @a i, @a j ] */
-	constexpr value_type &operator()(std::size_t i, std::size_t j)
+	[[nodiscard]] constexpr value_type &operator()(std::size_t i, std::size_t j)
 	{
 		if (i > j)
 			std::swap(i, j);
@@ -427,12 +443,38 @@ using symmetric_matrix4x4 = symmetric_matrix_fixed<F, 4>;
 
 // --------------------------------------------------------------------
 
+/// A transposed matrix view
+
+template <typename M>
+class transposed_matrix : public cif::matrix_expression<transposed_matrix<M>>
+{
+  public:
+	transposed_matrix(const M &m)
+		: m_m(m)
+	{
+	}
+
+	[[nodiscard]] constexpr std::size_t dim_m() const { return m_m.dim_n(); } ///< Return dimension m
+	[[nodiscard]] constexpr std::size_t dim_n() const { return m_m.dim_m(); } ///< Return dimension n
+
+	/** Access to the value of element [ @a i, @a j ] */
+	[[nodiscard]] constexpr auto operator()(std::size_t i, std::size_t j) const
+	{
+		return m_m(j, i);
+	}
+
+  private:
+	const M &m_m;
+};
+
+// --------------------------------------------------------------------
+
 /**
  * @brief implementation of symmetric matrix_expression with a value
  * of 1 for the diagonal values and 0 for all the others.
- *  
+ *
  * @tparam F The type of the stored values
- *  
+ *
  * matrix is m x n, addressing i,j is 0 <= i < m and 0 <= j < n
  * element m i,j is mapped to [i * n + j] and thus storage is row major
  */
@@ -449,11 +491,11 @@ class identity_matrix : public matrix_expression<identity_matrix<F>>
 	{
 	}
 
-	constexpr std::size_t dim_m() const { return m_n; } ///< Return dimension m
-	constexpr std::size_t dim_n() const { return m_n; } ///< Return dimension n
+	[[nodiscard]] constexpr std::size_t dim_m() const { return m_n; } ///< Return dimension m
+	[[nodiscard]] constexpr std::size_t dim_n() const { return m_n; } ///< Return dimension n
 
 	/** Return the value of element [ @a i, @a j ] */
-	constexpr value_type operator()(std::size_t i, std::size_t j) const
+	[[nodiscard]] constexpr value_type operator()(std::size_t i, std::size_t j) const
 	{
 		return static_cast<value_type>(i == j ? 1 : 0);
 	}
@@ -467,7 +509,7 @@ class identity_matrix : public matrix_expression<identity_matrix<F>>
 
 /**
  * @brief Implementation of a substraction operation as a matrix expression
- * 
+ *
  * @tparam M1 Type of matrix 1
  * @tparam M2 Type of matrix 2
  */
@@ -484,11 +526,11 @@ class matrix_subtraction : public matrix_expression<matrix_subtraction<M1, M2>>
 		assert(m_m1.dim_n() == m_m2.dim_n());
 	}
 
-	constexpr std::size_t dim_m() const { return m_m1.dim_m(); } ///< Return dimension m
-	constexpr std::size_t dim_n() const { return m_m1.dim_n(); } ///< Return dimension n
+	[[nodiscard]] constexpr std::size_t dim_m() const { return m_m1.dim_m(); } ///< Return dimension m
+	[[nodiscard]] constexpr std::size_t dim_n() const { return m_m1.dim_n(); } ///< Return dimension n
 
 	/** Access to the value of element [ @a i, @a j ] */
-	constexpr auto operator()(std::size_t i, std::size_t j) const
+	[[nodiscard]] constexpr auto operator()(std::size_t i, std::size_t j) const
 	{
 		return m_m1(i, j) - m_m2(i, j);
 	}
@@ -507,7 +549,7 @@ auto operator-(const matrix_expression<M1> &m1, const matrix_expression<M2> &m2)
 
 /**
  * @brief Implementation of a multiplication operation as a matrix expression
- * 
+ *
  * @tparam M1 Type of matrix 1
  * @tparam M2 Type of matrix 2
  */
@@ -520,20 +562,20 @@ class matrix_matrix_multiplication : public matrix_expression<matrix_matrix_mult
 		: m_m1(m1)
 		, m_m2(m2)
 	{
-		assert(m1.dim_m() == m2.dim_n());
+		assert(m1.dim_n() == m2.dim_m());
 	}
 
-	constexpr std::size_t dim_m() const { return m_m1.dim_m(); } ///< Return dimension m
-	constexpr std::size_t dim_n() const { return m_m1.dim_n(); } ///< Return dimension n
+	[[nodiscard]] constexpr std::size_t dim_m() const { return m_m1.dim_m(); } ///< Return dimension m
+	[[nodiscard]] constexpr std::size_t dim_n() const { return m_m1.dim_n(); } ///< Return dimension n
 
 	/** Access to the value of element [ @a i, @a j ] */
-	constexpr auto operator()(std::size_t i, std::size_t j) const
+	[[nodiscard]] constexpr auto operator()(std::size_t i, std::size_t j) const
 	{
 		using value_type = decltype(m_m1(0, 0));
 
 		value_type result = {};
 
-		for (std::size_t k = 0; k < m_m1.dim_m(); ++k)
+		for (std::size_t k = 0; k < m_m1.dim_n(); ++k)
 			result += m_m1(i, k) * m_m2(k, j);
 
 		return result;
@@ -546,7 +588,7 @@ class matrix_matrix_multiplication : public matrix_expression<matrix_matrix_mult
 
 /**
  * @brief Implementation of a multiplication operation of a matrix and a scalar value as a matrix expression
- * 
+ *
  * @tparam M1 Type of matrix
  * @tparam M2 Type of scalar value
  */
@@ -564,11 +606,11 @@ class matrix_scalar_multiplication : public matrix_expression<matrix_scalar_mult
 	{
 	}
 
-	constexpr std::size_t dim_m() const { return m_m.dim_m(); } ///< Return dimension m
-	constexpr std::size_t dim_n() const { return m_m.dim_n(); } ///< Return dimension n
+	[[nodiscard]] constexpr std::size_t dim_m() const { return m_m.dim_m(); } ///< Return dimension m
+	[[nodiscard]] constexpr std::size_t dim_n() const { return m_m.dim_n(); } ///< Return dimension n
 
 	/** Access to the value of element [ @a i, @a j ] */
-	constexpr auto operator()(std::size_t i, std::size_t j) const
+	[[nodiscard]] constexpr auto operator()(std::size_t i, std::size_t j) const
 	{
 		return m_m(i, j) * m_v;
 	}
@@ -579,23 +621,56 @@ class matrix_scalar_multiplication : public matrix_expression<matrix_scalar_mult
 };
 
 /** First implementation of operator*, enabled if the second parameter is a scalar */
-template <typename M1, typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
+template <typename M1, typename T>
 auto operator*(const matrix_expression<M1> &m, T v)
+	requires(std::is_floating_point_v<T>)
 {
 	return matrix_scalar_multiplication(m, v);
 }
 
 /** First implementation of operator*, enabled if the second parameter is not a scalar and thus must be a matrix, right? */
-template <typename M1, typename M2, std::enable_if_t<not std::is_floating_point_v<M2>, int> = 0>
+template <typename M1, typename M2>
 auto operator*(const matrix_expression<M1> &m1, const matrix_expression<M2> &m2)
+	requires(not std::is_floating_point_v<M2>)
 {
 	return matrix_matrix_multiplication(m1, m2);
 }
 
 // --------------------------------------------------------------------
 
+/// A sub-view on a matrix
+template <typename M2>
+class sub_matrix : public matrix_expression<sub_matrix<M2>>
+{
+  public:
+	/// Constructor
+	sub_matrix(const M2 &m, int i, int j)
+		: m_m(m)
+		, m_i(i)
+		, m_j(j)
+	{
+	}
+
+	[[nodiscard]] constexpr std::size_t dim_m() const { return m_m.dim_m() - 1; } ///< Return dimension m
+	[[nodiscard]] constexpr std::size_t dim_n() const { return m_m.dim_n() - 1; } ///< Return dimension n
+
+	/** Access to the value of element [ @a i, @a j ] */
+	[[nodiscard]] constexpr auto operator()(std::size_t i, std::size_t j) const
+	{
+		return m_m(
+			i >= m_i ? i + 1 : i,
+			j >= m_j ? j + 1 : j);
+	}
+
+  private:
+	const M2 &m_m;
+	std::size_t m_i, m_j;
+};
+
+// --------------------------------------------------------------------
+
 /** Generic routine to calculate the determinant of a matrix
- * 
+ *
  * @note This is currently only implemented for fixed matrices of size 3x3
  */
 template <typename M>
@@ -605,13 +680,25 @@ auto determinant(const M &m);
 template <typename F = float>
 auto determinant(const matrix3x3<F> &m)
 {
-	return (m(0, 0) * (m(1, 1) * m(2, 2) - m(1, 2) * m(2, 1)) +
-			m(0, 1) * (m(1, 2) * m(2, 0) - m(1, 0) * m(2, 2)) +
-			m(0, 2) * (m(1, 0) * m(2, 1) - m(1, 1) * m(2, 0)));
+	return (m(0, 0) * ((m(1, 1) * m(2, 2) - m(1, 2) * m(2, 1))) +
+			m(0, 1) * ((m(1, 2) * m(2, 0) - m(1, 0) * m(2, 2))) +
+			m(0, 2) * ((m(1, 0) * m(2, 1) - m(1, 1) * m(2, 0))));
 }
 
+/** Implementation of the determinant function for fixed size matrices of size 4x4 */
+template <typename F = float>
+F determinant(const matrix4x4<F> &m)
+{
+	return m(0, 0) * determinant(matrix3x3<F>(sub_matrix<decltype(m)>(m, 0, 0))) -
+	       m(0, 1) * determinant(matrix3x3<F>(sub_matrix<decltype(m)>(m, 0, 1))) +
+	       m(0, 2) * determinant(matrix3x3<F>(sub_matrix<decltype(m)>(m, 0, 2))) -
+	       m(0, 3) * determinant(matrix3x3<F>(sub_matrix<decltype(m)>(m, 0, 3)));
+}
+
+// --------------------------------------------------------------------
+
 /** Generic routine to calculate the inverse of a matrix
- * 
+ *
  * @note This is currently only implemented for fixed matrices of size 3x3
  */
 template <typename M>
@@ -642,7 +729,7 @@ matrix3x3<F> inverse(const matrix3x3<F> &m)
 
 /**
  * @brief Implementation of a cofactor calculation as a matrix expression
- * 
+ *
  * @tparam M Type of matrix
  */
 template <typename M>
@@ -655,11 +742,11 @@ class matrix_cofactors : public matrix_expression<matrix_cofactors<M>>
 	{
 	}
 
-	constexpr std::size_t dim_m() const { return m_m.dim_m(); } ///< Return dimension m
-	constexpr std::size_t dim_n() const { return m_m.dim_n(); } ///< Return dimension n
+	[[nodiscard]] constexpr std::size_t dim_m() const { return m_m.dim_m(); } ///< Return dimension m
+	[[nodiscard]] constexpr std::size_t dim_n() const { return m_m.dim_n(); } ///< Return dimension n
 
 	/** Access to the value of element [ @a i, @a j ] */
-	constexpr auto operator()(std::size_t i, std::size_t j) const
+	[[nodiscard]] constexpr auto operator()(std::size_t i, std::size_t j) const
 	{
 		const std::size_t ixs[4][3] = {
 			{ 1, 2, 3 },

include/cif++/model.hpp

@@ -29,12 +29,13 @@
 #include "cif++/atom_type.hpp"
 #include "cif++/datablock.hpp"
 #include "cif++/point.hpp"
+#include "cif++/row.hpp"
 
 #include <memory>
-#include <numeric>
 
 #if __cpp_lib_format
 # include <format>
+# include <utility>
 #endif
 
 /** @file model.hpp
@@ -55,6 +56,11 @@
  *
  */
 
+namespace cif
+{
+class file;
+}
+
 namespace cif::mm
 {
 
@@ -86,14 +92,14 @@ class atom
 	/** @cond */
 	struct atom_impl : public std::enable_shared_from_this<atom_impl>
 	{
-		atom_impl(const datablock &db, std::string_view id)
+		atom_impl(datablock &db, std::string_view id)
 			: m_db(db)
 			, m_cat(db["atom_site"])
 			, m_id(id)
 		{
 			auto r = row();
 			if (r)
-				tie(m_location.m_x, m_location.m_y, m_location.m_z) = r.get("Cartn_x", "Cartn_y", "Cartn_z");
+				std::tie(m_location.m_x, m_location.m_y, m_location.m_z) = r.get<float, float, float>("Cartn_x", "Cartn_y", "Cartn_z");
 		}
 
 		// constructor for a symmetry copy of an atom
@@ -106,46 +112,49 @@ class atom
 
 		atom_impl(const atom_impl &i) = default;
 
-		int compare(const atom_impl &b) const;
+		[[nodiscard]] int compare(const atom_impl &b) const;
 
 		// bool getAnisoU(float anisou[6]) const;
 
-		int get_charge() const;
+		[[nodiscard]] int get_charge() const;
 
 		void moveTo(const point &p);
 
 		// const compound *compound() const;
 
-		std::string get_property(std::string_view name) const;
-		int get_property_int(std::string_view name) const;
-		float get_property_float(std::string_view name) const;
-
-		void set_property(const std::string_view name, const std::string &value);
+		[[nodiscard]] const item_value &get_property(std::string_view name) const;
+		void set_property(const std::string_view name, item_value value);
 
 		row_handle row()
 		{
-			return m_cat[{ { "id", m_id } }];
+			return m_cat[{ { .name = "id", .value = m_id } }];
 		}
 
-		const row_handle row() const
+		[[nodiscard]] const_row_handle row() const
 		{
-			return m_cat[{ { "id", m_id } }];
+			return m_cat[{ { .name = "id", .value = m_id } }];
 		}
 
 		row_handle row_aniso()
 		{
+			row_handle result{};
 			auto cat = m_db.get("atom_site_anisotrop");
-			return cat ? cat->operator[]({ { "id", m_id } }) : row_handle{};
+			if (cat)
+				result = cat->operator[]({ { .name = "id", .value = m_id } });
+			return result;
 		}
 
-		const row_handle row_aniso() const
+		[[nodiscard]] const_row_handle row_aniso() const
 		{
+			row_handle result{};
 			auto cat = m_db.get("atom_site_anisotrop");
-			return cat ? cat->operator[]({ { "id", m_id } }) : row_handle{};
+			if (cat)
+				result = cat->operator[]({ { .name = "id", .value = m_id } });
+			return result;
 		}
 
-		const datablock &m_db;
-		const category &m_cat;
+		datablock &m_db;
+		category &m_cat;
 		std::string m_id;
 		point m_location;
 		std::string m_symop = "1_555";
@@ -156,7 +165,7 @@ class atom
 	/**
 	 * @brief Construct a new, empty atom object
 	 */
-	atom() {}
+	atom() = default;
 
 	/**
 	 * @brief Construct a new atom object using @a impl as impl
@@ -164,26 +173,41 @@ class atom
 	 * @param impl The implementation objectt
 	 */
 	atom(std::shared_ptr<atom_impl> impl)
-		: m_impl(impl)
+		: m_impl(std::move(impl))
 	{
 	}
 
 	/**
 	 * @brief Copy construct a new atom object
 	 */
-	atom(const atom &rhs)
+	atom(const atom &rhs) // NOLINT(modernize-use-equals-default)
 		: m_impl(rhs.m_impl)
 	{
 	}
 
+	/**
+	 * @brief Move construct a new atom object
+	 */
+	atom(atom &&rhs)
+	{
+		std::swap(m_impl, rhs.m_impl);
+	}
+
+	/// \brief Copy assignement operator
+	atom &operator=(atom rhs)
+	{
+		std::swap(m_impl, rhs.m_impl);
+		return *this;
+	}
+
 	/**
 	 * @brief Construct a new atom object based on a cif::row
 	 *
 	 * @param db The datablock where the _atom_site category resides
 	 * @param row The row containing the data for this atom
 	 */
-	atom(const datablock &db, const row_handle &row)
-		: atom(std::make_shared<atom_impl>(db, row["id"].as<std::string>()))
+	atom(datablock &db, const_row_handle row)
+		: atom(std::make_shared<atom_impl>(db, row["id"].get<std::string>()))
 	{
 	}
 
@@ -200,46 +224,46 @@ class atom
 	}
 
 	/// \brief To quickly test if the atom has data
-	explicit operator bool() const { return (bool)m_impl; }
-
-	/// \brief Copy assignement operator
-	atom &operator=(const atom &rhs) = default;
+	explicit operator bool() const { return m_impl.operator bool(); }
 
 	/// \brief Return the item named @a name in the _atom_site category for this atom
-	std::string get_property(std::string_view name) const
+	[[nodiscard]] const item_value &get_property_value(std::string_view name) const
 	{
 		if (not m_impl)
 			throw std::logic_error("Error trying to fetch a property from an uninitialized atom");
 		return m_impl->get_property(name);
 	}
 
-	/// \brief Return the item named @a name in the _atom_site category for this atom cast to an int
-	int get_property_int(std::string_view name) const
+	/// \brief Return the item named @a name in the _atom_site category for this atom as string
+	[[nodiscard]] auto get_property(std::string_view name) const
 	{
-		if (not m_impl)
-			throw std::logic_error("Error trying to fetch a property from an uninitialized atom");
-		return m_impl->get_property_int(name);
+		return get_property_value(name).get<std::string>();
 	}
 
-	/// \brief Return the item named @a name in the _atom_site category for this atom cast to a float
-	float get_property_float(std::string_view name) const
+	/// \brief Return the item named @a name in the _atom_site category for this atom as float
+	[[nodiscard]] auto get_property_float(std::string_view name) const
 	{
-		if (not m_impl)
-			throw std::logic_error("Error trying to fetch a property from an uninitialized atom");
-		return m_impl->get_property_float(name);
+		return get_property_value(name).get<float>();
+	}
+
+	/// \brief Return the item named @a name in the _atom_site category for this atom as string
+	[[nodiscard]] auto get_property_int(std::string_view name) const
+	{
+		return get_property_value(name).get<int>();
 	}
 
 	/// \brief Set value for the item named @a name in the _atom_site category to @a value
-	void set_property(const std::string_view name, const std::string &value)
+	void set_property(const std::string_view name, item_value value)
 	{
 		if (not m_impl)
 			throw std::logic_error("Error trying to modify an uninitialized atom");
-		m_impl->set_property(name, value);
+		m_impl->set_property(name, std::move(value));
 	}
 
 	/// \brief Set value for the item named @a name in the _atom_site category to @a value
-	template <typename T, std::enable_if_t<std::is_arithmetic_v<T>, int> = 0>
+	template <typename T>
 	void set_property(const std::string_view name, const T &value)
+		requires(std::is_arithmetic_v<T>)
 	{
 		set_property(name, std::to_string(value));
 	}
@@ -249,13 +273,13 @@ class atom
 	 * @note Although I've never seen anything other than integers,
 	 * the standard says this should be a string and so we use that.
 	 */
-	const std::string &id() const { return impl().m_id; }
+	[[nodiscard]] const std::string &id() const { return impl().m_id; }
 
 	/// \brief Return the type of the atom
-	cif::atom_type get_type() const { return atom_type_traits(get_property("type_symbol")).type(); }
+	[[nodiscard]] cif::atom_type get_type() const { return atom_type_traits(get_property("type_symbol")).type(); }
 
 	/// \brief Return the cached location of this atom
-	point get_location() const { return impl().m_location; }
+	[[nodiscard]] point get_location() const { return impl().m_location; }
 
 	/// \brief Set the location of this atom, will set both the cached data as well as the data in the underlying _atom_site category
 	void set_location(point p)
@@ -307,56 +331,56 @@ class atom
 	}
 
 	/// for direct access to underlying data, be careful!
-	const row_handle get_row() const { return impl().row(); }
+	[[nodiscard]] const_row_handle get_row() const { return impl().row(); }
 
 	/// for direct access to underlying data, be careful!
-	const row_handle get_row_aniso() const { return impl().row_aniso(); }
+	[[nodiscard]] const_row_handle get_row_aniso() const { return impl().row_aniso(); }
 
 	/// Return if the atom is actually a symmetry copy or the original one
-	bool is_symmetry_copy() const { return impl().m_symop != "1_555"; }
+	[[nodiscard]] bool is_symmetry_copy() const { return impl().m_symop != "1_555"; }
 
 	/// Return the symmetry operator used
-	std::string symmetry() const { return impl().m_symop; }
+	[[nodiscard]] std::string symmetry() const { return impl().m_symop; }
 
 	/// Return true if this atom is part of a water molecule
-	bool is_water() const
+	[[nodiscard]] bool is_water() const
 	{
 		auto comp_id = get_label_comp_id();
 		return comp_id == "HOH" or comp_id == "H2O" or comp_id == "WAT";
 	}
 
 	/// Return the charge
-	int get_charge() const { return impl().get_charge(); }
+	[[nodiscard]] int get_charge() const { return impl().get_charge(); }
 
 	/// Return the occupancy
-	float get_occupancy() const { return get_property_float("occupancy"); }
+	[[nodiscard]] float get_occupancy() const { return get_property_float("occupancy"); }
 
 	// specifications
 
-	std::string get_label_asym_id() const { return get_property("label_asym_id"); }     ///< Return the label_asym_id property
-	int get_label_seq_id() const { return get_property_int("label_seq_id"); }           ///< Return the label_seq_id property
-	std::string get_label_atom_id() const { return get_property("label_atom_id"); }     ///< Return the label_atom_id property
-	std::string get_label_alt_id() const { return get_property("label_alt_id"); }       ///< Return the label_alt_id property
-	std::string get_label_comp_id() const { return get_property("label_comp_id"); }     ///< Return the label_comp_id property
-	std::string get_label_entity_id() const { return get_property("label_entity_id"); } ///< Return the label_entity_id property
+	[[nodiscard]] std::string get_label_asym_id() const { return get_property("label_asym_id"); }     ///< Return the label_asym_id property
+	[[nodiscard]] int get_label_seq_id() const { return get_property_int("label_seq_id"); }           ///< Return the label_seq_id property
+	[[nodiscard]] std::string get_label_atom_id() const { return get_property("label_atom_id"); }     ///< Return the label_atom_id property
+	[[nodiscard]] std::string get_label_alt_id() const { return get_property("label_alt_id"); }       ///< Return the label_alt_id property
+	[[nodiscard]] std::string get_label_comp_id() const { return get_property("label_comp_id"); }     ///< Return the label_comp_id property
+	[[nodiscard]] std::string get_label_entity_id() const { return get_property("label_entity_id"); } ///< Return the label_entity_id property
 
-	std::string get_auth_asym_id() const { return get_property("auth_asym_id"); }      ///< Return the auth_asym_id property
-	std::string get_auth_seq_id() const { return get_property("auth_seq_id"); }        ///< Return the auth_seq_id property
-	std::string get_auth_atom_id() const { return get_property("auth_atom_id"); }      ///< Return the auth_atom_id property
-	std::string get_auth_alt_id() const { return get_property("pdbx_auth_alt_id"); }   ///< Return the auth_alt_id property
-	std::string get_auth_comp_id() const { return get_property("auth_comp_id"); }      ///< Return the auth_comp_id property
-	std::string get_pdb_ins_code() const { return get_property("pdbx_PDB_ins_code"); } ///< Return the pdb_ins_code property
+	[[nodiscard]] std::string get_auth_asym_id() const { return get_property("auth_asym_id"); }      ///< Return the auth_asym_id property
+	[[nodiscard]] std::string get_auth_seq_id() const { return get_property("auth_seq_id"); }        ///< Return the auth_seq_id property
+	[[nodiscard]] std::string get_auth_atom_id() const { return get_property("auth_atom_id"); }      ///< Return the auth_atom_id property
+	[[nodiscard]] std::string get_auth_alt_id() const { return get_property("pdbx_auth_alt_id"); }   ///< Return the auth_alt_id property
+	[[nodiscard]] std::string get_auth_comp_id() const { return get_property("auth_comp_id"); }      ///< Return the auth_comp_id property
+	[[nodiscard]] std::string get_pdb_ins_code() const { return get_property("pdbx_PDB_ins_code"); } ///< Return the pdb_ins_code property
 
 	/// Return true if this atom is an alternate
-	bool is_alternate() const
+	[[nodiscard]] bool is_alternate() const
 	{
-		if (auto alt_id = get_label_alt_id(); alt_id.empty() or alt_id == ".")
+		if (auto alt_id = get_property_value("label_alt_id"); alt_id.empty())
 			return false;
 		return true;
 	}
 
 	/// Convenience method to return a string that might be ID in PDB space
-	std::string pdb_id() const
+	[[nodiscard]] std::string pdb_id() const
 	{
 		return get_label_comp_id() + '_' + get_auth_asym_id() + '_' + get_auth_seq_id() + get_pdb_ins_code();
 	}
@@ -380,7 +404,7 @@ class atom
 	}
 
 	/// Is this atom a backbone atom
-	bool is_back_bone() const
+	[[nodiscard]] bool is_back_bone() const
 	{
 		auto atomID = get_label_atom_id();
 		return atomID == "N" or atomID == "O" or atomID == "C" or atomID == "CA";
@@ -393,7 +417,7 @@ class atom
 	}
 
 	/// Compare this atom with @a b
-	int compare(const atom &b) const { return impl().compare(*b.m_impl); }
+	[[nodiscard]] int compare(const atom &b) const { return impl().compare(*b.m_impl); }
 
 	/// Should this atom sort before @a rhs
 	bool operator<(const atom &rhs) const
@@ -407,7 +431,7 @@ class atom
   private:
 	friend class structure;
 
-	const atom_impl &impl() const
+	[[nodiscard]] const atom_impl &impl() const
 	{
 		if (not m_impl)
 			throw std::runtime_error("Uninitialized atom, not found?");
@@ -471,17 +495,15 @@ class residue
 	/**
 	 * @brief Construct a new residue object based on key items
 	 */
-	residue(structure &structure, const std::string &compoundID,
-		const std::string &asymID, int seqID,
-		const std::string &authAsymID, const std::string &authSeqID,
-		const std::string &pdbInsCode)
+	residue(structure &structure, std::string compoundID, std::string asymID, int seqID,
+		std::string authAsymID, std::string authSeqID, std::string pdbInsCode)
 		: m_structure(&structure)
-		, m_compound_id(compoundID)
-		, m_asym_id(asymID)
+		, m_compound_id(std::move(compoundID))
+		, m_asym_id(std::move(asymID))
 		, m_seq_id(seqID)
-		, m_pdb_strand_id(authAsymID)
-		, m_pdb_seq_num(authSeqID)
-		, m_pdb_ins_code(pdbInsCode)
+		, m_pdb_strand_id(std::move(authAsymID))
+		, m_pdb_seq_num(std::move(authSeqID))
+		, m_pdb_ins_code(std::move(pdbInsCode))
 	{
 	}
 
@@ -489,33 +511,51 @@ class residue
 	residue(structure &structure, const std::vector<atom> &atoms);
 
 	/** @cond */
-	residue(const residue &rhs) = delete;
-	residue &operator=(const residue &rhs) = delete;
+	residue(const residue &rhs) = default;
+	residue(residue &&rhs)
+	{
+		swap(*this, rhs);
+	}
 
-	residue(residue &&rhs) = default;
-	residue &operator=(residue &&rhs) = default;
+	residue &operator=(residue rhs)
+	{
+		swap(*this, rhs);
+		return *this;
+	}
+
+	friend void swap(residue &a, residue &b) noexcept
+	{
+		if (&a != &b)
+		{
+			std::swap(a.m_structure, b.m_structure);
+			std::swap(a.m_asym_id, b.m_asym_id);
+			std::swap(a.m_seq_id, b.m_seq_id);
+			std::swap(a.m_pdb_ins_code, b.m_pdb_ins_code);
+			std::swap(a.m_atoms, b.m_atoms);
+		}
+	}
 
 	virtual ~residue() = default;
 	/** @endcond */
 
 	/** Return the entity_id of this residue */
-	std::string get_entity_id() const;
+	[[nodiscard]] std::string get_entity_id() const;
 
 	/** Return the entity type of this residue */
-	EntityType entity_type() const;
+	[[nodiscard]] EntityType entity_type() const;
 
-	const std::string &get_asym_id() const { return m_asym_id; } ///< Return the asym_id
-	int get_seq_id() const { return m_seq_id; }                  ///< Return the seq_id
+	[[nodiscard]] const std::string &get_asym_id() const { return m_asym_id; } ///< Return the asym_id
+	[[nodiscard]] int get_seq_id() const { return m_seq_id; }                  ///< Return the seq_id
 
-	const std::string get_pdb_strand_id() const { return m_pdb_strand_id; } ///< Return the pdb_strand_id
-	const std::string get_pdb_seq_num() const { return m_pdb_seq_num; }     ///< Return the pdb_seq_num
-	std::string get_pdb_ins_code() const { return m_pdb_ins_code; }         ///< Return the pdb_ins_code
+	[[nodiscard]] const std::string get_pdb_strand_id() const { return m_pdb_strand_id; } ///< Return the pdb_strand_id
+	[[nodiscard]] const std::string get_pdb_seq_num() const { return m_pdb_seq_num; }     ///< Return the pdb_seq_num
+	[[nodiscard]] std::string get_pdb_ins_code() const { return m_pdb_ins_code; }         ///< Return the pdb_ins_code
 
-	const std::string &get_compound_id() const { return m_compound_id; } ///< Return the compound_id
-	void set_compound_id(const std::string &id) { m_compound_id = id; }  ///< Set the compound_id to @a id
+	[[nodiscard]] const std::string &get_compound_id() const { return m_compound_id; } ///< Return the compound_id
+	void set_compound_id(const std::string &id) { m_compound_id = id; }                ///< Set the compound_id to @a id
 
 	/** Return the structure this residue belongs to */
-	structure *get_structure() const { return m_structure; }
+	[[nodiscard]] structure *get_structure() const { return m_structure; }
 
 	/** Return a list of the atoms for this residue */
 	std::vector<atom> &atoms()
@@ -524,7 +564,7 @@ class residue
 	}
 
 	/** Return a const list of the atoms for this residue */
-	const std::vector<atom> &atoms() const
+	[[nodiscard]] const std::vector<atom> &atoms() const
 	{
 		return m_atoms;
 	}
@@ -533,40 +573,40 @@ class residue
 	void add_atom(atom &atom);
 
 	/// \brief Unique atoms returns only the atoms without alternates and the first of each alternate atom id.
-	std::vector<atom> unique_atoms() const;
+	[[nodiscard]] std::vector<atom> unique_atoms() const;
 
 	/// \brief Return the atom with atom_id @a atomID
-	atom get_atom_by_atom_id(const std::string &atomID) const;
+	[[nodiscard]] atom get_atom_by_atom_id(const std::string &atomID) const;
 
 	/// \brief Return the atom with atom_id @a atomID and alternate_id @a altID
-	atom get_atom_by_atom_id(const std::string &atomID, const std::string &altID) const;
+	[[nodiscard]] atom get_atom_by_atom_id(const std::string &atomID, const std::string &altID) const;
 
 	/// \brief Return the list of atoms having ID \a atomID
 	///
 	/// This includes all alternate atoms with this ID
 	/// whereas get_atom_by_atom_id only returns the first unique atom
-	std::vector<atom> get_atoms_by_id(const std::string &atomID) const;
+	[[nodiscard]] std::vector<atom> get_atoms_by_id(const std::string &atomID) const;
 
 	/// \brief Is this residue a single entity?
-	bool is_entity() const;
+	[[nodiscard]] bool is_entity() const;
 
 	/// \brief Is this residue a water molecule?
-	bool is_water() const { return m_compound_id == "HOH"; }
+	[[nodiscard]] bool is_water() const { return m_compound_id == "HOH"; }
 
 	/// \brief Return true if this residue has alternate atoms
-	bool has_alternate_atoms() const;
+	[[nodiscard]] bool has_alternate_atoms() const;
 
 	/// \brief Return true if this residue has alternate atoms for the atom \a atomID
-	bool has_alternate_atoms_for(const std::string &atomID) const;
+	[[nodiscard]] bool has_alternate_atoms_for(const std::string &atomID) const;
 
 	/// \brief Return the list of unique alt ID's present in this residue
-	std::set<std::string> get_alternate_ids() const;
+	[[nodiscard]] std::set<std::string> get_alternate_ids() const;
 
 	/// \brief Return the list of unique atom ID's
-	std::set<std::string> get_atom_ids() const;
+	[[nodiscard]] std::set<std::string> get_atom_ids() const;
 
 	/// \brief Return a tuple containing the center location and the radius for the atoms of this residue
-	std::tuple<point, float> center_and_radius() const;
+	[[nodiscard]] std::tuple<point, float> center_and_radius() const;
 
 	/// \brief Write the residue @a res to the std::ostream @a os
 	friend std::ostream &operator<<(std::ostream &os, const residue &res);
@@ -587,7 +627,7 @@ class residue
 
   protected:
 	/** @cond */
-	residue() {}
+	residue() = default;
 
 	structure *m_structure = nullptr;
 	std::string m_compound_id, m_asym_id;
@@ -607,58 +647,73 @@ class residue
 class monomer : public residue
 {
   public:
-	monomer(const monomer &rhs) = delete;
-	monomer &operator=(const monomer &rhs) = delete;
-
-	/// \brief Move constructor
-	monomer(monomer &&rhs);
-
-	/// \brief Move assignment operator
-	monomer &operator=(monomer &&rhs);
-
 	/// \brief constructor with actual values
 	monomer(const polymer &polymer, std::size_t index, int seqID, const std::string &authSeqID,
 		const std::string &pdbInsCode, const std::string &compoundID);
 
-	bool is_first_in_chain() const; ///< Return if this residue is the first residue in the chain
-	bool is_last_in_chain() const;  ///< Return if this residue is the last residue in the chain
+	/// \brief Copy constructor
+	monomer(const monomer &rhs) = default;
 
-	const monomer &prev() const; // Return previous monomer in polymer
-	const monomer &next() const; // Return next monomer in polymer
+	/// \brief Move constructor
+	monomer(monomer &&rhs)
+	{
+		swap(*this, rhs);
+	}
+
+	/// Assignment for both move and copy (modern move semantics)
+	monomer &operator=(monomer rhs)
+	{
+		swap(*this, rhs);
+		return *this;
+	}
+
+	/// swap two monomers
+	friend void swap(monomer &a, monomer &b) noexcept
+	{
+		assert(a.m_polymer == b.m_polymer);
+		std::swap(a.m_index, b.m_index);
+		swap(static_cast<residue &>(a), static_cast<residue &>(b));
+	}
+
+	[[nodiscard]] bool is_first_in_chain() const; ///< Return if this residue is the first residue in the chain
+	[[nodiscard]] bool is_last_in_chain() const;  ///< Return if this residue is the last residue in the chain
+
+	[[nodiscard]] const monomer &prev() const; ///< Return previous monomer in polymer
+	[[nodiscard]] const monomer &next() const; ///< Return next monomer in polymer
 
 	// convenience
-	bool has_alpha() const; ///< Return if a alpha value can be calculated (depends on location in chain)
-	bool has_kappa() const; ///< Return if a kappa value can be calculated (depends on location in chain)
+	[[nodiscard]] bool has_alpha() const; ///< Return if a alpha value can be calculated (depends on location in chain)
+	[[nodiscard]] bool has_kappa() const; ///< Return if a kappa value can be calculated (depends on location in chain)
 
 	// Assuming this is really an amino acid...
 
-	float phi() const;   ///< Return the phi value for this residue
-	float psi() const;   ///< Return the psi value for this residue
-	float alpha() const; ///< Return the alpha value for this residue
-	float kappa() const; ///< Return the kappa value for this residue
-	float tco() const;   ///< Return the tco value for this residue
-	float omega() const; ///< Return the omega value for this residue
+	[[nodiscard]] float phi() const;   ///< Return the phi value for this residue
+	[[nodiscard]] float psi() const;   ///< Return the psi value for this residue
+	[[nodiscard]] float alpha() const; ///< Return the alpha value for this residue
+	[[nodiscard]] float kappa() const; ///< Return the kappa value for this residue
+	[[nodiscard]] float tco() const;   ///< Return the tco value for this residue
+	[[nodiscard]] float omega() const; ///< Return the omega value for this residue
 
 	// torsion angles
-	std::size_t nr_of_chis() const; ///< Return how many torsion angles can be calculated
-	float chi(std::size_t i) const; ///< Return torsion angle @a i
+	[[nodiscard]] std::size_t nr_of_chis() const; ///< Return how many torsion angles can be calculated
+	[[nodiscard]] float chi(std::size_t i) const; ///< Return torsion angle @a i
 
-	bool is_cis() const; ///< Return true if this residue is in a cis conformation
+	[[nodiscard]] bool is_cis() const; ///< Return true if this residue is in a cis conformation
 
 	/// \brief Returns true if the four atoms C, CA, N and O are present
-	bool is_complete() const;
+	[[nodiscard]] bool is_complete() const;
 
 	/// \brief Returns true if any of the backbone atoms has an alternate
-	bool has_alternate_backbone_atoms() const;
+	[[nodiscard]] bool has_alternate_backbone_atoms() const;
 
-	atom CAlpha() const { return get_atom_by_atom_id("CA"); } ///< Return the CAlpha atom
-	atom C() const { return get_atom_by_atom_id("C"); }       ///< Return the C atom
-	atom N() const { return get_atom_by_atom_id("N"); }       ///< Return the N atom
-	atom O() const { return get_atom_by_atom_id("O"); }       ///< Return the O atom
-	atom H() const { return get_atom_by_atom_id("H"); }       ///< Return the H atom
+	[[nodiscard]] atom CAlpha() const { return get_atom_by_atom_id("CA"); } ///< Return the CAlpha atom
+	[[nodiscard]] atom C() const { return get_atom_by_atom_id("C"); }       ///< Return the C atom
+	[[nodiscard]] atom N() const { return get_atom_by_atom_id("N"); }       ///< Return the N atom
+	[[nodiscard]] atom O() const { return get_atom_by_atom_id("O"); }       ///< Return the O atom
+	[[nodiscard]] atom H() const { return get_atom_by_atom_id("H"); }       ///< Return the H atom
 
 	/// \brief Return true if this monomer is bonded to monomer @a rhs
-	bool is_bonded_to(const monomer &rhs) const
+	[[nodiscard]] bool is_bonded_to(const monomer &rhs) const
 	{
 		return this != &rhs and are_bonded(*this, rhs);
 	}
@@ -680,7 +735,7 @@ class monomer : public residue
 	static float omega(const monomer &a, const monomer &b);
 
 	/// \brief Return the chiral volume, only for LEU and VAL
-	float chiral_volume() const;
+	[[nodiscard]] float chiral_volume() const;
 
 	/// \brief Compare this monomer with \a rhs
 	bool operator==(const monomer &rhs) const
@@ -692,7 +747,7 @@ class monomer : public residue
 
   private:
 	const polymer *m_polymer;
-	std::size_t m_index;
+	std::size_t m_index{};
 };
 
 // --------------------------------------------------------------------
@@ -705,16 +760,16 @@ class polymer : public std::vector<monomer>
 {
   public:
 	/// \brief Constructor
-	polymer(structure &s, const std::string &entityID, const std::string &asymID, const std::string &auth_asym_id);
+	polymer(structure &s, std::string entityID, std::string asymID, std::string auth_asym_id);
 
 	polymer(const polymer &) = delete;
 	polymer &operator=(const polymer &) = delete;
 
-	structure *get_structure() const { return m_structure; } ///< Return the structure
+	[[nodiscard]] structure *get_structure() const { return m_structure; } ///< Return the structure
 
-	std::string get_asym_id() const { return m_asym_id; }             ///< Return the asym_id
-	std::string get_pdb_strand_id() const { return m_pdb_strand_id; } ///< Return the PDB chain ID, actually
-	std::string get_entity_id() const { return m_entity_id; }         ///< Return the entity_id
+	[[nodiscard]] std::string get_asym_id() const { return m_asym_id; }             ///< Return the asym_id
+	[[nodiscard]] std::string get_pdb_strand_id() const { return m_pdb_strand_id; } ///< Return the PDB chain ID, actually
+	[[nodiscard]] std::string get_entity_id() const { return m_entity_id; }         ///< Return the entity_id
 
   private:
 	structure *m_structure;
@@ -741,8 +796,26 @@ class sugar : public residue
 		const std::string &asymID, int authSeqID);
 
 	/** @cond */
-	sugar(sugar &&rhs);
-	sugar &operator=(sugar &&rhs);
+	sugar(const sugar &rhs) = default;
+
+	sugar(sugar &&rhs)
+	{
+		swap(*this, rhs);
+	}
+
+	sugar &operator=(sugar rhs)
+	{
+		swap(*this, rhs);
+		return *this;
+	}
+
+	friend void swap(sugar &a, sugar &b) noexcept
+	{
+		assert(a.m_branch == b.m_branch);
+		std::swap(a.m_link, b.m_link);
+		swap(static_cast<residue &>(a), static_cast<residue &>(b));
+	}
+
 	/** @endcond */
 
 	/**
@@ -755,26 +828,26 @@ class sugar : public residue
 	 *
 	 * @return The sugar number
 	 */
-	int num() const
+	[[nodiscard]] int num() const
 	{
 		int result;
 		auto r = std::from_chars(m_pdb_seq_num.data(), m_pdb_seq_num.data() + m_pdb_seq_num.length(), result);
-		if ((bool)r.ec)
+		if (r.ec != std::errc{})
 			throw std::runtime_error("The auth_seq_id should be a number for a sugar");
 		return result;
 	}
 
 	/// \brief Return the name of this sugar
-	std::string name() const;
+	[[nodiscard]] std::string name() const;
 
 	/// \brief Return the atom the C1 is linked to
-	atom get_link() const { return m_link; }
+	[[nodiscard]] atom get_link() const { return m_link; }
 
 	/// \brief Set the link atom C1 is linked to to @a link
 	void set_link(atom link) { m_link = link; }
 
 	/// \brief Return the sugar number of the sugar linked to C1
-	std::size_t get_link_nr() const
+	[[nodiscard]] std::size_t get_link_nr() const
 	{
 		std::size_t result = 0;
 		if (m_link)
@@ -802,7 +875,7 @@ class branch : public std::vector<sugar>
 {
   public:
 	/// \brief constructor
-	branch(structure &structure, const std::string &asym_id, const std::string &entity_id);
+	branch(structure &structure, std::string asym_id, std::string entity_id);
 
 	branch(const branch &) = delete;
 	branch &operator=(const branch &) = delete;
@@ -816,22 +889,22 @@ class branch : public std::vector<sugar>
 	void link_atoms();
 
 	/// \brief Return the name of the branch
-	std::string name() const;
+	[[nodiscard]] std::string name() const;
 
 	/// \brief Return the weight of the branch based on the formulae of the sugars
-	float weight() const;
+	[[nodiscard]] float weight() const;
 
-	std::string get_asym_id() const { return m_asym_id; }     ///< Return the asym_id
-	std::string get_entity_id() const { return m_entity_id; } ///< Return the entity_id
+	[[nodiscard]] std::string get_asym_id() const { return m_asym_id; }     ///< Return the asym_id
+	[[nodiscard]] std::string get_entity_id() const { return m_entity_id; } ///< Return the entity_id
 
-	structure &get_structure() { return *m_structure; }       ///< Return the structure
-	structure &get_structure() const { return *m_structure; } ///< Return the structure
+	[[nodiscard]] structure &get_structure() { return *m_structure; }       ///< Return the structure
+	[[nodiscard]] structure &get_structure() const { return *m_structure; } ///< Return the structure
 
 	/// \brief Return a reference to the sugar with number @a num
-	sugar &get_sugar_by_num(int nr);
+	[[nodiscard]] sugar &get_sugar_by_num(int nr);
 
 	/// \brief Return a const reference to the sugar with number @a num
-	const sugar &get_sugar_by_num(int nr) const
+	[[nodiscard]] const sugar &get_sugar_by_num(int nr) const
 	{
 		return const_cast<branch *>(this)->get_sugar_by_num(nr);
 	}
@@ -851,7 +924,7 @@ class branch : public std::vector<sugar>
   private:
 	friend sugar;
 
-	std::string name(const sugar &s) const;
+	[[nodiscard]] std::string name(const sugar &s) const;
 
 	structure *m_structure;
 	std::string m_asym_id, m_entity_id;
@@ -879,6 +952,7 @@ enum class occupancy_policy
 	UNOCCUPIED = 3
 };
 
+/// When creating a structure, you can specify what to include using this options class.
 struct structure_open_options
 {
 	bool skip_hydrogen = false;                              ///< Do not include hydrogen atoms in the structure object
@@ -918,85 +992,85 @@ class structure
 	~structure() = default;
 
 	/// \brief Return the model number
-	std::size_t get_model_nr() const { return m_model_nr; }
+	[[nodiscard]] std::size_t get_model_nr() const { return m_model_nr; }
 
 	/// \brief Return a list of all the atoms in this structure
-	const std::vector<atom> &atoms() const { return m_atoms; }
+	[[nodiscard]] const std::vector<atom> &atoms() const { return m_atoms; }
 
-	EntityType get_entity_type_for_entity_id(const std::string entityID) const; ///< Return the entity type for the entity with id @a entity_id
-	EntityType get_entity_type_for_asym_id(const std::string asymID) const;     ///< Return the entity type for the asym with id @a asym_id
+	[[nodiscard]] EntityType get_entity_type_for_entity_id(const std::string entityID) const; ///< Return the entity type for the entity with id @a entity_id
+	[[nodiscard]] EntityType get_entity_type_for_asym_id(const std::string asymID) const;     ///< Return the entity type for the asym with id @a asym_id
 
-	const std::list<polymer> &polymers() const { return m_polymers; } ///< Return the list of polymers
-	std::list<polymer> &polymers() { return m_polymers; }             ///< Return the list of polymers
+	[[nodiscard]] const std::list<polymer> &polymers() const { return m_polymers; } ///< Return the list of polymers
+	[[nodiscard]] std::list<polymer> &polymers() { return m_polymers; }             ///< Return the list of polymers
 
-	polymer &get_polymer_by_asym_id(const std::string &asymID);            ///< Return the polymer having asym ID @a asymID
-	const polymer &get_polymer_by_asym_id(const std::string &asymID) const ///< Return the polymer having asym ID @a asymID
+	[[nodiscard]] polymer &get_polymer_by_asym_id(const std::string &asymID);            ///< Return the polymer having asym ID @a asymID
+	[[nodiscard]] const polymer &get_polymer_by_asym_id(const std::string &asymID) const ///< Return the polymer having asym ID @a asymID
 	{
 		return const_cast<structure *>(this)->get_polymer_by_asym_id(asymID);
 	}
 
-	const std::list<branch> &branches() const { return m_branches; } ///< Return the list of all branches
-	std::list<branch> &branches() { return m_branches; }             ///< Return the list of all branches
+	[[nodiscard]] const std::list<branch> &branches() const { return m_branches; } ///< Return the list of all branches
+	[[nodiscard]] std::list<branch> &branches() { return m_branches; }             ///< Return the list of all branches
 
-	branch &get_branch_by_asym_id(const std::string &asymID);             ///< Return the branch having asym ID @a asymID
-	const branch &get_branch_by_asym_id(const std::string &asymID) const; ///< Return the branch having asym ID @a asymID
+	[[nodiscard]] branch &get_branch_by_asym_id(const std::string &asymID);             ///< Return the branch having asym ID @a asymID
+	[[nodiscard]] const branch &get_branch_by_asym_id(const std::string &asymID) const; ///< Return the branch having asym ID @a asymID
 
-	const std::vector<residue> &non_polymers() const { return m_non_polymers; } ///< Return the list of non-polymers, actually the list of ligands
+	[[nodiscard]] const std::vector<residue> &non_polymers() const { return m_non_polymers; } ///< Return the list of non-polymers, actually the list of ligands
 
-	bool has_atom_id(const std::string &id) const;    ///< Return true if an atom with ID @a id exists in this structure
-	atom get_atom_by_id(const std::string &id) const; ///< Return the atom with ID @a id
+	[[nodiscard]] bool has_atom_id(const std::string &id) const;    ///< Return true if an atom with ID @a id exists in this structure
+	[[nodiscard]] atom get_atom_by_id(const std::string &id) const; ///< Return the atom with ID @a id
 
 	/// \brief Return the atom identified by the label_ values specified
-	atom get_atom_by_label(const std::string &atomID, const std::string &asymID,
+	[[nodiscard]] atom get_atom_by_label(const std::string &atomID, const std::string &asymID,
 		const std::string &compID, int seqID, const std::string &altID = "");
 
 	/// \brief Return the atom closest to point \a p
-	atom get_atom_by_position(point p) const;
+	[[nodiscard]] atom get_atom_by_position(point p) const;
 
 	/// \brief Return the atom closest to point \a p with atom type \a type in a residue of type \a res_type
-	atom get_atom_by_position_and_type(point p, std::string_view type, std::string_view res_type) const;
+	[[nodiscard]] atom get_atom_by_position_and_type(point p, std::string_view type, std::string_view res_type) const;
 
 	/// \brief Create a non-poly residue based on atoms already present in this structure.
 	residue &create_residue(const std::vector<atom> &atoms);
 
 	/// \brief Get a non-poly residue for an asym with id \a asymID
-	residue &get_residue(const std::string &asymID)
+	[[nodiscard]] residue &get_residue(const std::string &asymID)
 	{
 		return get_residue(asymID, 0, "");
 	}
 
 	/// \brief Get a non-poly residue for an asym with id \a asymID
-	const residue &get_residue(const std::string &asymID) const
+	[[nodiscard]] const residue &get_residue(const std::string &asymID) const
 	{
 		return get_residue(asymID, 0, "");
 	}
 
 	/// \brief Get a residue for an asym with id \a asymID seq id \a seqID and authSeqID \a authSeqID
-	residue &get_residue(const std::string &asymID, int seqID, const std::string &authSeqID);
+	[[nodiscard]] residue &get_residue(const std::string &asymID, int seqID, const std::string &authSeqID);
 
 	/// \brief Get a the single residue for an asym with id \a asymID seq id \a seqID and authSeqID \a authSeqID
-	const residue &get_residue(const std::string &asymID, int seqID, const std::string &authSeqID) const
+	[[nodiscard]] const residue &get_residue(const std::string &asymID, int seqID, const std::string &authSeqID) const
 	{
 		return const_cast<structure *>(this)->get_residue(asymID, seqID, authSeqID);
 	}
 
 	/// \brief Get a residue for an asym with id \a asymID, compound id \a compID, seq id \a seqID and authSeqID \a authSeqID
-	residue &get_residue(const std::string &asymID, const std::string &compID, int seqID, const std::string &authSeqID);
+	[[nodiscard]] residue &get_residue(const std::string &asymID, const std::string &compID, int seqID, const std::string &authSeqID);
 
 	/// \brief Get a residue for an asym with id \a asymID, compound id \a compID, seq id \a seqID and authSeqID \a authSeqID
-	const residue &get_residue(const std::string &asymID, const std::string &compID, int seqID, const std::string &authSeqID) const
+	[[nodiscard]] const residue &get_residue(const std::string &asymID, const std::string &compID, int seqID, const std::string &authSeqID) const
 	{
 		return const_cast<structure *>(this)->get_residue(asymID, compID, seqID, authSeqID);
 	}
 
 	/// \brief Get a the residue for atom \a atom
-	residue &get_residue(const atom &atom)
+	[[nodiscard]] residue &get_residue(const atom &atom)
 	{
 		return get_residue(atom.get_label_asym_id(), atom.get_label_comp_id(), atom.get_label_seq_id(), atom.get_auth_seq_id());
 	}
 
 	/// \brief Get a the residue for atom \a atom
-	const residue &get_residue(const atom &atom) const
+	[[nodiscard]] const residue &get_residue(const atom &atom) const
 	{
 		return get_residue(atom.get_label_asym_id(), atom.get_label_comp_id(), atom.get_label_seq_id(), atom.get_auth_seq_id());
 	}
@@ -1059,12 +1133,30 @@ class structure
 	/// \return				The newly create asym ID
 	std::string create_non_poly(const std::string &entity_id, std::vector<row_initializer> atoms);
 
+	/// \brief Create a new NonPolymer struct_asym for a compound of type \a compound_id, returns asym_id.
+	/// This method creates new atom records filled with info from the CCD compound info.
+	///
+	/// \param compound_id	 The compound ID of the new nonpoly
+	/// \param skip_hydrogen Do not create hydrogen atoms when true
+	/// \return				 The newly create asym ID
+	std::string create_non_poly(const std::string &compound_id, bool skip_hydrogen);
+
 	/// \brief Create a new water with atom constructed from info in \a atom_info
 	/// This method creates a new atom record filled with info from the info.
 	///
 	/// \param atom			The set of item data containing the data for the atoms.
 	void create_water(row_initializer atom);
 
+	/// \brief Create a link, a struct_conn record for two atoms.
+	///
+	/// \param a1			Atom 1
+	/// \param a2			Atom 2
+	/// \param link_type	The struct_conn_type ID for the link
+	/// \param role			The pdbx_role field value
+	/// \return 			The ID of the struct_conn record created
+
+	std::string create_link(atom a1, atom a2, const std::string &link_type, const std::string &role);
+
 	/// \brief Create a new and empty (sugar) branch
 	branch &create_branch();
 
@@ -1104,13 +1196,13 @@ class structure
 	void cleanup_empty_categories();
 
 	/// \brief Direct access to underlying data
-	category &get_category(std::string_view name) const
+	[[nodiscard]] category &get_category(std::string_view name) const
 	{
 		return m_db[name];
 	}
 
 	/// \brief Direct access to underlying data
-	datablock &get_datablock() const
+	[[nodiscard]] datablock &get_datablock() const
 	{
 		return m_db;
 	}
@@ -1119,14 +1211,13 @@ class structure
 	void validate_atoms() const;
 
 	/// \brief emplace a newly created atom using @a args
-	template <typename... Args>
-	atom &emplace_atom(Args &...args)
+	atom &emplace_atom(datablock &db, const_row_handle rh)
 	{
-		return emplace_atom(atom{ std::forward<Args>(args)... });
+		return emplace_atom(atom{ db, rh });
 	}
 
 	/// \brief emplace the moved atom @a atom
-	atom &emplace_atom(atom &&atom);
+	atom &emplace_atom(atom atom);
 
 	/// \brief Reorder atom_site atoms based on 'natural' ordering
 	void reorder_atoms();

include/cif++/parser.hpp

@@ -26,19 +26,34 @@
 
 #pragma once
 
+#include "cif++/category.hpp"
+#include "cif++/datablock.hpp"
+#include "cif++/item.hpp"
 #include "cif++/row.hpp"
+#include "cif++/text.hpp"
+#include "cif++/utilities.hpp"
 
+#include <cstddef>
+#include <cstdint>
+#include <iostream>
 #include <map>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <vector>
 
 /**
  * @file parser.hpp
- * 
+ *
  * This file contains the declaration of an mmCIF parser
  */
 
 namespace cif
 {
 
+class category;
+class datablock;
+class file;
 class validator;
 
 // --------------------------------------------------------------------
@@ -57,14 +72,14 @@ class parse_error : public std::runtime_error
 // --------------------------------------------------------------------
 
 /**
- * @brief The sac_parser is a similar to SAX parsers (Simple API for XML, 
+ * @brief The sac_parser is a similar to SAX parsers (Simple API for XML,
  * in our case it is Simple API for CIF)
- * 
+ *
  * This is a hand crafted, optimised parser for reading cif files,
  * both cif 1.0 and cif 1.1 is supported. But version 2.0 is not.
  * That means that the content of files strictly contains only
  * ASCII characters. Anything else will generate an error.
- * 
+ *
  * This class is an abstract base class. Derived classes should
  * implement the produce_ methods.
  */
@@ -92,10 +107,10 @@ class sac_parser
 	/// create a table with character properties.
 	enum CharTraitsMask : uint8_t
 	{
-		kOrdinaryMask = 1 << 0,	///< The character is in the Ordinary class
-		kNonBlankMask = 1 << 1,	///< The character is in the NonBlank class
-		kTextLeadMask = 1 << 2,	///< The character is in the TextLead class
-		kAnyPrintMask = 1 << 3	///< The character is in the AnyPrint class
+		kOrdinaryMask = 1 << 0, ///< The character is in the Ordinary class
+		kNonBlankMask = 1 << 1, ///< The character is in the NonBlank class
+		kTextLeadMask = 1 << 2, ///< The character is in the TextLead class
+		kAnyPrintMask = 1 << 3  ///< The character is in the AnyPrint class
 	};
 
 	/// \brief Return true if the character @a ch is a *space* character
@@ -143,12 +158,102 @@ class sac_parser
 
 	static constexpr uint8_t kCharTraitsTable[128] = {
 		//	0	1	2	3	4	5	6	7	8	9	a	b	c	d	e	f
-		14, 15, 14, 14, 14, 15, 15, 14, 15, 15, 15, 15, 15, 15, 15, 15, //	2
-		15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 10, 15, 15, 15, 15, //	3
-		15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, //	4
-		15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 14, 15, 14, 15, 14, //	5
-		15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, //	6
-		15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 0,  //	7
+		14,
+		15,
+		14,
+		14,
+		14,
+		15,
+		15,
+		14,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15, //	2
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		10,
+		15,
+		15,
+		15,
+		15, //	3
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15, //	4
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		14,
+		15,
+		14,
+		15,
+		14, //	5
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15, //	6
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		15,
+		0, //	7
 	};
 
 	enum class CIFToken
@@ -164,23 +269,40 @@ class sac_parser
 		SAVE_NAME,
 		STOP,
 		ITEM_NAME,
-		VALUE
+
+		VALUE_INAPPLICABLE,
+		VALUE_UNKNOWN,
+		VALUE_NUMERIC_INTEGER,
+		VALUE_NUMERIC_FLOAT,
+		VALUE_CHARSTRING,
+		VALUE_TEXTFIELD
 	};
 
 	static constexpr const char *get_token_name(CIFToken token)
 	{
 		switch (token)
 		{
-			case CIFToken::UNKNOWN: return "Unknown";
-			case CIFToken::END_OF_FILE: return "Eof";
-			case CIFToken::DATA: return "DATA";
-			case CIFToken::LOOP: return "LOOP";
-			case CIFToken::GLOBAL: return "GLOBAL";
-			case CIFToken::SAVE_: return "SAVE";
-			case CIFToken::SAVE_NAME: return "SAVE+name";
-			case CIFToken::STOP: return "STOP";
-			case CIFToken::ITEM_NAME: return "Tag";
-			case CIFToken::VALUE: return "Value";
+			using enum CIFToken;
+
+			case UNKNOWN: return "Unknown";
+			case END_OF_FILE: return "Eof";
+			case DATA: return "DATA";
+			case LOOP: return "LOOP";
+			case GLOBAL: return "GLOBAL";
+			case SAVE_: return "SAVE";
+			case SAVE_NAME: return "SAVE+name";
+			case STOP: return "STOP";
+			case ITEM_NAME:
+				return "Tag";
+				// case VALUE: return "Value";
+
+			case VALUE_INAPPLICABLE: return "Inapplicable value";
+			case VALUE_UNKNOWN: return "'Unknown' value (=null)";
+			case VALUE_NUMERIC_INTEGER: return "Integer value";
+			case VALUE_NUMERIC_FLOAT: return "Float value";
+			case VALUE_CHARSTRING: return "Charstring value";
+			case VALUE_TEXTFIELD: return "Textfield value";
+
 			default: return "Invalid token parameter";
 		}
 	}
@@ -199,7 +321,6 @@ class sac_parser
 	/** @endcond */
 
   public:
-
 	/** \brief Parse only a single datablock in the string @a datablock
 	 * The start of the datablock is first located and then data
 	 * is parsed up until the next start of a datablock or the end of
@@ -214,10 +335,10 @@ class sac_parser
 
 	/**
 	 * @brief Parse the datablock named @a datablock
-	 * 
+	 *
 	 * This will first lookup the datablock's offset in the index @a index
 	 * and then start parsing from that location until the next datablock.
-	 * 
+	 *
 	 * @param datablock Name of the datablock to parse
 	 * @param index The index created using index_datablocks
 	 * @return true If the datablock was found
@@ -227,12 +348,11 @@ class sac_parser
 
 	/**
 	 * @brief Parse the file
-	 * 
+	 *
 	 */
 	void parse_file();
 
   protected:
-
 	/** @cond */
 
 	sac_parser(std::istream &is, bool init = true);
@@ -245,7 +365,7 @@ class sac_parser
 
 	void error(const std::string &msg)
 	{
-		if (cif::VERBOSE > 0)
+		if (VERBOSE > 0)
 			std::cerr << "Error parsing mmCIF: " << msg << '\n';
 
 		throw parse_error(m_line_nr, msg);
@@ -253,7 +373,7 @@ class sac_parser
 
 	void warning(const std::string &msg)
 	{
-		if (cif::VERBOSE > 0)
+		if (VERBOSE > 0)
 			std::cerr << "parser warning at line " << m_line_nr << ": " << msg << '\n';
 	}
 
@@ -262,10 +382,9 @@ class sac_parser
 	virtual void produce_datablock(std::string_view name) = 0;
 	virtual void produce_category(std::string_view name) = 0;
 	virtual void produce_row() = 0;
-	virtual void produce_item(std::string_view category, std::string_view item, std::string_view value) = 0;
+	virtual void produce_item(std::string_view category, std::string_view item, item_value value) = 0;
 
   protected:
-
 	enum class State
 	{
 		Start,
@@ -281,7 +400,17 @@ class sac_parser
 		TextItem,
 		TextItemNL,
 		Reserved,
-		Value
+		Value,
+
+		TextItemBS,
+		TextItemBS2,
+		TextItemBSNL,
+
+		Numeric_Zero,
+		Numeric_Integer,
+		Numeric_Float,
+		Numeric_Exponent1,
+		Numeric_Exponent2
 	};
 
 	std::streambuf &m_source;
@@ -289,11 +418,15 @@ class sac_parser
 	// Parser state
 	uint32_t m_line_nr;
 	bool m_bol;
+	bool m_backslash_strings = false;
 	CIFToken m_lookahead;
 
 	// token buffer
 	std::vector<char> m_token_buffer;
 	std::string_view m_token_value;
+	int64_t m_token_value_int;
+	double m_token_value_float;
+	int m_float_precision;
 
 	/** @endcond */
 };
@@ -302,7 +435,7 @@ class sac_parser
 
 /**
  * @brief An actual implementation of a sac_parser generating data in a file
- * 
+ *
  * This parser will create the cif::file, cif::datablock and cif::category
  * objects required to contain all data
  */
@@ -331,7 +464,7 @@ class parser : public sac_parser
 
 	void produce_row() override;
 
-	void produce_item(std::string_view category, std::string_view item, std::string_view value) override;
+	void produce_item(std::string_view category, std::string_view item, item_value value) override;
 
   protected:
 	file &m_file;

include/cif++/pdb.hpp

@@ -64,7 +64,7 @@ file read(std::istream &is);
  * @brief Read a file in legacy PDB format from std::istream @a is and
  * put the data into @a cifFile
  */
-file read_pdb_file(std::istream &pdbFile);
+void read_pdb_file(std::istream &pdbFile, cif::file &cifFile);
 
 // mmCIF to PDB
 
@@ -149,6 +149,23 @@ void fixup_pdbx(file &pdbx_file, const validator &v);
 
 bool reconstruct_pdbx(file &pdbx_file, const validator &v);
 
+/** \brief This is an extension to cif::validator, use the logic in common
+ * PDBx files to see if the file is internally consistent.
+ *
+ * This function for now checks if the following categories are consistent:
+ *
+ * atom_site -> pdbx_poly_seq_scheme -> entity_poly_seq -> entity_poly -> entity
+ *
+ * Use the common \ref cif::VERBOSE flag to turn on diagnostic messages.
+ * 
+ * This function throws a std::system_error in case of an error
+ *
+ * \param pdbx_file The input file
+ * \result Returns true if the file was valid and consistent
+ */
+
+bool is_valid_pdbx_file(const file &pdbx_file);
+
 /** \brief This is an extension to cif::validator, use the logic in common
  * PDBx files to see if the file is internally consistent.
  *
@@ -165,8 +182,7 @@ bool reconstruct_pdbx(file &pdbx_file, const validator &v);
  * \result Returns true if the file was valid and consistent
  */
 
-bool is_valid_pdbx_file(const file &pdbx_file,
-	const validator &v = validator_factory::instance().get("mmcif_pdbx.dic"));
+bool is_valid_pdbx_file(const file &pdbx_file, const validator &v);
 
 /** \brief This is an extension to cif::validator, use the logic in common
  * PDBx files to see if the file is internally consistent.
@@ -180,7 +196,8 @@ bool is_valid_pdbx_file(const file &pdbx_file,
  * The dictionary is assumed to be specified in the file or to be the
  * default mmcif_pdbx.dic dictionary.
  *
- * \param file The input file
+ * \param pdbx_file The input file
+ * \param ec In case of error, this will contain what went wrong
  * \result Returns true if the file was valid and consistent
  */
 
@@ -195,7 +212,7 @@ bool is_valid_pdbx_file(const file &pdbx_file, std::error_code &ec);
  *
  * Use the common \ref cif::VERBOSE flag to turn on diagnostic messages.
  * 
- * \param file The input file
+ * \param pdbx_file The input file
  * \param v The validator to use
  * \param ec The error_code in case something was wrong
  * \result Returns true if the file was valid and consistent

include/cif++/pdb/pdb2cif.hpp

@@ -1,32 +0,0 @@
-/*-
- * SPDX-License-Identifier: BSD-2-Clause
- *
- * Copyright (c) 2020 NKI/AVL, Netherlands Cancer Institute
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice, this
- *    list of conditions and the following disclaimer
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- *    this list of conditions and the following disclaimer in the documentation
- *    and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
- * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#pragma once
-
-/// \file pdb2cif.hpp
-/// \deprecated This file is no longer used. Please use "cif++/pdb.hpp" instead
-
-#warning "Use of this file is deprecated, please use "cif++/pdb.hpp"

include/cif++/pdb/tls.hpp

@@ -1,32 +0,0 @@
-/*-
- * SPDX-License-Identifier: BSD-2-Clause
- *
- * Copyright (c) 2020 NKI/AVL, Netherlands Cancer Institute
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice, this
- *    list of conditions and the following disclaimer
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- *    this list of conditions and the following disclaimer in the documentation
- *    and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
- * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#pragma once
-
-/// \file tls.hpp
-/// \deprecated This code has been moved to libpdb-redo
-
-#warning "This code has been moved to libpdb-redo"

include/cif++/point.hpp

@@ -30,15 +30,26 @@
 #include <cmath>
 #include <complex>
 #include <cstdint>
+#include <cstdlib>
+#include <format>
 #include <functional>
+#include <limits>
+#include <numbers>
+#include <optional>
+#include <ostream>
+#include <tuple>
+#include <type_traits>
+#include <utility>
 #include <valarray>
+#include <vector>
 
 #if __has_include(<clipper/core/coords.h>)
-#define HAVE_LIBCLIPPER 1
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wignored-qualifiers"
-#include <clipper/core/coords.h>
-#pragma GCC diagnostic pop
+# define HAVE_LIBCLIPPER 1
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wignored-qualifiers"
+# include <clipper/core/clipper_types.h>
+# include <clipper/core/coords.h>
+# pragma GCC diagnostic pop
 #endif
 
 /** \file point.hpp
@@ -50,12 +61,6 @@
 namespace cif
 {
 
-// --------------------------------------------------------------------
-
-/// \brief Our value for Pi
-const double
-	kPI = 3.141592653589793238462643383279502884;
-
 // --------------------------------------------------------------------
 /**
  * @brief A stripped down quaternion implementation, based on boost::math::quaternion
@@ -117,13 +122,13 @@ class quaternion_type
 	// accessors
 
 	/// \brief See class description, return the *real* part of the quaternion
-	constexpr value_type real() const
+	[[nodiscard]] constexpr value_type real() const
 	{
 		return a;
 	}
 
 	/// \brief See class description, return the *unreal* part of the quaternion
-	constexpr quaternion_type unreal() const
+	[[nodiscard]] constexpr quaternion_type unreal() const
 	{
 		return { 0, b, c, d };
 	}
@@ -152,15 +157,7 @@ class quaternion_type
 	}
 
 	/// \brief Assignment operator
-	constexpr quaternion_type &operator=(quaternion_type const &rhs)
-	{
-		a = rhs.a;
-		b = rhs.b;
-		c = rhs.c;
-		d = rhs.d;
-
-		return *this;
-	}
+	constexpr quaternion_type &operator=(quaternion_type const &rhs) = default;
 
 	/// \brief Assignment operator that sets the *real* part to @a rhs and the *unreal* parts to zero
 	constexpr quaternion_type &operator=(value_type const &rhs)
@@ -273,10 +270,10 @@ class quaternion_type
 	template <typename X>
 	constexpr quaternion_type &operator*=(quaternion_type<X> const &rhs)
 	{
-		value_type ar = static_cast<value_type>(rhs.a);
-		value_type br = static_cast<value_type>(rhs.b);
-		value_type cr = static_cast<value_type>(rhs.c);
-		value_type dr = static_cast<value_type>(rhs.d);
+		auto ar = static_cast<value_type>(rhs.a);
+		auto br = static_cast<value_type>(rhs.b);
+		auto cr = static_cast<value_type>(rhs.c);
+		auto dr = static_cast<value_type>(rhs.d);
 
 		quaternion_type result(a * ar - b * br - c * cr - d * dr, a * br + b * ar + c * dr - d * cr, a * cr - b * dr + c * ar + d * br, a * dr + b * cr - c * br + d * ar);
 		swap(result);
@@ -308,10 +305,10 @@ class quaternion_type
 	template <typename X>
 	constexpr quaternion_type &operator/=(quaternion_type<X> const &rhs)
 	{
-		value_type ar = static_cast<value_type>(rhs.a);
-		value_type br = static_cast<value_type>(rhs.b);
-		value_type cr = static_cast<value_type>(rhs.c);
-		value_type dr = static_cast<value_type>(rhs.d);
+		auto ar = static_cast<value_type>(rhs.a);
+		auto br = static_cast<value_type>(rhs.b);
+		auto cr = static_cast<value_type>(rhs.c);
+		auto dr = static_cast<value_type>(rhs.d);
 
 		value_type denominator = ar * ar + br * br + cr * cr + dr * dr;
 		quaternion_type result((+a * ar + b * br + c * cr + d * dr) / denominator, (-a * br + b * ar - c * dr + d * cr) / denominator, (-a * cr + b * dr + c * ar - d * br) / denominator, (-a * dr - b * cr + c * br + d * ar) / denominator);
@@ -347,10 +344,10 @@ class quaternion_type
 		return quaternion_type{ +q.a, -q.b, -q.c, -q.d };
 	}
 
-	constexpr value_type get_a() const { return a; } ///< Return part a
-	constexpr value_type get_b() const { return b; } ///< Return part b
-	constexpr value_type get_c() const { return c; } ///< Return part c
-	constexpr value_type get_d() const { return d; } ///< Return part d
+	[[nodiscard]] constexpr value_type get_a() const { return a; } ///< Return part a
+	[[nodiscard]] constexpr value_type get_b() const { return b; } ///< Return part b
+	[[nodiscard]] constexpr value_type get_c() const { return c; } ///< Return part c
+	[[nodiscard]] constexpr value_type get_d() const { return d; } ///< Return part d
 
 	/// \brief compare with @a rhs
 	constexpr bool operator==(const quaternion_type &rhs) const
@@ -365,11 +362,18 @@ class quaternion_type
 	}
 
 	/// \brief test for all zero values
-	constexpr operator bool() const
+	constexpr explicit operator bool() const
 	{
 		return a != 0 or b != 0 or c != 0 or d != 0;
 	}
 
+	/// \brief for debugging e.g.
+	friend std::ostream &operator<<(std::ostream &os, const quaternion_type &rhs)
+	{
+		os << std::format("{{ a: {}, b: {}, c: {}, d: {} }}", rhs.a, rhs.b, rhs.c, rhs.d);
+		return os;
+	}
+
   private:
 	value_type a, b, c, d;
 };
@@ -491,17 +495,17 @@ struct point_type
 		return *this;
 	}
 
-	constexpr value_type &get_x() { return m_x; }      ///< Get a reference to x
-	constexpr value_type get_x() const { return m_x; } ///< Get the value of x
-	constexpr void set_x(value_type x) { m_x = x; }    ///< Set the value of x to @a x
+	[[nodiscard]] constexpr value_type &get_x() { return m_x; }      ///< Get a reference to x
+	[[nodiscard]] constexpr value_type get_x() const { return m_x; } ///< Get the value of x
+	constexpr void set_x(value_type x) { m_x = x; }                  ///< Set the value of x to @a x
 
-	constexpr value_type &get_y() { return m_y; }      ///< Get a reference to y
-	constexpr value_type get_y() const { return m_y; } ///< Get the value of y
-	constexpr void set_y(value_type y) { m_y = y; }    ///< Set the value of y to @a y
+	[[nodiscard]] constexpr value_type &get_y() { return m_y; }      ///< Get a reference to y
+	[[nodiscard]] constexpr value_type get_y() const { return m_y; } ///< Get the value of y
+	constexpr void set_y(value_type y) { m_y = y; }                  ///< Set the value of y to @a y
 
-	constexpr value_type &get_z() { return m_z; }      ///< Get a reference to z
-	constexpr value_type get_z() const { return m_z; } ///< Get the value of z
-	constexpr void set_z(value_type z) { m_z = z; }    ///< Set the value of z to @a z
+	[[nodiscard]] constexpr value_type &get_z() { return m_z; }      ///< Get a reference to z
+	[[nodiscard]] constexpr value_type get_z() const { return m_z; } ///< Get the value of z
+	constexpr void set_z(value_type z) { m_z = z; }                  ///< Set the value of z to @a z
 
 	/// \brief add @a rhs
 	constexpr point_type &operator+=(const point_type &rhs)
@@ -682,13 +686,13 @@ struct point_type
 	// consider point as a vector... perhaps I should rename point?
 
 	/// \brief looking at the point as if it is a vector, return the squared length
-	constexpr value_type length_sq() const
+	[[nodiscard]] constexpr value_type length_sq() const
 	{
 		return m_x * m_x + m_y * m_y + m_z * m_z;
 	}
 
 	/// \brief looking at the point as if it is a vector, return the length
-	constexpr value_type length() const
+	[[nodiscard]] constexpr value_type length() const
 	{
 		return std::sqrt(length_sq());
 	}
@@ -743,6 +747,55 @@ inline constexpr auto cross_product(const point_type<F1> &a, const point_type<F2
 		a.m_x * b.m_y - b.m_x * a.m_y);
 }
 
+/// \brief return the squared norm of point @a p
+template <typename F>
+constexpr F norm_squared(const point_type<F> &p)
+{
+	return p.m_x * p.m_x + p.m_y * p.m_y + p.m_z * p.m_z;
+}
+
+/// \brief return the norm of point @a p
+template <typename F>
+constexpr point_type<F> norm(const point_type<F> &p)
+{
+	return std::sqrt(norm_squared(p));
+}
+
+/// \brief return the point where two lines intersect, or an empty value if they don't intersect at all
+template <typename F>
+std::optional<cif::point> line_line_intersection(const point_type<F> &p1,
+	const point_type<F> &p2, const point_type<F> &p3, const point_type<F> &p4)
+{
+	auto p13 = p1 - p3;
+	auto p43 = p4 - p3;
+	if (std::abs(p43.m_x) < std::numeric_limits<F>::epsilon() and std::abs(p43.m_y) < std::numeric_limits<F>::epsilon() and std::abs(p43.m_z) < std::numeric_limits<F>::epsilon())
+		return std::nullopt;
+
+	auto p21 = p2 - p1;
+	if (std::abs(p21.m_x) < std::numeric_limits<F>::epsilon() and std::abs(p21.m_y) < std::numeric_limits<F>::epsilon() and std::abs(p21.m_z) < std::numeric_limits<F>::epsilon())
+		return std::nullopt;
+
+	auto d1343 = cif::dot_product(p43, p13);
+	auto d4321 = cif::dot_product(p43, p21);
+	auto d1321 = cif::dot_product(p13, p21);
+	auto d4343 = cif::dot_product(p43, p43);
+	auto d2121 = cif::dot_product(p21, p21);
+
+	auto denom = d2121 * d4343 - d4321 * d4321;
+	if (std::abs(denom) < std::numeric_limits<F>::epsilon())
+		return std::nullopt;
+
+	auto numer = d1343 * d4321 - d1321 * d4343;
+
+	auto mua = numer / denom;
+	auto mub = (d1343 + d4321 * mua) / d4343;
+
+	auto pa = p1 + mua * p21;
+	auto pb = p3 + mub * p43;
+
+	return { (pa + pb) / 2 };
+}
+
 /// \brief return the angle in degrees between the vectors from point @a p2 to @a p1 and @a p2 to @a p3
 template <typename F>
 constexpr auto angle(const point_type<F> &p1, const point_type<F> &p2, const point_type<F> &p3)
@@ -750,7 +803,7 @@ constexpr auto angle(const point_type<F> &p1, const point_type<F> &p2, const poi
 	point_type<F> v1 = p1 - p2;
 	point_type<F> v2 = p3 - p2;
 
-	return std::acos(dot_product(v1, v2) / (v1.length() * v2.length())) * 180 / kPI;
+	return std::acos(dot_product(v1, v2) / (v1.length() * v2.length())) * 180 / std::numbers::pi_v<F>;
 }
 
 /// \brief return the dihedral angle in degrees for the four points @a p1, @a p2, @a p3 and @a p4
@@ -777,7 +830,7 @@ constexpr auto dihedral_angle(const point_type<F> &p1, const point_type<F> &p2,
 		u = dot_product(p, x) / std::sqrt(u);
 		v = dot_product(p, y) / std::sqrt(v);
 		if (u != 0 or v != 0)
-			result = std::atan2(v, u) * static_cast<F>(180 / kPI);
+			result = std::atan2(v, u) * static_cast<F>(180 / std::numbers::pi_v<F>);
 	}
 
 	return result;
@@ -806,6 +859,9 @@ constexpr auto distance_point_to_line(const point_type<F> &l1, const point_type<
 	return cross.length() / line.length();
 }
 
+/// \brief return the smallest sphere around the points in @a pts
+std::tuple<point, float> smallest_sphere_around_points(std::vector<point> pts);
+
 // --------------------------------------------------------------------
 /**
  * @brief For e.g. simulated annealing, returns a new point that is moved in
@@ -820,7 +876,7 @@ point nudge(point p, float offset);
 quaternion construct_from_angle_axis(float angle, point axis);
 
 /// \brief Return a tuple of an angle and an axis for quaternion @a q
-std::tuple<double, point> quaternion_to_angle_axis(quaternion q);
+std::tuple<float, point> quaternion_to_angle_axis(quaternion q);
 
 /// @brief Given four points and an angle, return the quaternion required to rotate
 /// point p4 along the p2-p3 axis and around point p3 to obtain the required within
@@ -846,74 +902,4 @@ quaternion align_points(const std::vector<point> &a, const std::vector<point> &b
 /// \brief The RMSd for the points in \a a and \a b
 double RMSd(const std::vector<point> &a, const std::vector<point> &b);
 
-// --------------------------------------------------------------------
-/**
- * @brief Helper class to generate evenly divided points on a sphere
- *
- * We use a fibonacci sphere to calculate even distribution of the dots
- *
- * @tparam N The number of points on the sphere is 2 * N + 1
- */
-template <int N>
-class spherical_dots
-{
-  public:
-	/// \brief the number of points
-	constexpr static int P = 2 * N * 1;
-
-	/// \brief the *weight* of the fibonacci sphere
-	constexpr static double W = (4 * kPI) / P;
-
-	/// \brief the internal storage type
-	using array_type = typename std::array<point, P>;
-
-	/// \brief iterator type
-	using iterator = typename array_type::const_iterator;
-
-	/// \brief singleton instance
-	static spherical_dots &instance()
-	{
-		static spherical_dots sInstance;
-		return sInstance;
-	}
-
-	/// \brief The number of points
-	std::size_t size() const { return P; }
-
-	/// \brief Access a point by index
-	const point operator[](uint32_t inIx) const { return m_points[inIx]; }
-
-	/// \brief iterator pointing to the first point
-	iterator begin() const { return m_points.begin(); }
-
-	/// \brief iterator pointing past the last point
-	iterator end() const { return m_points.end(); }
-
-	/// \brief return the *weight*,
-	double weight() const { return W; }
-
-	spherical_dots()
-	{
-		const double
-			kGoldenRatio = (1 + std::sqrt(5.0)) / 2;
-
-		auto p = m_points.begin();
-
-		for (int32_t i = -N; i <= N; ++i)
-		{
-			double lat = std::asin((2.0 * i) / P);
-			double lon = std::fmod(i, kGoldenRatio) * 2 * kPI / kGoldenRatio;
-
-			p->m_x = std::sin(lon) * std::cos(lat);
-			p->m_y = std::cos(lon) * std::cos(lat);
-			p->m_z = std::sin(lat);
-
-			++p;
-		}
-	}
-
-  private:
-	array_type m_points;
-};
-
 } // namespace cif

include/cif++/row.hpp

@@ -29,66 +29,441 @@
 #include "cif++/item.hpp"
 
 #include <array>
+#include <cstddef>
+#include <cstdint>
+#include <initializer_list>
+#include <string>
+#include <string_view>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+#include <vector>
 
 /**
  * @file row.hpp
- * 
+ *
  * The class cif::row should be an opaque type. It is used to store the
  * internal data per row in a category. You should use cif::row_handle
  * to get access to the contents in a row.
- * 
+ *
  * One could think of rows as vectors of cif::item. But internally
  * that's not the case.
- * 
+ *
  * You can access the values of stored items by name or index.
- * The return value of operator[] is an cif::item_handle object.
- * 
+ * The return value of operator[] is a reference to a cif::item_value object.
+ *
  * @code {.cpp}
  * cif::category &atom_site = my_db["atom_site"];
  * cif::row_handle rh = atom_site.front();
- * 
+ *
  * // by name:
- * std::string name = rh["label_atom_id"].as<std::string>();
- * 
+ * std::string name = rh["label_atom_id"].get<std::string>();
+ *
  * // by index:
  * uint16_t ix = atom_site.get_item_ix("label_atom_id");
- * assert(rh[ix].as<std::string() == name);
+ * assert(rh[ix].get<std::string() == name);
  * @endcode
- * 
+ *
  * There some template magic here to allow easy extracting of data
  * from rows. This can be done using cif::tie e.g.:
- * 
+ *
  * @code {.cpp}
  * std::string name;
  * float x, y, z;
- * 
+ *
  * cif::tie(name, x, y, z) = rh.get("label_atom_id", "cartn_x", "cartn_y", "cartn_z");
  * @endcode
- * 
+ *
  * However, a more modern way uses structured binding:
- * 
+ *
  * @code {.cpp}
  * const auto &[name, x, y, z] = rh.get<std::string,float,float,float>("label_atom_id", "cartn_x", "cartn_y", "cartn_z");
  * @endcode
- * 
- * 
- * 
+ *
+ *
+ *
  */
 
 namespace cif
 {
 
+class category;
+
+namespace cql
+{
+	struct connection_impl;
+}
+
 namespace detail
 {
+	template <typename... C>
+	struct get_row_result;
+}
 
-	// some helper classes to help create tuple result types
+// --------------------------------------------------------------------
+/// \brief the row class, this one is not directly accessible from the outside
+
+class row : public std::vector<item_value>
+{
+  public:
+	row() = default;
+
+  private:
+	/**
+	 * @brief Return the item_value pointer for item at index @a ix
+	 */
+	item_value *get(uint16_t ix)
+	{
+		if (ix >= size())
+			resize(ix + 1);
+		return &data()[ix];
+	}
+
+	/**
+	 * @brief Return the const item_value pointer for item at index @a ix
+	 */
+	[[nodiscard]] const item_value *get(uint16_t ix) const
+	{
+		return ix < size() ? &data()[ix] : nullptr;
+	}
+
+	void set(uint16_t ix, item_value v)
+	{
+		if (ix >= size())
+			resize(ix + 1);
+		operator[](ix) = std::move(v);
+	}
+
+	friend class category;
+	friend class category_index;
+
+	template <bool, typename...>
+	friend class iterator_impl_base;
+
+	row *m_next = nullptr;
+};
+
+// --------------------------------------------------------------------
+/// \brief row_handle is the way to access data stored in rows
+
+class row_handle
+{
+  public:
+	/** @cond */
+	template <bool>
+	friend struct item_handle_base;
+	friend class category;
+	friend class category_index;
+	friend class row_initializer;
+	friend class const_row_handle;
+
+	template <bool, typename...>
+	friend class iterator_impl_base;
+
+	row_handle() = default;
+	virtual ~row_handle() = default;
+
+	row_handle(const row_handle &) = default;
+	row_handle(row_handle &&) = default;
+	row_handle &operator=(const row_handle &) = default;
+	row_handle &operator=(row_handle &&) = default;
+
+	/** @endcond */
+
+	/// \brief constructor taking a category @a cat and a row @a r
+	row_handle(category &cat, row &r)
+		: m_category(&cat)
+		, m_row(&r)
+	{
+	}
+
+	/// \brief return the category this row belongs to
+	[[nodiscard]] category &get_category() const
+	{
+		return *m_category;
+	}
+
+	/// \brief return the row ID
+	[[nodiscard]] int64_t row_id() const
+	{
+		return reinterpret_cast<int64_t>(m_row);
+	}
+
+	/// \brief Return true if the row is empty or uninitialised
+	[[nodiscard]] bool empty() const
+	{
+		return m_category == nullptr or m_row == nullptr;
+	}
+
+	/// \brief convenience method to test for empty()
+	explicit operator bool() const
+	{
+		return not empty();
+	}
+
+	/// \brief return the count of the items
+	[[nodiscard]] size_t size() const { return m_row->size(); }
+
+	/// \brief return a cif::item_handle to the item in item @a item_ix
+	item_handle operator[](uint16_t item_ix)
+	{
+		return { *m_category, *m_row, item_ix };
+	}
+
+	/// \brief return a cif::item_handle to the item in item @a item_ix
+	const item_handle operator[](uint16_t item_ix) const
+	{
+		return { *m_category, *m_row, item_ix };
+	}
+
+	/// \brief return a cif::item_handle to the item in the item named @a item_name
+	item_handle operator[](std::string_view item_name)
+	{
+		return { *m_category, *m_row, add_item(item_name) };
+	}
+
+	/// \brief return a cif::item_handle to the item in the item named @a item_name
+	const item_handle operator[](std::string_view item_name) const
+	{
+		return { *m_category, *m_row, get_item_ix(item_name) };
+	}
+
+	/// \brief assign each of the items named in @a values to their respective value
+	void assign(const std::vector<item> &values, bool updateLinked = true)
+	{
+		for (auto &value : values)
+			assign(value, updateLinked);
+	}
+
+	/** \brief assign the value @a value to the item named @a name
+	 *
+	 * If updateLinked it true, linked records are updated as well.
+	 * That means that if item @a name is part of the link definition
+	 * and the link results in a linked record in another category
+	 * this record in the linked category is updated as well.
+	 *
+	 * If validate is true, which is default, the assigned value is
+	 * checked to see if it conforms to the rules defined in the dictionary
+	 */
+
+	void assign(std::string_view name, item_value value, bool updateLinked, bool validate = true)
+	{
+		assign(add_item(name), std::move(value), updateLinked, validate);
+	}
+
+	/** \brief assign the value @a value to item at index @a item
+	 *
+	 * If updateLinked it true, linked records are updated as well.
+	 * That means that if item @a item is part of the link definition
+	 * and the link results in a linked record in another category
+	 * this record in the linked category is updated as well.
+	 *
+	 * If validate is true, which is default, the assigned value is
+	 * checked to see if it conforms to the rules defined in the dictionary
+	 */
+
+	void assign(uint16_t item, item_value value, bool updateLinked, bool validate = true);
+
+	/// \brief Return an object that can be used in combination with cif::tie
+	/// to assign the values for the items @a items
+	template <typename... C>
+	[[nodiscard]] auto get(C... items) const
+	{
+		return detail::get_row_result<C...>(*this, { get_item_ix(items)... });
+	}
+
+	/// \brief Return a tuple of values of types @a Ts for the items @a items
+	template <typename... Ts, typename... C>
+	std::tuple<Ts...> get(C... items) const
+		requires(sizeof...(Ts) == sizeof...(C) and sizeof...(C) != 1)
+	{
+		return detail::get_row_result<Ts...>(*this, { get_item_ix(items)... });
+	}
+
+	/// \brief Get the value of item @a item cast to type @a T
+	template <typename T>
+	[[nodiscard]] T get(std::string_view item) const
+	{
+		return operator[](get_item_ix(item)).template get<T>();
+	}
+
+	/// \brief compare two rows
+	bool operator==(const row_handle &rhs) const { return m_category == rhs.m_category and m_row == rhs.m_row; }
+
+	/// \brief compare two rows
+	bool operator!=(const row_handle &rhs) const { return m_category != rhs.m_category or m_row != rhs.m_row; }
+
+  protected:
+	/// Return the index number for the item named @a name
+	[[nodiscard]] uint16_t get_item_ix(std::string_view name) const;
+
+	/// Return the name for the item with index number @a ix
+	[[nodiscard]] std::string_view get_item_name(uint16_t ix) const;
+
+	friend cql::connection_impl;
+
+	/// Return the actual row
+	[[nodiscard]] auto get_row() const
+	{
+		return m_row;
+	}
+
+	category *m_category = nullptr; ///< The category
+	row *m_row = nullptr;           ///< The row
+
+  private:
+	/// @cond
+	uint16_t add_item(std::string_view name);
+
+	void assign(const item &i, bool updateLinked)
+	{
+		assign(i.name(), i.value(), updateLinked);
+	}
+
+	/// @endcond
+};
+
+/// A const version of row_handle.
+
+class const_row_handle
+{
+  public:
+	/** @cond */
+	template <bool>
+	friend struct item_handle_base;
+	friend class category;
+	friend class category_index;
+	friend class row_initializer;
+
+	template <bool, typename...>
+	friend class iterator_impl_base;
+
+	const_row_handle() = default;
+	virtual ~const_row_handle() = default;
+
+	const_row_handle(const const_row_handle &) = default;
+	const_row_handle(const_row_handle &&) = default;
+	const_row_handle &operator=(const const_row_handle &) = default;
+	const_row_handle &operator=(const_row_handle &&) = default;
+
+	const_row_handle(row_handle rh)
+		: m_category(rh.m_category)
+		, m_row(rh.m_row)
+	{
+	}
+
+	/** @endcond */
+
+	/// \brief constructor taking a category @a cat and a row @a r
+	const_row_handle(const category &cat, const row &r)
+		: m_category(&cat)
+		, m_row(&r)
+	{
+	}
+
+	/// \brief return the category this row belongs to
+	[[nodiscard]] const category &get_category() const
+	{
+		return *m_category;
+	}
+
+	/// \brief return the row ID
+	[[nodiscard]] int64_t row_id() const
+	{
+		return reinterpret_cast<int64_t>(m_row);
+	}
+
+	/// \brief Return true if the row is empty or uninitialised
+	[[nodiscard]] bool empty() const
+	{
+		return m_category == nullptr or m_row == nullptr;
+	}
+
+	/// \brief convenience method to test for empty()
+	explicit operator bool() const
+	{
+		return not empty();
+	}
+
+	/// \brief return the count of the items
+	[[nodiscard]] size_t size() const { return m_row->size(); }
+
+	/// \brief return a cif::item_handle to the item in item @a item_ix
+	const item_handle operator[](uint16_t item_ix) const
+	{
+		return { *m_category, *m_row, item_ix };
+	}
+
+	/// \brief return a cif::item_handle to the item in the item named @a item_name
+	const item_handle operator[](std::string_view item_name) const
+	{
+		return operator[](get_item_ix(item_name));
+	}
+
+	/// \brief Return an object that can be used in combination with cif::tie
+	/// to assign the values for the items @a items
+	template <typename... C>
+	[[nodiscard]] auto get(C... items) const
+	{
+		return detail::get_row_result<C...>(*this, { get_item_ix(items)... });
+	}
+
+	/// \brief Return a tuple of values of types @a Ts for the items @a items
+	template <typename... Ts, typename... C>
+	std::tuple<Ts...> get(C... items) const
+		requires(sizeof...(Ts) == sizeof...(C) and sizeof...(C) != 1)
+	{
+		return detail::get_row_result<Ts...>(*this, { get_item_ix(items)... });
+	}
+
+	/// \brief Get the value of item @a item cast to type @a T
+	template <typename T>
+	[[nodiscard]] T get(std::string_view item) const
+	{
+		return operator[](get_item_ix(item)).template get<T>();
+	}
+
+	/// \brief compare two rows
+	// bool operator==(const const_row_handle &rhs) const { return m_category == rhs.m_category and m_row == rhs.m_row; }
+	friend bool operator==(const_row_handle a, const_row_handle b)
+	{
+		return a.m_category == b.m_category and a.m_row == b.m_row;
+	}
+
+	/// \brief compare two rows
+	bool operator!=(const const_row_handle &rhs) const { return m_category != rhs.m_category or m_row != rhs.m_row; }
+
+  protected:
+	/// Return the index number for the item named @a name
+	[[nodiscard]] uint16_t get_item_ix(std::string_view name) const;
+
+	/// Return the name for the item with index number @a ix
+	[[nodiscard]] std::string_view get_item_name(uint16_t ix) const;
+
+	friend cql::connection_impl;
+
+	/// Return the actual row
+	[[nodiscard]] auto get_row() const
+	{
+		return m_row;
+	}
+
+	const category *m_category = nullptr; ///< The category
+	const row *m_row = nullptr;           ///< The row
+};
+
+namespace detail
+{
+	/// @cond
+
+	/// some helper classes to help create tuple result types
 	template <typename... C>
 	struct get_row_result
 	{
 		static constexpr std::size_t N = sizeof...(C);
 
-		get_row_result(const row_handle &r, std::array<uint16_t, N> &&items)
-			: m_row(r)
+		get_row_result(const_row_handle r, std::array<uint16_t, N> &&items)
+			: m_row(std::move(r))
 			, m_items(std::move(items))
 		{
 		}
@@ -98,19 +473,20 @@ namespace detail
 			return m_row[m_items[ix]];
 		}
 
-		template <typename... Ts, std::enable_if_t<N == sizeof...(Ts), int> = 0>
+		template <typename... Ts>
 		operator std::tuple<Ts...>() const
+			requires(N == sizeof...(Ts))
 		{
 			return get<Ts...>(std::index_sequence_for<Ts...>{});
 		}
 
 		template <typename... Ts, std::size_t... Is>
-		std::tuple<Ts...> get(std::index_sequence<Is...>) const
+		[[nodiscard]] std::tuple<Ts...> get(std::index_sequence<Is...>) const
 		{
-			return std::tuple<Ts...>{ m_row[m_items[Is]].template as<Ts>()... };
+			return std::tuple<Ts...>{ m_row[m_items[Is]].template get<Ts>()... };
 		}
 
-		const row_handle &m_row;
+		const_row_handle m_row;
 		std::array<uint16_t, N> m_items;
 	};
 
@@ -131,7 +507,7 @@ namespace detail
 			// of the row should be equal to the number of items in the tuple
 			// you are trying to tie.
 
-			using RType = std::tuple<typename std::remove_reference<Ts>::type...>;
+			using RType = std::tuple<std::remove_reference_t<Ts>...>;
 
 			m_value = static_cast<RType>(rr);
 		}
@@ -139,9 +515,11 @@ namespace detail
 		std::tuple<Ts...> m_value;
 	};
 
+	/// @endcond
+
 } // namespace detail
 
-/// \brief similar to std::tie, assign values to each element in @a v from the 
+/// \brief similar to std::tie, assign values to each element in @a v from the
 /// result of a get on a row_handle.
 template <typename... Ts>
 auto tie(Ts &...v)
@@ -149,229 +527,11 @@ auto tie(Ts &...v)
 	return detail::tie_wrap<Ts &...>(std::forward<Ts &>(v)...);
 }
 
-// --------------------------------------------------------------------
-/// \brief the row class, this one is not directly accessible from the outside
-
-class row : public std::vector<item_value>
-{
-  public:
-	row() = default;
-
-	/**
-	 * @brief Return the item_value pointer for item at index @a ix
-	 */
-	item_value* get(uint16_t ix)
-	{
-		return ix < size() ? &data()[ix] : nullptr;
-	}
-
-	/**
-	 * @brief Return the const item_value pointer for item at index @a ix
-	 */
-	const item_value* get(uint16_t ix) const
-	{
-		return ix < size() ? &data()[ix] : nullptr;
-	}
-
-  private:
-	friend class category;
-	friend class category_index;
-
-	template <typename, typename...>
-	friend class iterator_impl;
-
-	void append(uint16_t ix, item_value &&iv)
-	{
-		if (ix >= size())
-			resize(ix + 1);
-		
-		at(ix) = std::move(iv);
-	}
-
-	void remove(uint16_t ix)
-	{
-		if (ix < size())
-			at(ix) = item_value{};
-	}
-
-	row *m_next = nullptr;
-};
-
-// --------------------------------------------------------------------
-/// \brief row_handle is the way to access data stored in rows
-
-class row_handle
-{
-  public:
-	/** @cond */
-	friend struct item_handle;
-	friend class category;
-	friend class category_index;
-	friend class row_initializer;
-	template <typename, typename...> friend class iterator_impl;
-
-	row_handle() = default;
-
-	row_handle(const row_handle &) = default;
-	row_handle(row_handle &&) = default;
-
-	row_handle &operator=(const row_handle &) = default;
-	row_handle &operator=(row_handle &&) = default;
-
-	/** @endcond */
-
-	/// \brief constructor taking a category @a cat and a row @a r
-	row_handle(const category &cat, const row &r)
-		: m_category(const_cast<category *>(&cat))
-		, m_row(const_cast<row *>(&r))
-	{
-	}
-
-	/// \brief return the category this row belongs to
-	const category &get_category() const
-	{
-		return *m_category;
-	}
-
-	/// \brief Return true if the row is empty or uninitialised
-	bool empty() const
-	{
-		return m_category == nullptr or m_row == nullptr;
-	}
-
-	/// \brief convenience method to test for empty()
-	explicit operator bool() const
-	{
-		return not empty();
-	}
-
-	/// \brief return a cif::item_handle to the item in item @a item_ix
-	item_handle operator[](uint16_t item_ix)
-	{
-		return empty() ? item_handle::s_null_item : item_handle(item_ix, *this);
-	}
-
-	/// \brief return a const cif::item_handle to the item in item @a item_ix
-	const item_handle operator[](uint16_t item_ix) const
-	{
-		return empty() ? item_handle::s_null_item : item_handle(item_ix, const_cast<row_handle &>(*this));
-	}
-
-	/// \brief return a cif::item_handle to the item in the item named @a item_name
-	item_handle operator[](std::string_view item_name)
-	{
-		return empty() ? item_handle::s_null_item : item_handle(add_item(item_name), *this);
-	}
-
-	/// \brief return a const cif::item_handle to the item in the item named @a item_name
-	const item_handle operator[](std::string_view item_name) const
-	{
-		return empty() ? item_handle::s_null_item : item_handle(get_item_ix(item_name), const_cast<row_handle &>(*this));
-	}
-
-	/// \brief Return an object that can be used in combination with cif::tie
-	/// to assign the values for the items @a items
-	template <typename... C>
-	auto get(C... items) const
-	{
-		return detail::get_row_result<C...>(*this, { get_item_ix(items)... });
-	}
-
-	/// \brief Return a tuple of values of types @a Ts for the items @a items
-	template <typename... Ts, typename... C, std::enable_if_t<sizeof...(Ts) == sizeof...(C) and sizeof...(C) != 1, int> = 0>
-	std::tuple<Ts...> get(C... items) const
-	{
-		return detail::get_row_result<Ts...>(*this, { get_item_ix(items)... });
-	}
-
-	/// \brief Get the value of item @a item cast to type @a T
-	template <typename T>
-	T get(const char *item) const
-	{
-		return operator[](get_item_ix(item)).template as<T>();
-	}
-
-	/// \brief Get the value of item @a item cast to type @a T
-	template <typename T>
-	T get(std::string_view item) const
-	{
-		return operator[](get_item_ix(item)).template as<T>();
-	}
-
-	/// \brief assign each of the items named in @a values to their respective value
-	void assign(const std::vector<item> &values)
-	{
-		for (auto &value : values)
-			assign(value, true);
-	}
-
-	/** \brief assign the value @a value to the item named @a name 
-	 * 
-	 * If updateLinked it true, linked records are updated as well.
-	 * That means that if item @a name is part of the link definition
-	 * and the link results in a linked record in another category
-	 * this record in the linked category is updated as well.
-	 * 
-	 * If validate is true, which is default, the assigned value is
-	 * checked to see if it conforms to the rules defined in the dictionary
-	 */
-
-	void assign(std::string_view name, std::string_view value, bool updateLinked, bool validate = true)
-	{
-		assign(add_item(name), value, updateLinked, validate);
-	}
-
-	/** \brief assign the value @a value to item at index @a item
-	 * 
-	 * If updateLinked it true, linked records are updated as well.
-	 * That means that if item @a item is part of the link definition
-	 * and the link results in a linked record in another category
-	 * this record in the linked category is updated as well.
-	 * 
-	 * If validate is true, which is default, the assigned value is
-	 * checked to see if it conforms to the rules defined in the dictionary
-	 */
-
-	void assign(uint16_t item, std::string_view value, bool updateLinked, bool validate = true);
-
-	/// \brief compare two rows
-	bool operator==(const row_handle &rhs) const { return m_category == rhs.m_category and m_row == rhs.m_row; }
-
-	/// \brief compare two rows
-	bool operator!=(const row_handle &rhs) const { return m_category != rhs.m_category or m_row != rhs.m_row; }
-
-  private:
-	uint16_t get_item_ix(std::string_view name) const;
-	std::string_view get_item_name(uint16_t ix) const;
-
-	uint16_t add_item(std::string_view name);
-
-	row *get_row()
-	{
-		return m_row;
-	}
-
-	const row *get_row() const
-	{
-		return m_row;
-	}
-
-	void assign(const item &i, bool updateLinked)
-	{
-		assign(i.name(), i.value(), updateLinked);
-	}
-
-	void swap(uint16_t item, row_handle &r);
-
-	category *m_category = nullptr;
-	row *m_row = nullptr;
-};
-
 // --------------------------------------------------------------------
 
 /**
  * @brief The class row_initializer is a list of cif::item's.
- * 
+ *
  * This class is used to construct new rows, it allows to
  * group a list of item name and value pairs and pass it
  * in one go to the constructing function.
@@ -397,18 +557,24 @@ class row_initializer : public std::vector<item>
 	}
 
 	/// \brief constructor taking a range of items
-	template <typename ItemIter, std::enable_if_t<std::is_same_v<typename ItemIter::value_type, item>, int> = 0>
+	template <typename ItemIter>
 	row_initializer(ItemIter b, ItemIter e)
+		requires(std::is_constructible_v<item, typename ItemIter::value_type>)
 		: std::vector<item>(b, e)
 	{
 	}
 
 	/// \brief constructor taking the values of an existing row
-	row_initializer(row_handle rh);
+	row_initializer(row_handle rh)
+		: cif::row_initializer(const_row_handle{ rh })
+	{
+	}
 
+	/// Constructor
+	row_initializer(const_row_handle rh);
 
 	/// \brief set the value for item name @a name to @a value
-	void set_value(std::string_view name, std::string_view value);
+	void set_value(std::string name, item_value value);
 
 	/// \brief set the value for item based on @a i
 	void set_value(const item &i)
@@ -417,13 +583,19 @@ class row_initializer : public std::vector<item>
 	}
 
 	/// \brief set the value for item name @a name to @a value, but only if the item did not have a value already
-	void set_value_if_empty(std::string_view name, std::string_view value);
+	void set_value_if_empty(std::string name, item_value value);
 
 	/// \brief set the value for item @a i, but only if the item did not have a value already
 	void set_value_if_empty(const item &i)
 	{
 		set_value_if_empty(i.name(), i.value());
 	}
+
+	/// \brief enable emplace_back for more complex items (floats with precission)
+	auto emplace_back(std::string name, item_value value)
+	{
+		return std::vector<item>::emplace_back(item(std::forward<std::string>(name), std::forward<item_value>(value)));
+	}
 };
 
-} // namespace cif
+} // namespace cif

include/cif++/symmetry.hpp

@@ -35,7 +35,7 @@
 #include <string>
 
 #if defined(__cpp_impl_three_way_comparison)
-#include <compare>
+# include <utility>
 #endif
 
 /** \file cif++/symmetry.hpp
@@ -95,7 +95,7 @@ extern CIFPP_EXPORT const std::size_t kNrOfSpaceGroups;
 struct symop_data
 {
 	/// \brief constructor
-	constexpr symop_data(const std::array<int, 15> &data)
+	constexpr symop_data(const std::array<int, 15> &data) noexcept
 		: m_packed((data[0] bitand 0x03ULL) << 34 bitor
 				   (data[1] bitand 0x03ULL) << 32 bitor
 				   (data[2] bitand 0x03ULL) << 30 bitor
@@ -127,20 +127,20 @@ struct symop_data
 	}
 
 	/// \brief return an int representing the value stored in the two bits at offset @a offset
-	inline constexpr int unpack3(int offset) const
+	[[nodiscard]] inline constexpr int unpack3(int offset) const
 	{
-		int result = (m_packed >> offset) bitand 0x03;
+		int result = static_cast<int>((m_packed >> offset) bitand 0x03);
 		return result == 3 ? -1 : result;
 	}
 
 	/// \brief return an int representing the value stored in the three bits at offset @a offset
-	inline constexpr int unpack7(int offset) const
+	[[nodiscard]] inline constexpr int unpack7(int offset) const
 	{
-		return (m_packed >> offset) bitand 0x07;
+		return static_cast<int>((m_packed >> offset) bitand 0x07);
 	}
 
 	/// \brief return an array of 15 ints representing the values stored
-	constexpr std::array<int, 15> data() const
+	[[nodiscard]] constexpr std::array<int, 15> data() const
 	{
 		return {
 			unpack3(34),
@@ -182,16 +182,16 @@ struct symop_data
 struct symop_datablock
 {
 	/// \brief constructor
-	constexpr symop_datablock(int spacegroup, int rotational_number, const std::array<int, 15> &rt_data)
+	constexpr symop_datablock(int spacegroup, int rotational_number, const std::array<int, 15> &rt_data) noexcept
 		: m_v((spacegroup bitand 0xffffULL) << 48 bitor
 			  (rotational_number bitand 0xffULL) << 40 bitor
 			  symop_data(rt_data).m_packed)
 	{
 	}
 
-	uint16_t spacegroup() const { return m_v >> 48; }                     ///< Return the spacegroup
-	symop_data symop() const { return symop_data(m_v); }                  ///< Return the symmetry operation
-	uint8_t rotational_number() const { return (m_v >> 40) bitand 0xff; } ///< Return the rotational_number
+	[[nodiscard]] int spacegroup() const { return m_v >> 48; }                          ///< Return the spacegroup
+	[[nodiscard]] symop_data symop() const { return { m_v }; }                          ///< Return the symmetry operation
+	[[nodiscard]] uint8_t rotational_number() const { return (m_v >> 40) bitand 0xff; } ///< Return the rotational_number
 
   private:
 	uint64_t m_v;
@@ -249,7 +249,7 @@ struct sym_op
 	/** @endcond */
 
 	/// \brief return true if this sym_op is the identity operator
-	constexpr bool is_identity() const
+	[[nodiscard]] constexpr bool is_identity() const
 	{
 		return m_nr == 1 and m_ta == 5 and m_tb == 5 and m_tc == 5;
 	}
@@ -261,7 +261,7 @@ struct sym_op
 	}
 
 	/// \brief return the content encoded in a string
-	std::string string() const;
+	[[nodiscard]] std::string string() const;
 
 #if defined(__cpp_impl_three_way_comparison)
 	/// \brief a default spaceship operator
@@ -389,18 +389,18 @@ class cell
 	/// \brief constructor that takes the appropriate values from the *cell* category in datablock @a db
 	cell(const datablock &db);
 
-	float get_a() const { return m_a; } ///< return dimension a
-	float get_b() const { return m_b; } ///< return dimension b
-	float get_c() const { return m_c; } ///< return dimension c
+	[[nodiscard]] float get_a() const { return m_a; } ///< return dimension a
+	[[nodiscard]] float get_b() const { return m_b; } ///< return dimension b
+	[[nodiscard]] float get_c() const { return m_c; } ///< return dimension c
 
-	float get_alpha() const { return m_alpha; } ///< return angle alpha
-	float get_beta() const { return m_beta; }   ///< return angle beta
-	float get_gamma() const { return m_gamma; } ///< return angle gamma
+	[[nodiscard]] float get_alpha() const { return m_alpha; } ///< return angle alpha
+	[[nodiscard]] float get_beta() const { return m_beta; }   ///< return angle beta
+	[[nodiscard]] float get_gamma() const { return m_gamma; } ///< return angle gamma
 
-	float get_volume() const; ///< return the calculated volume for this cell
+	[[nodiscard]] float get_volume() const; ///< return the calculated volume for this cell
 
-	matrix3x3<float> get_orthogonal_matrix() const { return m_orthogonal; } ///< return the matrix to use to transform coordinates from fractional to orthogonal
-	matrix3x3<float> get_fractional_matrix() const { return m_fractional; } ///< return the matrix to use to transform coordinates from orthogonal to fractional
+	[[nodiscard]] matrix3x3<float> get_orthogonal_matrix() const { return m_orthogonal; } ///< return the matrix to use to transform coordinates from fractional to orthogonal
+	[[nodiscard]] matrix3x3<float> get_fractional_matrix() const { return m_fractional; } ///< return the matrix to use to transform coordinates from orthogonal to fractional
 
   private:
 	void init();
@@ -448,8 +448,8 @@ class spacegroup : public std::vector<transformation>
 	/// \brief constructor using the spacegroup number @a nr
 	spacegroup(int nr);
 
-	int get_nr() const { return m_nr; } ///< Return the nr
-	std::string get_name() const;       ///< Return the name
+	[[nodiscard]] int get_nr() const { return m_nr; } ///< Return the nr
+	[[nodiscard]] std::string get_name() const;       ///< Return the name
 
 	/** \brief perform a spacegroup operation on point @a pt using
 	 * cell @a c and sym_op @a symop
@@ -460,7 +460,7 @@ class spacegroup : public std::vector<transformation>
 	/** \brief perform an inverse spacegroup operation on point @a pt using
 	 * cell @a c and sym_op @a symop
 	 */
-	point inverse(const point &pt, const cell &c, sym_op symop) const;
+	[[nodiscard]] point inverse(const point &pt, const cell &c, sym_op symop) const;
 
   private:
 	int m_nr;
@@ -486,9 +486,9 @@ class crystal
 	}
 
 	/// \brief constructor using cell @a c and spacegroup @a sg
-	crystal(const cell &c, const spacegroup &sg)
+	crystal(const cell &c, spacegroup sg)
 		: m_cell(c)
-		, m_spacegroup(sg)
+		, m_spacegroup(std::move(sg))
 	{
 	}
 
@@ -499,24 +499,24 @@ class crystal
 	crystal &operator=(crystal &&) = default;
 	/** @endcond */
 
-	const cell &get_cell() const { return m_cell; }                   ///< Return the cell
-	const spacegroup &get_spacegroup() const { return m_spacegroup; } ///< Return the spacegroup
+	[[nodiscard]] const cell &get_cell() const { return m_cell; }                   ///< Return the cell
+	[[nodiscard]] const spacegroup &get_spacegroup() const { return m_spacegroup; } ///< Return the spacegroup
 
 	/// \brief Return the symmetry copy of point @a pt using symmetry operation @a symop
-	point symmetry_copy(const point &pt, sym_op symop) const
+	[[nodiscard]] point symmetry_copy(const point &pt, sym_op symop) const
 	{
 		return m_spacegroup(pt, m_cell, symop);
 	}
 
 	/// \brief Return the symmetry copy of point @a pt using the inverse of symmetry operation @a symop
-	point inverse_symmetry_copy(const point &pt, sym_op symop) const
+	[[nodiscard]] point inverse_symmetry_copy(const point &pt, sym_op symop) const
 	{
 		return m_spacegroup.inverse(pt, m_cell, symop);
 	}
 
 	/// \brief Return a tuple consisting of distance, new location and symmetry operation
 	/// for the point @a b with respect to point @a a.
-	std::tuple<float, point, sym_op> closest_symmetry_copy(point a, point b) const;
+	[[nodiscard]] std::tuple<float, point, sym_op> closest_symmetry_copy(point a, point b) const;
 
   private:
 	cell m_cell;

include/cif++/text.hpp

@@ -29,22 +29,27 @@
 #include "cif++/exports.hpp"
 
 #include <charconv>
-#include <cmath>
+#include <cstddef>
 #include <cstdint>
-#include <limits>
+#include <iterator>
 #include <set>
 #include <sstream>
+#include <string>
+#include <string_view>
 #include <tuple>
+#include <type_traits>
+#include <utility>
 #include <vector>
 
 #if __has_include(<experimental/type_traits>)
 
-#include <experimental/type_traits>
+# include <experimental/type_traits>
 namespace std_experimental = std::experimental;
 
 #else
 
 // A quick hack to work around the missing is_detected in MSVC
+/// @cond
 namespace std_experimental
 {
 
@@ -69,6 +74,7 @@ using is_detected = typename detail::detector<void, Op, Args...>::value_t;
 template <template <class...> class Op, class... Args>
 const auto is_detected_v = is_detected<Op, Args...>::value;
 
+/// @endcond
 } // namespace std_experimental
 
 #endif
@@ -88,16 +94,16 @@ namespace cif
 // our own case conversion routines.
 
 /// \brief return whether string @a is equal to string @a b ignoring changes in character case
-bool iequals(std::string_view a, std::string_view b);
+bool iequals(std::string_view a, std::string_view b) noexcept;
 
 /// \brief compare string @a is to string @a b ignoring changes in character case
-int icompare(std::string_view a, std::string_view b);
+int icompare(std::string_view a, std::string_view b) noexcept;
 
 /// \brief return whether string @a is equal to string @a b ignoring changes in character case
-bool iequals(const char *a, const char *b);
+bool iequals(const char *a, const char *b) noexcept;
 
 /// \brief compare string @a is to string @a b ignoring changes in character case
-int icompare(const char *a, const char *b);
+int icompare(const char *a, const char *b) noexcept;
 
 /// \brief convert the string @a s to lower case in situ
 void to_lower(std::string &s);
@@ -328,7 +334,6 @@ inline char tolower(int ch)
 [[deprecated("use split_item_name instead")]]
 std::tuple<std::string, std::string> split_tag_name(std::string_view item_name);
 
-
 /** \brief return a tuple consisting of the category and item name for @a item_name
  *
  * The category name is stripped of its leading underscore character.
@@ -355,279 +360,40 @@ std::string cif_id_for_number(int number);
 std::vector<std::string> word_wrap(const std::string &text, std::size_t width);
 
 // --------------------------------------------------------------------
-/// \brief std::from_chars for floating point types.
-///
-/// These are optional, there's a selected_charconv class below that selects
-/// the best option to use based on support by the stl library.
-///
-/// I.e. that in case of GNU < 12 (or something) the cif implementation will
-/// be used, all other cases will use the stl version.
 
-template <typename FloatType, std::enable_if_t<std::is_floating_point_v<FloatType>, int> = 0>
-std::from_chars_result from_chars(const char *first, const char *last, FloatType &value)
-{
-	std::from_chars_result result{ first, {} };
+/// @cond
+// Code to select a version of from_chars that is implemented...
 
-	enum State
-	{
-		IntegerSign,
-		Integer,
-		Fraction,
-		ExponentSign,
-		Exponent
-	} state = IntegerSign;
-	int sign = 1;
-	unsigned long long vi = 0;
-	int fl = 0, tz = 0;
-	int exponent_sign = 1;
-	int exponent = 0;
-	bool done = false;
-
-	while (not done and not (bool)result.ec)
-	{
-		char ch = result.ptr != last ? *result.ptr : 0;
-		++result.ptr;
-
-		switch (state)
-		{
-			case IntegerSign:
-				if (ch == '-')
-				{
-					sign = -1;
-					state = Integer;
-				}
-				else if (ch == '+')
-					state = Integer;
-				else if (ch >= '0' and ch <= '9')
-				{
-					vi = ch - '0';
-					state = Integer;
-				}
-				else if (ch == '.')
-					state = Fraction;
-				else
-					result.ec = std::errc::invalid_argument;
-				break;
-
-			case Integer:
-				if (ch >= '0' and ch <= '9')
-					vi = 10 * vi + (ch - '0');
-				else if (ch == 'e' or ch == 'E')
-					state = ExponentSign;
-				else if (ch == '.')
-					state = Fraction;
-				else
-				{
-					done = true;
-					--result.ptr;
-				}
-				break;
-
-			case Fraction:
-				if (ch >= '0' and ch <= '9')
-				{
-					vi = 10 * vi + (ch - '0');
-
-					if (ch == '0')
-						tz += 1;
-					else
-					{
-						fl += tz + 1;
-						tz = 0;
-					}
-				}
-				else if (ch == 'e' or ch == 'E')
-					state = ExponentSign;
-				else
-				{
-					done = true;
-					--result.ptr;
-				}
-				break;
-
-			case ExponentSign:
-				if (ch == '-')
-				{
-					exponent_sign = -1;
-					state = Exponent;
-				}
-				else if (ch == '+')
-					state = Exponent;
-				else if (ch >= '0' and ch <= '9')
-				{
-					exponent = ch - '0';
-					state = Exponent;
-				}
-				else
-					result.ec = std::errc::invalid_argument;
-				break;
-
-			case Exponent:
-				if (ch >= '0' and ch <= '9')
-					exponent = 10 * exponent + (ch - '0');
-				else
-				{
-					done = true;
-					--result.ptr;
-				}
-				break;
-		}
-	}
-
-	if (not (bool)result.ec)
-	{
-		while (tz-- > 0)
-			vi /= 10;
-
-		long double v = std::pow(10, -fl) * vi * sign;
-		if (exponent != 0)
-			v *= std::pow(10, exponent * exponent_sign);
-
-		if (std::isnan(v))
-			result.ec = std::errc::invalid_argument;
-		else if (std::abs(v) > std::numeric_limits<FloatType>::max())
-			result.ec = std::errc::result_out_of_range;
-
-		value = static_cast<FloatType>(v);
-	}
-
-	return result;
-}
-
-/// \brief duplication of std::chars_format for deficient STL implementations
-enum class chars_format
-{
-	scientific = 1,
-	fixed = 2,
-	// hex,
-	general = fixed | scientific
-};
-
-/// \brief a simplistic implementation of std::to_chars for old STL implementations
-template <typename FloatType, std::enable_if_t<std::is_floating_point_v<FloatType>, int> = 0>
-std::to_chars_result to_chars(char *first, char *last, FloatType &value, chars_format fmt)
-{
-	int size = static_cast<int>(last - first);
-	int r = 0;
-
-	switch (fmt)
-	{
-		case chars_format::scientific:
-			if constexpr (std::is_same_v<FloatType, long double>)
-				r = snprintf(first, last - first, "%le", value);
-			else
-				r = snprintf(first, last - first, "%e", value);
-			break;
-
-		case chars_format::fixed:
-			if constexpr (std::is_same_v<FloatType, long double>)
-				r = snprintf(first, last - first, "%lf", value);
-			else
-				r = snprintf(first, last - first, "%f", value);
-			break;
-
-		case chars_format::general:
-			if constexpr (std::is_same_v<FloatType, long double>)
-				r = snprintf(first, last - first, "%lg", value);
-			else
-				r = snprintf(first, last - first, "%g", value);
-			break;
-	}
-
-	std::to_chars_result result;
-	if (r < 0 or r >= size)
-		result = { first, std::errc::value_too_large };
-	else
-		result = { first + r, std::errc() };
-
-	return result;
-}
-
-/// \brief a simplistic implementation of std::to_chars for old STL implementations
-template <typename FloatType, std::enable_if_t<std::is_floating_point_v<FloatType>, int> = 0>
-std::to_chars_result to_chars(char *first, char *last, FloatType &value, chars_format fmt, int precision)
-{
-	int size = static_cast<int>(last - first);
-	int r = 0;
-
-	switch (fmt)
-	{
-		case chars_format::scientific:
-			if constexpr (std::is_same_v<FloatType, long double>)
-				r = snprintf(first, last - first, "%.*le", precision, value);
-			else
-				r = snprintf(first, last - first, "%.*e", precision, value);
-			break;
-
-		case chars_format::fixed:
-			if constexpr (std::is_same_v<FloatType, long double>)
-				r = snprintf(first, last - first, "%.*lf", precision, value);
-			else
-				r = snprintf(first, last - first, "%.*f", precision, value);
-			break;
-
-		case chars_format::general:
-			if constexpr (std::is_same_v<FloatType, long double>)
-				r = snprintf(first, last - first, "%.*lg", precision, value);
-			else
-				r = snprintf(first, last - first, "%.*g", precision, value);
-			break;
-	}
-
-	std::to_chars_result result;
-	if (r < 0 or r >= size)
-		result = { first, std::errc::value_too_large };
-	else
-		result = { first + r, std::errc() };
-
-	return result;
-}
-
-/// \brief class that uses our implementation of std::from_chars and std::to_chars
 template <typename T>
-struct my_charconv
-{
-	/// @brief Simply call our version of std::from_chars
-	static std::from_chars_result from_chars(const char *a, const char *b, T &d)
-	{
-		return cif::from_chars(a, b, d);
-	}
+using from_chars_function = decltype(std::from_chars(std::declval<const char *>(), std::declval<const char *>(), std::declval<T &>()));
 
-	/// @brief Simply call our version of std::to_chars
-	static std::to_chars_result to_chars(char *first, char *last, T &value, chars_format fmt)
-	{
-		return cif::to_chars(first, last, value, fmt);
-	}
-};
-
-/// \brief class that uses the STL implementation of std::from_chars and std::to_chars
 template <typename T>
 struct std_charconv
 {
-	/// @brief Simply call std::from_chars
 	static std::from_chars_result from_chars(const char *a, const char *b, T &d)
 	{
 		return std::from_chars(a, b, d);
 	}
-
-	/// @brief Simply call std::to_chars
-	static std::to_chars_result to_chars(char *first, char *last, T &value, chars_format fmt)
-	{
-		return std::to_chars(first, last, value, fmt);
-	}
 };
 
-/// \brief helper to find a from_chars function
-template <typename T>
-using from_chars_function = decltype(std::from_chars(std::declval<const char *>(), std::declval<const char *>(), std::declval<T &>()));
+template <typename T, typename = void>
+struct ff_charconv;
 
-/**
- * @brief Helper to select the best implementation of charconv based on availability of the
- * function in the std:: namespace
- *
- * @tparam T The type for which we want to find a from_chars/to_chars function
- */
 template <typename T>
-using selected_charconv = typename std::conditional_t<std_experimental::is_detected_v<from_chars_function, T>, std_charconv<T>, my_charconv<T>>;
+struct ff_charconv<T, typename std::enable_if_t<std::is_floating_point_v<T>>>
+{
+	static std::from_chars_result from_chars(const char *a, const char *b, T &v);
+};
 
-} // namespace cif
+template <typename T>
+using charconv = typename std::conditional_t<std_experimental::is_detected_v<from_chars_function, T>, std_charconv<T>, ff_charconv<T>>;
+
+template <typename T>
+constexpr auto from_chars(const char *s, const char *e, T &v)
+{
+	return charconv<T>::from_chars(s, e, v);
+}
+
+/// @endcond
+
+} // namespace cif

include/cif++/utilities.hpp

@@ -28,32 +28,44 @@
 
 #include "cif++/exports.hpp"
 
+#include <cstdint>
 #include <filesystem>
 #include <iostream>
+#include <memory>
+#include <string>
+#include <string_view>
+#include <type_traits>
 
 #ifndef STDOUT_FILENO
 /// @brief For systems that lack this value
-#define STDOUT_FILENO 1
+# define STDOUT_FILENO 1
 #endif
 
 #ifndef STDERR_FILENO
 /// @brief For systems that lack this value
-#define STDERR_FILENO 2
+# define STDERR_FILENO 2
 #endif
 
 #if _WIN32
-#include <io.h>
-#define isatty _isatty
+# include <io.h>
+# define isatty _isatty
 #else
-#include <unistd.h>
+# include <unistd.h>
 #endif
 
 #if _MSC_VER
-#pragma warning(disable : 4996) // unsafe function or variable	(strcpy e.g.)
-#pragma warning(disable : 4068) // unknown pragma
-#pragma warning(disable : 4100) // unreferenced formal parameter
-#pragma warning(disable : 4101) // unreferenced local variable
-#define _SILENCE_CXX17_CODECVT_HEADER_DEPRECATION_WARNING 1
+# pragma warning(disable : 4996) // unsafe function or variable	(strcpy e.g.)
+# pragma warning(disable : 4068) // unknown pragma
+# pragma warning(disable : 4100) // unreferenced formal parameter
+# pragma warning(disable : 4101) // unreferenced local variable
+# pragma warning(disable : 4702) // unreachable code (too bad, this one. Happens in for loops)
+
+// Truncation warnings: yes, perhaps, but I think they are okay
+# pragma warning(disable : 4244)
+# pragma warning(disable : 4267)
+# pragma warning(disable : 4305)
+
+# define _SILENCE_CXX17_CODECVT_HEADER_DEPRECATION_WARNING 1
 #endif
 
 /** \file utilities.hpp
@@ -75,10 +87,10 @@ namespace cif
 extern CIFPP_EXPORT int VERBOSE;
 
 /// return the git 'build' number
-std::string get_version_nr();
+[[nodiscard]] std::string get_version_nr();
 
 /// return the width of the current output terminal, or 80 if it cannot be determined
-uint32_t get_terminal_width();
+[[nodiscard]] uint32_t get_terminal_width();
 
 // --------------------------------------------------------------------
 
@@ -87,7 +99,7 @@ namespace colour
 	/// @brief The defined colours
 	enum colour_type
 	{
-		black = 0,
+		black,
 		red,
 		green,
 		yellow,
@@ -95,7 +107,8 @@ namespace colour
 		magenta,
 		cyan,
 		white,
-		none = 9
+		_unused,
+		none
 	};
 
 	/// @brief The defined styles
@@ -126,6 +139,7 @@ namespace colour
 			{
 			}
 
+			coloured_string_t(coloured_string_t &) = delete;
 			coloured_string_t &operator=(coloured_string_t &) = delete;
 
 			/**
@@ -135,14 +149,7 @@ namespace colour
 			friend std::basic_ostream<char_type, traits_type> &operator<<(
 				std::basic_ostream<char_type, traits_type> &os, const coloured_string_t &cs)
 			{
-				bool use_colour = false;
-
-				if (os.rdbuf() == std::cout.rdbuf() and isatty(STDOUT_FILENO))
-					use_colour = true;
-				else if (os.rdbuf() == std::cerr.rdbuf() and isatty(STDERR_FILENO))
-					use_colour = true;
-
-				if (use_colour)
+				if ((os.rdbuf() == std::cout.rdbuf() and isatty(STDOUT_FILENO)) or (os.rdbuf() == std::cerr.rdbuf() and isatty(STDERR_FILENO)))
 				{
 					os << "\033[" << cs.m_fore_colour << ';' << cs.m_style << ';' << cs.m_back_colour << 'm'
 					   << cs.m_str
@@ -166,7 +173,7 @@ namespace colour
 
 /**
  * @brief Manipulator for coloured strings.
- * 
+ *
  * When writing out text to the terminal it is often useful to have
  * some of the text colourised. But only if the output is really a
  * terminal since colouring text is done using escape sequences
@@ -203,51 +210,51 @@ inline auto coloured(T str,
 
 /**
  * @brief A simple progress bar class for terminal based output
- * 
+ *
  * Using a progress bar is very convenient for the end user when
  * you have long running code. It gives feed back on how fast an
  * operation is performed and may give an indication how long it
  * will take before it is finished.
- * 
+ *
  * Using this cif::progress_bar implementation is straightforward:
- * 
+ *
  * @code {.cpp}
  * using namespace std::chrono_literals;
- * 
+ *
  * cif::progress_bar pb(10, "counting to ten");
- * 
+ *
  * for (int i = 1; i <= 10; ++i)
  * {
  *   pb.consumed(1);
  *   std::this_thread::sleep_for(1s);
  * }
- * 
+ *
  * @endcode
- * 
+ *
  * When the progress_bar is created, it first checks
  * to see if stdout is to a real TTY and if the VERBOSE
  * flag is not less than zero (quiet mode). If this passes
  * a thread is started that waits for updates.
- * 
+ *
  * The first two seconds, nothing is written to the screen
  * so if the work is finished within those two seconds
  * the screen stays clean.
- * 
+ *
  * After this time, a progress bar is printed that may look
  * like this:
- * 
+ *
  * @code
  * step 3           ========================--------------------------------  40% ⢁
  * @endcode
- * 
+ *
  * The first characters contain the initial action name or
  * the message text if it was used afterwards.
- * 
+ *
  * The thermometer is made up with '=' and '-' characters.
- * 
+ *
  * A percentage is also shown and at the end there is a spinner
  * that gives feedback that the program is really still working.
- * 
+ *
  * The progress bar is removed if the max has been reached
  * or if the progress bar is destructed. If any output has
  * been generated, the initial action is printed out along
@@ -257,13 +264,16 @@ inline auto coloured(T str,
 class progress_bar
 {
   public:
+	progress_bar(const progress_bar &) = delete;
+	progress_bar &operator=(const progress_bar &) = delete;
+
 	/**
 	 * @brief Construct a new progress bar object
-	 * 
+	 *
 	 * Progress ranges from 0 (zero) to @a inMax
-	 * 
+	 *
 	 * The action in @a inAction is used for display
-	 * 
+	 *
 	 * @param inMax The maximum value
 	 * @param inAction The description of what is
 	 * going on
@@ -273,7 +283,7 @@ class progress_bar
 
 	/**
 	 * @brief Destroy the progress bar object
-	 * 
+	 *
 	 */
 	~progress_bar();
 
@@ -295,11 +305,13 @@ class progress_bar
 	 */
 	void message(const std::string &inMessage);
 
-  private:
-	progress_bar(const progress_bar &) = delete;
-	progress_bar &operator=(const progress_bar &) = delete;
+	/**
+	 * @brief Flush the progress bar to the output stream
+	 */
+	void flush();
 
-	struct progress_bar_impl *m_impl;
+  private:
+	struct progress_bar_impl *m_impl = nullptr;
 };
 
 // --------------------------------------------------------------------
@@ -307,14 +319,14 @@ class progress_bar
 
 /**
  * @brief Load a resource from disk or the compiled in resources
- * 
+ *
  * @verbatim embed:rst
 .. note::
 
    See the :doc:`documentation on resources </resources>` for more information.
 
    @endverbatim
- * 
+ *
  * @param name The named resource to load
  * @return std::unique_ptr<std::istream> A pointer to the std::istream or empty if not found
  */
@@ -323,14 +335,14 @@ std::unique_ptr<std::istream> load_resource(std::filesystem::path name);
 
 /**
  * @brief Add a file specified by @a dataFile as the data for resource @a name
- * 
+ *
  * @verbatim embed:rst
 .. note::
 
    See the :doc:`documentation on resources </resources>` for more information.
 
    @endverbatim
- * 
+ *
  * @param name The name of the resource to specify
  * @param dataFile Path to a file containing the data
  */
@@ -339,7 +351,7 @@ void add_file_resource(const std::string &name, std::filesystem::path dataFile);
 
 /**
  * @brief List all the file resources added with cif::add_file_resource.
- * 
+ *
  * @param os The std::ostream to write the directories to
  */
 
@@ -348,7 +360,7 @@ void list_file_resources(std::ostream &os);
 /**
  * @brief Add a directory to the list of search directories. This list is
  * searched in a last-in-first-out order.
- * 
+ *
  * @verbatim embed:rst
 .. note::
 
@@ -361,7 +373,7 @@ void add_data_directory(std::filesystem::path dataDir);
 
 /**
  * @brief List all the data directories, for error reporting on missing resources.
- * 
+ *
  * @param os The std::ostream to write the directories to
  */
 

include/cif++/validate.hpp

@@ -27,15 +27,22 @@
 #pragma once
 
 #include "cif++/category.hpp"
+#include "cif++/item.hpp"
 #include "cif++/text.hpp"
 
 #include <cassert>
-#include <filesystem>
+#include <iosfwd>
 #include <list>
+#include <memory>
 #include <mutex>
 #include <optional>
+#include <set>
+#include <stdexcept>
+#include <string>
+#include <string_view>
 #include <system_error>
 #include <utility>
+#include <vector>
 
 /**
  * @file validate.hpp
@@ -65,6 +72,8 @@ enum class validation_error
 {
 	value_does_not_match_rx = 1,      /**< The value of an item does not conform to the regular expression specified for it */
 	value_is_not_in_enumeration_list, /**< The value of an item is not in the list of values allowed */
+	value_is_not_a_number,            /**< The value is not a number */
+	value_is_not_a_char_string,       /**< The value is not a character string */
 	not_a_known_primitive_type,       /**< The type is not a known primitive type */
 	undefined_category,               /**< Category has no definition in the dictionary */
 	unknown_item,                     /**< The item is not defined to be part of the category */
@@ -90,7 +99,7 @@ class validation_category_impl : public std::error_category
 	 * @return const char*
 	 */
 
-	const char *name() const noexcept override
+	[[nodiscard]] const char *name() const noexcept override
 	{
 		return "cif::validation";
 	}
@@ -102,35 +111,41 @@ class validation_category_impl : public std::error_category
 	 * @return std::string
 	 */
 
-	std::string message(int ev) const override
+	[[nodiscard]] std::string message(int ev) const override
 	{
 		switch (static_cast<validation_error>(ev))
 		{
-			case validation_error::value_does_not_match_rx:
+			using enum validation_error;
+
+			case value_does_not_match_rx:
 				return "Value in item does not match regular expression";
-			case validation_error::value_is_not_in_enumeration_list:
+			case value_is_not_in_enumeration_list:
 				return "Value is not in the enumerated list of valid values";
-			case validation_error::not_a_known_primitive_type:
+			case value_is_not_a_number:
+				return "Value is not a number";
+			case value_is_not_a_char_string:
+				return "Value is not a character string";
+			case not_a_known_primitive_type:
 				return "The type is not a known primitive type";
-			case validation_error::undefined_category:
+			case undefined_category:
 				return "Category has no definition in the dictionary";
-			case validation_error::unknown_item:
+			case unknown_item:
 				return "Item is not defined to be part of the category";
-			case validation_error::incorrect_item_validator:
+			case incorrect_item_validator:
 				return "Incorrectly specified validator for item";
-			case validation_error::missing_mandatory_items:
+			case missing_mandatory_items:
 				return "Missing mandatory items";
-			case validation_error::missing_key_items:
+			case missing_key_items:
 				return "An index could not be constructed due to missing key items";
-			case validation_error::item_not_allowed_in_category:
+			case item_not_allowed_in_category:
 				return "Requested item not allowed in category according to dictionary";
-			case validation_error::empty_file:
+			case empty_file:
 				return "The file contains no datablocks";
-			case validation_error::empty_datablock:
+			case empty_datablock:
 				return "The datablock contains no categories";
-			case validation_error::empty_category:
+			case empty_category:
 				return "The category is empty";
-			case validation_error::not_valid_pdbx:
+			case not_valid_pdbx:
 				return "The file is not a valid PDBx file";
 
 			default:
@@ -144,7 +159,7 @@ class validation_category_impl : public std::error_category
 	 *
 	 */
 
-	bool equivalent(const std::error_code & /*code*/, int /*condition*/) const noexcept override
+	[[nodiscard]] bool equivalent(const std::error_code & /*code*/, int /*condition*/) const noexcept override
 	{
 		return false;
 	}
@@ -161,21 +176,27 @@ inline std::error_category &validation_category()
 	return instance;
 }
 
+/// Return a std::error_code for a validation error
 inline std::error_code make_error_code(validation_error e)
 {
-	return std::error_code(static_cast<int>(e), validation_category());
+	return { static_cast<int>(e), validation_category() };
 }
 
+/// Return a std::error_condition for a validation error
 inline std::error_condition make_error_condition(validation_error e)
 {
-	return std::error_condition(static_cast<int>(e), validation_category());
+	return { static_cast<int>(e), validation_category() };
 }
 
 // --------------------------------------------------------------------
 
+/// Exception class for validation errors
 class validation_exception : public std::runtime_error
 {
   public:
+	// Constructors
+	/// @cond
+
 	validation_exception(validation_error err)
 		: validation_exception(make_error_code(err))
 	{
@@ -196,6 +217,7 @@ class validation_exception : public std::runtime_error
 	validation_exception(std::error_code ec, std::string_view category);
 
 	validation_exception(std::error_code ec, std::string_view category, std::string_view item);
+	/// @endcond
 };
 
 // --------------------------------------------------------------------
@@ -238,7 +260,7 @@ struct type_validator
 	type_validator(std::string_view name, DDL_PrimitiveType type, std::string_view rx);
 
 	/// @brief Copy constructor
-	type_validator(const type_validator &tv);
+	type_validator(const type_validator &tv) = default;
 
 	/// @brief Move constructor
 	type_validator(type_validator &&rhs)
@@ -254,8 +276,9 @@ struct type_validator
 	}
 
 	/// @brief Destructor
-	~type_validator();
+	~type_validator() = default;
 
+	/// Swap two type validators
 	friend void swap(type_validator &a, type_validator &b)
 	{
 		std::swap(a.m_name, b.m_name);
@@ -273,7 +296,7 @@ struct type_validator
 	/// primitive type of this type. A value of zero indicates the
 	/// values are equal. Less than zero means @a a sorts before @a b
 	/// and a value larger than zero likewise means the opposite
-	int compare(std::string_view a, std::string_view b) const;
+	[[nodiscard]] int compare(const item_value &a, const item_value &b) const;
 };
 
 /** @brief Item alias, items can be renamed over time
@@ -281,14 +304,18 @@ struct type_validator
 
 struct item_alias
 {
-	item_alias(const std::string &alias_name, const std::string &dictionary, const std::string &version)
-		: m_name(alias_name)
-		, m_dict(dictionary)
-		, m_vers(version)
+	/// constructor
+	item_alias(std::string alias_name, std::string dictionary, std::string version)
+		: m_name(std::move(alias_name))
+		, m_dict(std::move(dictionary))
+		, m_vers(std::move(version))
 	{
 	}
 
+	/// default copy constructor
 	item_alias(const item_alias &) = default;
+
+	/// default copy assignment
 	item_alias &operator=(const item_alias &) = default;
 
 	std::string m_name; ///< The alias_name
@@ -310,7 +337,7 @@ struct item_validator
 	std::string m_item_name;           ///< The item name
 	bool m_mandatory;                  ///< Flag indicating this item is mandatory
 	const type_validator *m_type;      ///< The type for this item
-	cif::iset m_enums;                 ///< If filled, the set of allowed values
+	std::set<std::string> m_enums;     ///< If filled, the set of allowed values
 	std::string m_default;             ///< If filled, a default value for this item
 	std::string m_category;            ///< The category this item_validator belongs to
 	std::vector<item_alias> m_aliases; ///< The aliases for this item
@@ -327,11 +354,13 @@ struct item_validator
 		return iequals(m_item_name, rhs.m_item_name);
 	}
 
-	/// @brief Validate the value in @a value for this item
-	/// Will throw a std::system_error exception if it fails
-	void operator()(std::string_view value) const;
+	/// @brief Validate value @a value, throws if invalid
+	void validate_value(const item_value &value) const;
 
-	/// @brief A more gentle version of value validation
+	/// @brief Validate value @a value and return potential error in @a ec
+	bool validate_value(const item_value &value, std::error_code &ec) const noexcept;
+
+	/// @brief Validate value @a value and return potential error in @a ec
 	bool validate_value(std::string_view value, std::error_code &ec) const noexcept;
 };
 
@@ -343,11 +372,11 @@ struct item_validator
  */
 struct category_validator
 {
-	std::string m_name;                         ///< The name of the category
-	std::vector<std::string> m_keys;            ///< The list of items that make up the key
-	cif::iset m_groups;                         ///< The category groups this category belongs to
-	cif::iset m_mandatory_items;                ///< The mandatory items for this category
-	std::set<item_validator> m_item_validators; ///< The item validators for the items in this category
+	std::string m_name;                            ///< The name of the category
+	std::vector<std::string> m_keys;               ///< The list of items that make up the key
+	cif::iset m_groups;                            ///< The category groups this category belongs to
+	cif::iset m_mandatory_items;                   ///< The mandatory items for this category
+	std::vector<item_validator> m_item_validators; ///< The item validators for the items in this category
 
 	/// @brief return true if this category sorts before @a rhs
 	bool operator<(const category_validator &rhs) const
@@ -359,10 +388,10 @@ struct category_validator
 	void add_item_validator(item_validator &&v);
 
 	/// @brief Return the item_validator for item @a item_name, may return nullptr
-	const item_validator *get_validator_for_item(std::string_view item_name) const;
+	[[nodiscard]] const item_validator *get_validator_for_item(std::string_view item_name) const;
 
 	/// @brief Return the item_validator for an item that has as alias name @a item_name, may return nullptr
-	const item_validator *get_validator_for_aliased_item(std::string_view item_name) const;
+	[[nodiscard]] const item_validator *get_validator_for_aliased_item(std::string_view item_name) const;
 };
 
 /**
@@ -397,8 +426,6 @@ class validator
   public:
 	/**
 	 * @brief Construct a new validator object
-	 *
-	 * @param name The name of the underlying dictionary
 	 */
 	validator()
 		: m_audit_conform("audit_conform")
@@ -408,7 +435,6 @@ class validator
 	/**
 	 * @brief Construct a new validator object
 	 *
-	 * @param name The name of the underlying dictionary
 	 * @param is The data to parse
 	 */
 	validator(std::istream &is)
@@ -420,7 +446,8 @@ class validator
 	/// @brief destructor
 	~validator() = default;
 
-	validator(const validator &rhs);
+	/// default copy constructor
+	validator(const validator &rhs) = default;
 
 	/// @brief move constructor
 	validator(validator &&rhs)
@@ -428,12 +455,14 @@ class validator
 		swap(*this, rhs);
 	}
 
+	/// default copy assignment
 	validator &operator=(validator rhs)
 	{
 		swap(*this, rhs);
 		return *this;
 	}
 
+	/// swap the two validators
 	friend void swap(validator &a, validator &b) noexcept;
 
 	friend class dictionary_parser;
@@ -447,22 +476,22 @@ class validator
 	void add_type_validator(type_validator &&v);
 
 	/// @brief Return the type validator for @a type_code, may return nullptr
-	const type_validator *get_validator_for_type(std::string_view type_code) const;
+	[[nodiscard]] const type_validator *get_validator_for_type(std::string_view type_code) const;
 
 	/// @brief Add category_validator @a v to the list of category validators
 	void add_category_validator(category_validator &&v);
 
 	/// @brief Return the category validator for @a category, may return nullptr
-	const category_validator *get_validator_for_category(std::string_view category) const;
+	[[nodiscard]] const category_validator *get_validator_for_category(std::string_view category) const;
 
 	/// @brief Add link_validator @a v to the list of link validators
 	void add_link_validator(link_validator &&v);
 
 	/// @brief Return the list of link validators for which the parent is @a category
-	std::vector<const link_validator *> get_links_for_parent(std::string_view category) const;
+	[[nodiscard]] std::vector<const link_validator *> get_links_for_parent(std::string_view category) const;
 
 	/// @brief Return the list of link validators for which the child is @a category
-	std::vector<const link_validator *> get_links_for_child(std::string_view category) const;
+	[[nodiscard]] std::vector<const link_validator *> get_links_for_child(std::string_view category) const;
 
 	/// @brief Bottleneck function to report an error in validation
 	void report_error(validation_error err, bool fatal = true) const
@@ -473,15 +502,29 @@ class validator
 	/// @brief Bottleneck function to report an error in validation
 	void report_error(std::error_code ec, bool fatal = true) const;
 
+	/// @brief Bottleneck function to report an error in validation
+	void report_error(validation_error err, std::string value, std::string_view category,
+		std::string_view item, bool fatal = true) const
+	{
+		report_error(make_error_code(err), value, category, item, fatal);
+	}
+
 	/// @brief Bottleneck function to report an error in validation
 	void report_error(validation_error err, std::string_view category,
 		std::string_view item, bool fatal = true) const
 	{
-		report_error(make_error_code(err), category, item, fatal);
+		report_error(make_error_code(err), "", category, item, fatal);
 	}
 
 	/// @brief Bottleneck function to report an error in validation
 	void report_error(std::error_code ec, std::string_view category,
+		std::string_view item, bool fatal = true) const
+	{
+		report_error(ec, "", category, item, fatal);
+	}
+
+	/// @brief Bottleneck function to report an error in validation
+	void report_error(std::error_code ec, std::string value, std::string_view category,
 		std::string_view item, bool fatal = true) const;
 
 	/// @brief Write out the audit_conform data for this validator
@@ -489,14 +532,14 @@ class validator
 	void fill_audit_conform(category &audit_conform) const;
 
 	/// @brief Return true if this validator matches @a audit_conform
-	bool matches_audit_conform(const category &audit_conform) const;
+	[[nodiscard]] bool matches_audit_conform(const category &audit_conform) const;
 
 	/// @brief Add info
 	void append_audit_conform(const std::string &name, const std::optional<std::string> &version);
 
   private:
 	// name is fully qualified here:
-	item_validator *get_validator_for_item(std::string_view name) const;
+	[[nodiscard]] item_validator *get_validator_for_item(std::string_view name) const;
 
 	category m_audit_conform;
 
@@ -520,10 +563,18 @@ class validator_factory
 	static validator_factory &instance();
 
 	/// @brief Return validator with info recorded in @a audit_conform
-	const validator &get(const category &audit_conform);
+	const validator *get(const category &audit_conform);
 
 	/// @brief Return the single-file validator with name @a dictionary_name
-	const validator &get(std::string_view dictionary_name);
+	/// and the dictionary name may be a set of dictionaries separated by comma
+	const validator *get(std::string_view dictionary_name);
+
+	/// @brief Return validator with info recorded in @a audit_conform
+	const validator &operator[](const category &audit_conform);
+
+	/// @brief Return the single-file validator with name @a dictionary_name
+	/// and the dictionary name may be a set of dictionaries separated by comma
+	const validator &operator[](std::string_view dictionary_name);
 
 	/// @brief Return true if the version @a found is equal or higher than @a expected for dictionary @a name
 	static bool check_version(std::string_view name, std::string_view expected, std::string_view found);
@@ -535,6 +586,21 @@ class validator_factory
 		return m_validators.emplace_back(std::move(v));
 	}
 
+	// #if __cplusplus >= 202302L
+	// 	/// @brief Return validator with info recorded in @a audit_conform
+	// 	static validator &operator[](const category &audit_conform)
+	// 	{
+	// 		return instance()[audit_conform];
+	// 	}
+
+	// 	/// @brief Return the single-file validator with name @a dictionary_name
+	// 	/// and the dictionary name may be a set of dictionaries separated by comma
+	// 	static validator &operator[](std::string_view dict)
+	// 	{
+	// 		return instance()[dict];
+	// 	}
+	// #endif
+
   private:
 	validator_factory() = default;
 

pcre2-simple/CMakeLists.txt

@@ -0,0 +1,316 @@
+# SPDX-License-Identifier: BSD-2-Clause
+# 
+# Copyright (c) 2025 Maarten L. Hekkelman
+# 
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+# 
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# A simplified wrapper CMakeLists.txt file for PCRE2
+#
+# This will generate an OBJECT library so it can be linked into another library
+
+cmake_minimum_required(VERSION 3.25)
+
+include(FetchContent)
+
+project(pcre2s VERSION 1.0.0 LANGUAGES C CXX)
+
+# The original code:
+
+file(DOWNLOAD https://github.com/PCRE2Project/pcre2/releases/download/pcre2-10.46/pcre2-10.46.tar.gz
+    ${CMAKE_CURRENT_BINARY_DIR}/pcre2-code.tgz
+    EXPECTED_HASH SHA256=8d28d7f2c3b970c3a4bf3776bcbb5adfc923183ce74bc8df1ebaad8c1985bd07)
+file(ARCHIVE_EXTRACT INPUT ${CMAKE_CURRENT_BINARY_DIR}/pcre2-code.tgz
+    DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
+set(PCRE2_SOURCE_DIR ${CMAKE_CURRENT_BINARY_DIR}/pcre2-10.46)
+set(PCRE2_MAJOR 10)
+set(PCRE2_MINOR 46)
+set(PCRE2_VERSION "${PCRE2_MAJOR}.${PCRE2_MINOR}")
+set(PCRE2_DATE "2024-06-09")
+
+# Some needed configuration options
+
+# option(PCRE2_BUILD_PCRE2_8 "Build 8 bit PCRE2 library" ON)
+# option(PCRE2_BUILD_PCRE2_16 "Build 16 bit PCRE2 library" OFF)
+# option(PCRE2_BUILD_PCRE2_32 "Build 32 bit PCRE2 library" OFF)
+
+option(PCRE2_STATIC_PIC "Build the static library with the option position independent code enabled." OFF)
+
+set(PCRE2_NEWLINE "LF" CACHE STRING "What to recognize as a newline (one of CR, LF, CRLF, ANY, ANYCRLF, NUL)." FORCE)
+set_property(CACHE PCRE2_NEWLINE PROPERTY STRINGS "CR" "LF" "CRLF" "ANY" "ANYCRLF" "NUL")
+
+set(PCRE2_LINK_SIZE "2" CACHE STRING "Internal link size (2, 3 or 4 allowed). See LINK_SIZE in config.h.in for details.")
+set_property(CACHE PCRE2_LINK_SIZE PROPERTY STRINGS "2" "3" "4")
+
+set(PCRE2_PARENS_NEST_LIMIT "250" CACHE STRING "Default nested parentheses limit. See PARENS_NEST_LIMIT in config.h.in for details.")
+set(PCRE2_HEAP_LIMIT "20000000" CACHE STRING "Default limit on heap memory (kibibytes). See HEAP_LIMIT in config.h.in for details.")
+set(PCRE2_MAX_VARLOOKBEHIND "255" CACHE STRING "Default limit on variable lookbehinds.")
+set(PCRE2_MATCH_LIMIT "10000000" CACHE STRING "Default limit on internal looping. See MATCH_LIMIT in config.h.in for details.")
+set(PCRE2_MATCH_LIMIT_DEPTH "MATCH_LIMIT" CACHE STRING "Default limit on internal depth of search. See MATCH_LIMIT_DEPTH in config.h.in for details.")
+set(PCRE2GREP_BUFSIZE "20480" CACHE STRING "Buffer starting size parameter for pcre2grep. See PCRE2GREP_BUFSIZE in config.h.in for details.")
+set(PCRE2GREP_MAX_BUFSIZE "1048576" CACHE STRING "Buffer maximum size parameter for pcre2grep. See PCRE2GREP_MAX_BUFSIZE in config.h.in for details.")
+set(PCRE2_SUPPORT_JIT OFF CACHE BOOL "Enable support for Just-in-time compiling.")
+
+if(${CMAKE_SYSTEM_NAME} MATCHES Linux|NetBSD)
+    set(PCRE2_SUPPORT_JIT_SEALLOC OFF CACHE BOOL "Enable SELinux compatible execmem allocator in JIT (experimental).")
+else()
+    set(PCRE2_SUPPORT_JIT_SEALLOC IGNORE)
+endif()
+
+set(PCRE2GREP_SUPPORT_JIT ON CACHE BOOL "Enable use of Just-in-time compiling in pcre2grep.")
+set(PCRE2GREP_SUPPORT_CALLOUT ON CACHE BOOL "Enable callout string support in pcre2grep.")
+set(PCRE2GREP_SUPPORT_CALLOUT_FORK ON CACHE BOOL "Enable callout string fork support in pcre2grep.")
+set(PCRE2_SUPPORT_UNICODE ON CACHE BOOL "Enable support for Unicode and UTF-8/UTF-16/UTF-32 encoding.")
+set(PCRE2_SUPPORT_BSR_ANYCRLF OFF CACHE BOOL "ON=Backslash-R matches only LF CR and CRLF, OFF=Backslash-R matches all Unicode Linebreaks")
+set(PCRE2_NEVER_BACKSLASH_C OFF CACHE BOOL "If ON, backslash-C (upper case C) is locked out.")
+set(PCRE2_SUPPORT_VALGRIND OFF CACHE BOOL "Enable Valgrind support.")
+
+if(MINGW)
+    option(NON_STANDARD_LIB_PREFIX "ON=Shared libraries built in mingw will be named pcre2.dll, etc., instead of libpcre2.dll, etc." OFF)
+    option(NON_STANDARD_LIB_SUFFIX "ON=Shared libraries built in mingw will be named libpcre2-0.dll, etc., instead of libpcre2.dll, etc." OFF)
+endif()
+
+# 
+
+set(NEWLINE_DEFAULT "")
+
+if(PCRE2_NEWLINE STREQUAL "CR")
+    set(NEWLINE_DEFAULT "1")
+elseif(PCRE2_NEWLINE STREQUAL "LF")
+    set(NEWLINE_DEFAULT "2")
+elseif(PCRE2_NEWLINE STREQUAL "CRLF")
+    set(NEWLINE_DEFAULT "3")
+elseif(PCRE2_NEWLINE STREQUAL "ANY")
+    set(NEWLINE_DEFAULT "4")
+elseif(PCRE2_NEWLINE STREQUAL "ANYCRLF")
+    set(NEWLINE_DEFAULT "5")
+elseif(PCRE2_NEWLINE STREQUAL "NUL")
+    set(NEWLINE_DEFAULT "6")
+else()
+    message(FATAL_ERROR "The PCRE2_NEWLINE variable must be set to one of the following values: \"LF\", \"CR\", \"CRLF\", \"ANY\", \"ANYCRLF\".")
+endif()
+
+# Some tests
+
+include(CheckCSourceCompiles)
+include(CheckFunctionExists)
+include(CheckSymbolExists)
+include(CheckIncludeFile)
+
+check_include_file(assert.h HAVE_ASSERT_H)
+check_include_file(dirent.h HAVE_DIRENT_H)
+check_include_file(sys/stat.h HAVE_SYS_STAT_H)
+check_include_file(sys/types.h HAVE_SYS_TYPES_H)
+check_include_file(unistd.h HAVE_UNISTD_H)
+check_include_file(windows.h HAVE_WINDOWS_H)
+
+check_symbol_exists(bcopy "strings.h" HAVE_BCOPY)
+check_symbol_exists(memfd_create "sys/mman.h" HAVE_MEMFD_CREATE)
+check_symbol_exists(memmove "string.h" HAVE_MEMMOVE)
+check_symbol_exists(secure_getenv "stdlib.h" HAVE_SECURE_GETENV)
+check_symbol_exists(strerror "string.h" HAVE_STRERROR)
+
+check_c_source_compiles(
+  "int main(void) { char buf[128] __attribute__((uninitialized)); (void)buf; return 0; }"
+  HAVE_ATTRIBUTE_UNINITIALIZED
+)
+
+check_c_source_compiles(
+  [=[
+  extern __attribute__ ((visibility ("default"))) int f(void);
+  int main(void) { return f(); }
+  int f(void) { return 42; }
+  ]=]
+  HAVE_VISIBILITY
+)
+
+if(HAVE_VISIBILITY)
+  set(PCRE2_EXPORT [=[__attribute__ ((visibility ("default")))]=])
+else()
+  set(PCRE2_EXPORT)
+endif()
+
+check_c_source_compiles("int main(void) { __assume(1); return 0; }" HAVE_BUILTIN_ASSUME)
+
+check_c_source_compiles(
+  [=[
+  #include <stddef.h>
+  int main(void) { int a,b; size_t m; __builtin_mul_overflow(a,b,&m); return 0; }
+  ]=]
+  HAVE_BUILTIN_MUL_OVERFLOW
+)
+
+check_c_source_compiles(
+  "int main(int c, char *v[]) { if (c) __builtin_unreachable(); return (int)(*v[0]); }"
+  HAVE_BUILTIN_UNREACHABLE
+)
+
+# # Check whether Intel CET is enabled, and if so, adjust compiler flags. This
+# # code was written by PH, trying to imitate the logic from the autotools
+# # configuration.
+
+# check_c_source_compiles(
+#   [=[
+#   #ifndef __CET__
+#   #error CET is not enabled
+#   #endif
+#   int main() { return 0; }
+#   ]=]
+#   INTEL_CET_ENABLED
+# )
+
+# if(INTEL_CET_ENABLED)
+#   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mshstk")
+# endif()
+
+# Set up some dependencies first
+
+configure_file(
+    ${PCRE2_SOURCE_DIR}/src/pcre2_chartables.c.dist
+    ${CMAKE_CURRENT_BINARY_DIR}/pcre2_chartables.c
+    COPYONLY
+)
+
+configure_file(
+    ${PCRE2_SOURCE_DIR}/config-cmake.h.in
+    ${CMAKE_CURRENT_BINARY_DIR}/interface/config.h
+    @ONLY
+)
+
+configure_file(
+    ${PCRE2_SOURCE_DIR}/src/pcre2.h.in
+    ${CMAKE_CURRENT_BINARY_DIR}/interface/pcre2.h
+    @ONLY
+)
+
+# Define our library
+
+list(APPEND PCRE2_HEADERS
+    ${CMAKE_CURRENT_BINARY_DIR}/interface/pcre2.h)
+
+list(APPEND PCRE2_SOURCES
+    ${PCRE2_SOURCE_DIR}/src/pcre2_auto_possess.c
+    ${CMAKE_CURRENT_BINARY_DIR}/pcre2_chartables.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_chkdint.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_compile.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_compile_class.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_config.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_context.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_convert.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_dfa_match.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_error.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_extuni.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_find_bracket.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_jit_compile.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_maketables.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_match.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_match_data.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_newline.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_ord2utf.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_pattern_info.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_script_run.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_serialize.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_string_utils.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_study.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_substitute.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_substring.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_tables.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_ucd.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_valid_utf.c
+    ${PCRE2_SOURCE_DIR}/src/pcre2_xclass.c
+)
+
+add_library(pcre2s OBJECT)
+
+target_sources(pcre2s
+    PRIVATE ${PCRE2_SOURCES}
+    PUBLIC
+    FILE_SET pcre2_headers TYPE HEADERS
+    BASE_DIRS ${PCRE2_SOURCE_DIR}/include ${CMAKE_CURRENT_BINARY_DIR}/interface
+    FILES ${PCRE2_HEADERS}
+)
+
+target_compile_definitions(pcre2s PUBLIC PCRE2_CODE_UNIT_WIDTH=8 HAVE_CONFIG_H)
+if(NOT BUILD_SHARED_LIBS)
+    target_compile_definitions(pcre2s PUBLIC PCRE2_STATIC)
+endif()
+
+target_include_directories(pcre2s PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/interface ${PCRE2_SOURCE_DIR}/src)
+
+if(PCRE2_STATIC_PIC)
+    set_target_properties(pcre2s PROPERTIES POSITION_INDEPENDENT_CODE 1)
+endif()
+
+# # Installation and config files
+
+# include(CMakePackageConfigHelpers)
+# include(GenerateExportHeader)
+
+# # Install rules
+# install(TARGETS pcre2s
+#     EXPORT pcre2s
+#     FILE_SET pcre2_headers DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+
+# if(MSVC AND BUILD_SHARED_LIBS)
+#     install(
+#         FILES $<TARGET_PDB_FILE:pcre2s>
+#         DESTINATION ${CMAKE_INSTALL_LIBDIR}
+#         OPTIONAL)
+# endif()
+
+# install(EXPORT pcre2s
+#     NAMESPACE pcre2s::
+#     FILE "pcre2s-targets.cmake"
+#     DESTINATION lib/cmake/pcre2s)
+
+# configure_package_config_file(
+#     ${CMAKE_CURRENT_SOURCE_DIR}/pcre2s-config.cmake.in ${CMAKE_CURRENT_BINARY_DIR}/pcre2s/pcre2s-config.cmake
+#     INSTALL_DESTINATION lib/cmake/pcre2s)
+
+# install(
+#     FILES "${CMAKE_CURRENT_BINARY_DIR}/pcre2s/pcre2s-config.cmake"
+#     "${CMAKE_CURRENT_BINARY_DIR}/pcre2s/pcre2s-config-version.cmake"
+#     DESTINATION lib/cmake/pcre2s)
+
+# set_target_properties(
+#     pcre2s
+#     PROPERTIES VERSION ${PCRE2_VERSION}
+#     SOVERSION ${PCRE2_VERSION}
+#     INTERFACE_pcre2s_MAJOR_VERSION ${PCRE2_MAJOR})
+
+# set_property(
+#     TARGET pcre2s
+#     APPEND
+#     PROPERTY COMPATIBLE_INTERFACE_STRING pcre2s_MAJOR_VERSION)
+
+# write_basic_package_version_file(
+#     "${CMAKE_CURRENT_BINARY_DIR}/pcre2s/pcre2s-config-version.cmake"
+#     VERSION "${PCRE2_VERSION}"
+#     COMPATIBILITY AnyNewerVersion)
+
+# # Testing
+
+# if(PROJECT_IS_TOP_LEVEL)
+#     include(CTest)
+
+#     if(BUILD_TESTING)
+#         add_subdirectory(test)
+#     endif()
+# endif()

src/compound.cpp

@@ -24,19 +24,32 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "cif++.hpp"
+#include "cif++/compound.hpp"
+#include "cif++/cif++.hpp"
 
+#include <cstddef>
+#include <exception>
 #include <filesystem>
 #include <fstream>
+#include <iomanip>
+#include <iostream>
+#include <limits>
 #include <map>
-#include <mutex>
-#include <numeric>
+#include <memory>
+#include <optional>
+#include <ranges>
 #include <shared_mutex>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <utility>
+#include <vector>
 
 namespace fs = std::filesystem;
 
 namespace cif
 {
+using std::shared_ptr;
 
 // --------------------------------------------------------------------
 
@@ -44,36 +57,32 @@ std::string to_string(bond_type bondType)
 {
 	switch (bondType)
 	{
-		case bond_type::sing: return "sing";
-		case bond_type::doub: return "doub";
-		case bond_type::trip: return "trip";
-		case bond_type::quad: return "quad";
-		case bond_type::arom: return "arom";
-		case bond_type::poly: return "poly";
-		case bond_type::delo: return "delo";
-		case bond_type::pi: return "pi";
+		using enum bond_type;
+
+		case sing: return "sing";
+		case doub: return "doub";
+		case trip: return "trip";
+		case quad: return "quad";
+		case arom: return "arom";
+		case poly: return "poly";
+		case delo: return "delo";
+		case pi: return "pi";
 	}
 	throw std::invalid_argument("Invalid bondType");
 }
 
 bond_type parse_bond_type_from_string(const std::string &bondType)
 {
-	if (cif::iequals(bondType, "sing"))
-		return bond_type::sing;
-	if (cif::iequals(bondType, "doub"))
-		return bond_type::doub;
-	if (cif::iequals(bondType, "trip"))
-		return bond_type::trip;
-	if (cif::iequals(bondType, "quad"))
-		return bond_type::quad;
-	if (cif::iequals(bondType, "arom"))
-		return bond_type::arom;
-	if (cif::iequals(bondType, "poly"))
-		return bond_type::poly;
-	if (cif::iequals(bondType, "delo"))
-		return bond_type::delo;
-	if (cif::iequals(bondType, "pi"))
-		return bond_type::pi;
+	using enum bond_type;
+
+	if (cif::iequals(bondType, "sing")) return sing;
+	if (cif::iequals(bondType, "doub")) return doub;
+	if (cif::iequals(bondType, "trip")) return trip;
+	if (cif::iequals(bondType, "quad")) return quad;
+	if (cif::iequals(bondType, "arom")) return arom;
+	if (cif::iequals(bondType, "poly")) return poly;
+	if (cif::iequals(bondType, "delo")) return delo;
+	if (cif::iequals(bondType, "pi")) return pi;
 	throw std::invalid_argument("Invalid bondType: " + bondType);
 }
 
@@ -81,21 +90,21 @@ std::string to_string(stereo_config_type stereoConfig)
 {
 	switch (stereoConfig)
 	{
-		case stereo_config_type::N: return "N";
-		case stereo_config_type::R: return "R";
-		case stereo_config_type::S: return "S";
+		using enum stereo_config_type;
+
+		case N: return "N";
+		case R: return "R";
+		case S: return "S";
 	}
 	throw std::invalid_argument("Invalid stereoConfig");
 }
 
 stereo_config_type parse_stereo_config_from_string(const std::string &stereoConfig)
 {
-	if (cif::iequals(stereoConfig, "N"))
-		return stereo_config_type::N;
-	if (cif::iequals(stereoConfig, "R"))
-		return stereo_config_type::R;
-	if (cif::iequals(stereoConfig, "S"))
-		return stereo_config_type::S;
+	using enum stereo_config_type;
+	if (cif::iequals(stereoConfig, "N")) return N;
+	if (cif::iequals(stereoConfig, "R")) return R;
+	if (cif::iequals(stereoConfig, "S")) return S;
 	throw std::invalid_argument("Invalid stereoConfig: " + stereoConfig);
 }
 
@@ -140,7 +149,7 @@ compound::compound(cif::datablock &db)
 
 	cif::tie(m_id, m_name, m_type, m_formula, m_formula_weight, m_formal_charge, one_letter_code, m_parent_id) =
 		chemComp.front().get("id", "name", "type", "formula", "formula_weight", "pdbx_formal_charge", "one_letter_code", "mon_nstd_parent_comp_id");
-	
+
 	if (one_letter_code.length() == 1)
 		m_one_letter_code = one_letter_code.front();
 
@@ -152,14 +161,21 @@ compound::compound(cif::datablock &db)
 	{
 		compound_atom atom;
 		std::string type_symbol, stereo_config;
-		cif::tie(atom.id, type_symbol, atom.charge, atom.aromatic, atom.leaving_atom, stereo_config, atom.x, atom.y, atom.z) =
+
+		std::string aromaticFlag, leavingAtomFlag;
+
+		cif::tie(atom.id, type_symbol, atom.charge, aromaticFlag, leavingAtomFlag, stereo_config, atom.x, atom.y, atom.z) =
 			row.get("atom_id", "type_symbol", "charge", "pdbx_aromatic_flag", "pdbx_leaving_atom_flag", "pdbx_stereo_config",
 				"model_Cartn_x", "model_Cartn_y", "model_Cartn_z");
+
+		atom.aromatic = iequals(aromaticFlag, "Y");
+		atom.leaving_atom = iequals(leavingAtomFlag, "Y");
+
 		atom.type_symbol = atom_type_traits(type_symbol).type();
 		if (stereo_config.empty())
 			atom.stereo_config = stereo_config_type::N;
 		else
-		atom.stereo_config = parse_stereo_config_from_string(stereo_config);
+			atom.stereo_config = parse_stereo_config_from_string(stereo_config);
 		m_atoms.push_back(std::move(atom));
 	}
 
@@ -167,12 +183,17 @@ compound::compound(cif::datablock &db)
 	for (auto row : chemCompBond)
 	{
 		compound_bond bond;
-		std::string valueOrder;
-		cif::tie(bond.atom_id[0], bond.atom_id[1], valueOrder, bond.aromatic, bond.stereo_config) = row.get("atom_id_1", "atom_id_2", "value_order", "pdbx_aromatic_flag", "pdbx_stereo_config");
+		std::string valueOrder, aromaticFlag, stereoConfigFlag;
+
+		cif::tie(bond.atom_id[0], bond.atom_id[1], valueOrder, aromaticFlag, stereoConfigFlag) = row.get("atom_id_1", "atom_id_2", "value_order", "pdbx_aromatic_flag", "pdbx_stereo_config");
+
+		bond.aromatic = iequals(aromaticFlag, "Y");
+		bond.stereo_config = iequals(stereoConfigFlag, "Y");
+
 		if (valueOrder.empty())
 			bond.type = bond_type::sing;
 		else
-		bond.type = parse_bond_type_from_string(valueOrder);
+			bond.type = parse_bond_type_from_string(valueOrder);
 		m_bonds.push_back(std::move(bond));
 	}
 }
@@ -197,7 +218,7 @@ compound_atom compound::get_atom_by_atom_id(const std::string &atom_id) const
 
 bool compound::atoms_bonded(const std::string &atomId_1, const std::string &atomId_2) const
 {
-	auto i = find_if(m_bonds.begin(), m_bonds.end(),
+	auto i = std::ranges::find_if(m_bonds,
 		[&](const compound_bond &b)
 		{
 			return (b.atom_id[0] == atomId_1 and b.atom_id[1] == atomId_2) or (b.atom_id[0] == atomId_2 and b.atom_id[1] == atomId_1);
@@ -208,7 +229,7 @@ bool compound::atoms_bonded(const std::string &atomId_1, const std::string &atom
 
 float compound::bond_length(const std::string &atomId_1, const std::string &atomId_2) const
 {
-	auto i = find_if(m_bonds.begin(), m_bonds.end(),
+	auto i = std::ranges::find_if(m_bonds,
 		[&](const compound_bond &b)
 		{
 			return (b.atom_id[0] == atomId_1 and b.atom_id[1] == atomId_2) or (b.atom_id[0] == atomId_2 and b.atom_id[1] == atomId_1);
@@ -231,18 +252,18 @@ float compound::bond_length(const std::string &atomId_1, const std::string &atom
 
 bool compound::is_peptide() const
 {
-	return iequals(m_type, "l-peptide linking")	or iequals(m_type, "peptide linking");
+	return iequals(m_type, "l-peptide linking") or iequals(m_type, "peptide linking");
 }
 
 bool compound::is_base() const
 {
-	return iequals(m_type, "dna linking")	or iequals(m_type, "rna linking");
+	return iequals(m_type, "dna linking") or iequals(m_type, "rna linking");
 }
 
 // --------------------------------------------------------------------
 // known amino acids and bases
 
-const std::map<std::string, char> compound_factory::kAAMap{
+const std::map<std::string, char> compound_factory::kAAMap{ // NOLINT(bugprone-throwing-static-initialization,cert-err58-cpp)
 	{ "ALA", 'A' },
 	{ "ARG", 'R' },
 	{ "ASN", 'N' },
@@ -267,7 +288,7 @@ const std::map<std::string, char> compound_factory::kAAMap{
 	{ "ASX", 'B' }
 };
 
-const std::map<std::string, char> compound_factory::kBaseMap{
+const std::map<std::string, char> compound_factory::kBaseMap{ // NOLINT(bugprone-throwing-static-initialization,cert-err58-cpp)
 	{ "A", 'A' },
 	{ "C", 'C' },
 	{ "G", 'G' },
@@ -285,21 +306,40 @@ const std::map<std::string, char> compound_factory::kBaseMap{
 class compound_factory_impl : public std::enable_shared_from_this<compound_factory_impl>
 {
   public:
-	compound_factory_impl();
+	compound_factory_impl() = default;
 	compound_factory_impl(const fs::path &file, std::shared_ptr<compound_factory_impl> next);
 
-	virtual ~compound_factory_impl()
+	virtual ~compound_factory_impl() // NOLINT(modernize-use-equals-default)
 	{
 		for (auto c : m_compounds)
 			delete c;
 	}
 
+	[[nodiscard]] virtual bool exists_self(const std::string &id) const
+	{
+		if (m_missing.contains(id))
+			return false;
+
+		if (std::ranges::find_if(m_compounds, [id](compound *c)
+				{ return c->id() == id; }) != m_compounds.end())
+			return true;
+
+		return m_next and m_next->exists_self(id);
+	}
+
+	bool exists(std::string_view id)
+	{
+		std::shared_lock lock(mMutex);
+
+		return exists_self(std::string{ id });
+	}
+
 	compound *get(std::string id)
 	{
 		std::shared_lock lock(mMutex);
 
 		compound *result = nullptr;
-		
+
 		for (auto impl = shared_from_this(); impl; impl = impl->m_next)
 		{
 			result = impl->create(id);
@@ -341,12 +381,8 @@ class compound_factory_impl : public std::enable_shared_from_this<compound_facto
 	std::shared_ptr<compound_factory_impl> m_next;
 };
 
-compound_factory_impl::compound_factory_impl()
-{
-}
-
 compound_factory_impl::compound_factory_impl(std::shared_ptr<compound_factory_impl> next)
-	: m_next(next)
+	: m_next(std::move(next))
 {
 }
 
@@ -363,7 +399,9 @@ compound *compound_factory_impl::create(const std::string &id)
 	if (m_missing.contains(id))
 		return nullptr;
 
-	if (auto i = find_if(m_compounds.begin(), m_compounds.end(), [id](compound *c) { return c->id() == id; }); i != m_compounds.end())
+	if (auto i = std::ranges::find_if(m_compounds, [id](compound *c)
+			{ return c->id() == id; });
+		i != m_compounds.end())
 		return *i;
 
 	compound *result = nullptr;
@@ -380,13 +418,13 @@ compound *compound_factory_impl::create(const std::string &id)
 		}
 	}
 	else
-		ccd.reset(new std::ifstream(m_file));
+		ccd = std::make_unique<std::ifstream>(m_file);
 
 	cif::file file;
 
 	if (m_index.empty())
 	{
-		if (cif::VERBOSE > 1)
+		if (VERBOSE > 1)
 		{
 			std::cout << "Creating component index "
 					  << "...";
@@ -396,7 +434,7 @@ compound *compound_factory_impl::create(const std::string &id)
 		cif::parser parser(*ccd, file);
 		m_index = parser.index_datablocks();
 
-		if (cif::VERBOSE > 1)
+		if (VERBOSE > 1)
 			std::cout << " done\n";
 
 		// reload the resource, perhaps this should be improved...
@@ -407,10 +445,10 @@ compound *compound_factory_impl::create(const std::string &id)
 				throw std::runtime_error("Could not locate the CCD components.cif file, please make sure the software is installed properly and/or use the update-libcifpp-data to fetch the data.");
 		}
 		else
-			ccd.reset(new std::ifstream(m_file));
+			ccd = std::make_unique<std::ifstream>(m_file);
 	}
 
-	if (cif::VERBOSE > 1)
+	if (VERBOSE > 1)
 	{
 		std::cout << "Loading component " << id << "...";
 		std::cout.flush();
@@ -419,7 +457,7 @@ compound *compound_factory_impl::create(const std::string &id)
 	cif::parser parser(*ccd, file);
 	parser.parse_single_datablock(id, m_index);
 
-	if (cif::VERBOSE > 1)
+	if (VERBOSE > 1)
 		std::cout << " done\n";
 
 	if (not file.empty())
@@ -445,16 +483,15 @@ compound *compound_factory_impl::create(const std::string &id)
 class local_compound_factory_impl : public compound_factory_impl
 {
   public:
-	local_compound_factory_impl(const cif::file &file, std::shared_ptr<compound_factory_impl> next)
+	local_compound_factory_impl(cif::file file, shared_ptr<compound_factory_impl> next)
 		: compound_factory_impl(next)
-		, m_local_file(file)
+		, m_local_file(std::move(file))
 	{
 	}
 
 	compound *create(const std::string &id) override;
 
   private:
-
 	compound *construct_compound(const datablock &db, const std::string &id, const std::string &name, const std::string &three_letter_code, const std::string &group);
 
 	cif::file m_local_file;
@@ -465,7 +502,9 @@ compound *local_compound_factory_impl::create(const std::string &id)
 	if (m_missing.contains(id))
 		return nullptr;
 
-	if (auto i = find_if(m_compounds.begin(), m_compounds.end(), [id](compound *c) { return c->id() == id; }); i != m_compounds.end())
+	if (auto i = std::ranges::find_if(m_compounds, [id](compound *c)
+			{ return c->id() == id; });
+		i != m_compounds.end())
 		return *i;
 
 	compound *result = nullptr;
@@ -480,10 +519,13 @@ compound *local_compound_factory_impl::create(const std::string &id)
 
 			try
 			{
-				const auto &[id, name, threeLetterCode, group] =
+				const auto &[id2, name, threeLetterCode, group] =
 					chem_comp->front().get<std::string, std::string, std::string, std::string>("id", "name", "three_letter_code", "group");
 
-				result = construct_compound(db, id, name, threeLetterCode, group);
+				if (id == id2)
+					result = construct_compound(db, id, name, threeLetterCode, group);
+				else
+					throw std::runtime_error("Compound ID's don't match: id 1=" + id + ", id 2=" + id2);
 			}
 			catch (const std::exception &ex)
 			{
@@ -507,12 +549,10 @@ compound *local_compound_factory_impl::construct_compound(const datablock &rdb,
 
 	float formula_weight = 0;
 	int formal_charge = 0;
-	std::map<std::string,std::size_t> formula_data;
+	std::map<std::string, std::size_t> formula_data;
 
 	for (std::size_t ord = 1; const auto &[atom_id, type_symbol, type, charge, x, y, z, xi, yi, zi] :
-		rdb["chem_comp_atom"].rows<std::string, std::string, std::string, int,
-			std::optional<float>, std::optional<float>, std::optional<float>,
-			std::optional<float>, std::optional<float>, std::optional<float>>(
+		rdb["chem_comp_atom"].rows<std::string, std::string, std::string, int, std::optional<float>, std::optional<float>, std::optional<float>, std::optional<float>, std::optional<float>, std::optional<float>>(
 			"atom_id", "type_symbol", "type", "charge",
 			"model_Cartn_x", "model_Cartn_y", "model_Cartn_z",
 			"pdbx_model_Cartn_x_ideal", "pdbx_model_Cartn_y_ideal", "pdbx_model_Cartn_z_ideal"))
@@ -522,22 +562,20 @@ compound *local_compound_factory_impl::construct_compound(const datablock &rdb,
 
 		formula_data[type_symbol] += 1;
 
-		db["chem_comp_atom"].emplace({
-			{ "comp_id", id },
+		db["chem_comp_atom"].emplace({ { "comp_id", id },
 			{ "atom_id", atom_id },
 			{ "type_symbol", type_symbol },
 			{ "charge", charge },
-			{ "model_Cartn_x",  x.has_value() ? x : xi, 3 },
-			{ "model_Cartn_y",  y.has_value() ? y : yi, 3 },
-			{ "model_Cartn_z",  z.has_value() ? z : zi, 3 },
-			{ "pdbx_ordinal", ord++ }
-		});
+			{ "model_Cartn_x", { x.has_value() ? x : xi , 3 } },
+			{ "model_Cartn_y", { y.has_value() ? y : yi , 3 } },
+			{ "model_Cartn_z", { z.has_value() ? z : zi , 3 } },
+			{ "pdbx_ordinal", ord++ } });
 
 		formal_charge += charge;
 	}
 
 	for (std::size_t ord = 1; const auto &[atom_id_1, atom_id_2, type, aromatic] :
-		rdb["chem_comp_bond"].rows<std::string, std::string, std::string, bool>("atom_id_1", "atom_id_2", "type", "aromatic"))
+		rdb["chem_comp_bond"].rows<std::string, std::string, std::string, std::string>("atom_id_1", "atom_id_2", "type", "aromatic"))
 	{
 		std::string value_order("SING");
 
@@ -548,21 +586,19 @@ compound *local_compound_factory_impl::construct_compound(const datablock &rdb,
 		else if (cif::iequals(type, "triple") or cif::iequals(type, "trip"))
 			value_order = "TRIP";
 
-		db["chem_comp_bond"].emplace({
-			{ "comp_id", id },
+		db["chem_comp_bond"].emplace({ { "comp_id", id },
 			{ "atom_id_1", atom_id_1 },
 			{ "atom_id_2", atom_id_2 },
 			{ "value_order", value_order },
 			{ "pdbx_aromatic_flag", aromatic },
 			// TODO: fetch stereo_config info from chem_comp_chir
-			{ "pdbx_ordinal", ord++ }
-		});
+			{ "pdbx_ordinal", ord++ } });
 	}
 
 	db.emplace_back(rdb["pdbx_chem_comp_descriptor"]);
 
 	std::string formula;
-	for (bool first = true; const auto &[symbol, count]: formula_data)
+	for (bool first = true; const auto &[symbol, count] : formula_data)
 	{
 		if (std::exchange(first, false))
 			formula += ' ';
@@ -581,15 +617,13 @@ compound *local_compound_factory_impl::construct_compound(const datablock &rdb,
 	else
 		type = "NON-POLYMER";
 
-	db["chem_comp"].emplace({
-		{ "id", id },
+	db["chem_comp"].emplace({ { "id", id },
 		{ "name", name },
 		{ "type", type },
 		{ "formula", formula },
 		{ "pdbx_formal_charge", formal_charge },
-		{ "formula_weight", formula_weight },
-		{ "three_letter_code", three_letter_code }
-	});
+		{ "formula_weight", { formula_weight, 3 } },
+		{ "three_letter_code", three_letter_code } });
 
 	std::shared_lock lock(mMutex);
 
@@ -615,14 +649,10 @@ compound_factory::compound_factory()
 	auto ccd = cif::load_resource("components.cif");
 	if (ccd)
 		m_impl = std::make_shared<compound_factory_impl>();
-	else if (cif::VERBOSE > 0)
+	else if (VERBOSE > 0)
 		std::cerr << "CCD components.cif resource was not found\n";
 }
 
-compound_factory::~compound_factory()
-{
-}
-
 compound_factory &compound_factory::instance()
 {
 	if (s_use_thread_local_instance)
@@ -654,7 +684,7 @@ void compound_factory::set_default_dictionary(const fs::path &inDictFile)
 
 	try
 	{
-		m_impl.reset(new compound_factory_impl(inDictFile, m_impl));
+		m_impl = std::make_shared<compound_factory_impl>(inDictFile, m_impl);
 	}
 	catch (const std::exception &)
 	{
@@ -669,7 +699,7 @@ void compound_factory::push_dictionary(const fs::path &inDictFile)
 
 	try
 	{
-		m_impl.reset(new compound_factory_impl(inDictFile, m_impl));
+		m_impl = std::make_shared<compound_factory_impl>(inDictFile, m_impl);
 	}
 	catch (const std::exception &)
 	{
@@ -681,7 +711,7 @@ void compound_factory::push_dictionary(const cif::file &inDictFile)
 {
 	try
 	{
-		m_impl.reset(new local_compound_factory_impl(inDictFile, m_impl));
+		m_impl = std::make_shared<local_compound_factory_impl>(inDictFile, m_impl);
 	}
 	catch (const std::exception &)
 	{
@@ -695,6 +725,11 @@ void compound_factory::pop_dictionary()
 		m_impl = m_impl->next();
 }
 
+bool compound_factory::exists(std::string_view id) const
+{
+	return m_impl and m_impl->exists(id);
+}
+
 const compound *compound_factory::create(std::string_view id)
 {
 	auto result = m_impl ? m_impl->get(std::string{ id }) : nullptr;
@@ -719,7 +754,7 @@ bool compound_factory::is_peptide(std::string_view res_name) const
 	bool result = is_std_peptide(res_name);
 	if (not result and m_impl)
 	{
-		auto compound = const_cast<compound_factory&>(*this).create(res_name);
+		auto compound = const_cast<compound_factory &>(*this).create(res_name);
 		result = compound != nullptr and compound->is_peptide();
 	}
 	return result;
@@ -731,7 +766,7 @@ bool compound_factory::is_base(std::string_view res_name) const
 	bool result = is_std_base(res_name);
 	if (not result and m_impl)
 	{
-		auto compound = const_cast<compound_factory&>(*this).create(res_name);
+		auto compound = const_cast<compound_factory &>(*this).create(res_name);
 		result = compound != nullptr and compound->is_base();
 	}
 	return result;
@@ -764,8 +799,8 @@ void compound_factory::report_missing_compound(std::string_view compound_id)
 		std::clog << "\n"
 				  << cif::coloured("Configuration error:", white, red) << "\n\n"
 				  << "The attempt to retrieve compound information for " << std::quoted(compound_id) << " failed.\n\n"
-				  << "This information is searched for in a CCD file called components.cif or\n"
-				  << "components.cif.gz which should be located in one of the following directories:\n\n";
+				  << "This information is searched for in a CCD file called components.cif\n"
+				  << "which should be located in one of the following directories:\n\n";
 
 		cif::list_data_directories(std::clog);
 
@@ -781,7 +816,7 @@ void compound_factory::report_missing_compound(std::string_view compound_id)
 				  << "in /var/cache/libcifpp using the following commands:\n\n"
 				  << "curl -o " << CACHE_DIR << "/components.cif https://files.wwpdb.org/pub/pdb/data/monomers/components.cif\n"
 				  << "curl -o " << CACHE_DIR << "/mmcif_pdbx.dic https://mmcif.wwpdb.org/dictionaries/ascii/mmcif_pdbx_v50.dic\n"
-				  << "curl -o " << CACHE_DIR << "/mmcif_ma.dic https://github.com/ihmwg/ModelCIF/raw/master/dist/mmcif_ma.dic\n\n";
+				  << "curl -o " << CACHE_DIR << "/mmcif_ma.dic https://mmcif.wwpdb.org/dictionaries/ascii/mmcif_ma.dic\n\n";
 #endif
 
 		if (m_impl)

src/condition.cpp

@@ -24,9 +24,17 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "cif++/condition.hpp"
-#include "cif++/category.hpp"
-#include "cif++/validate.hpp"
+#include "cif++/cif++.hpp"
+
+#include <algorithm>
+#include <cstddef>
+#include <cstdint>
+#include <optional>
+#include <set>
+#include <string>
+#include <string_view>
+#include <typeinfo>
+#include <vector>
 
 namespace cif
 {
@@ -36,9 +44,13 @@ iset get_category_items(const category &cat)
 	return cat.key_items();
 }
 
-uint16_t get_item_ix(const category &cat, std::string_view col)
+std::optional<uint16_t> get_item_ix(const category &cat, std::string_view col)
 {
-	return cat.get_item_ix(col);
+	auto ix = cat.get_item_ix(col);
+	std::optional<uint16_t> result;
+	if (ix < cat.get_item_count())
+		result = ix;
+	return result;
 }
 
 bool is_item_type_uchar(const category &cat, std::string_view col)
@@ -75,7 +87,7 @@ namespace detail
 	// 			return this;
 	// 		}
 	//
-	// 		bool test(row_handle r) const override
+	// 		bool test(const_row_handle r) const override
 	// 		{
 	// 			return m_single_hit == r;
 	// 		}
@@ -110,32 +122,24 @@ namespace detail
 
 	condition_impl *key_equals_condition_impl::prepare(const category &c)
 	{
-		m_item_ix = c.get_item_ix(m_item_name);
-		m_icase = is_item_type_uchar(c, m_item_name);
+		condition_impl *result = nullptr;
 
-		if (c.get_cat_validator() != nullptr and
-			c.key_item_indices().contains(m_item_ix) and
-			c.key_item_indices().size() == 1)
+		if (auto ix = get_item_ix(c, m_item_name); ix.has_value())
 		{
-			m_single_hit = c[{ { m_item_name, m_value } }];
+			m_item_ix = *ix;
+			m_icase = is_item_type_uchar(c, m_item_name);
+
+			if (auto cv = c.get_cat_validator();
+				cv != nullptr and cv->m_keys.size() == 1 and
+				cv->m_keys.front() == m_item_name)
+			{
+				m_single_hit = c[{ { m_item_name, m_value } }];
+			}
+
+			result = this;
 		}
 
-		return this;
-	}
-
-	condition_impl *key_equals_number_condition_impl::prepare(const category &c)
-	{
-		m_item_ix = c.get_item_ix(m_item_name);
-
-		if (c.get_cat_validator() != nullptr and
-			c.key_item_indices().contains(m_item_ix) and
-			c.key_item_indices().size() == 1)
-		{
-			item v(m_item_name, m_value);
-			m_single_hit = c[{ { m_item_name, std::string{ v.value() }, false } }];
-		}
-
-		return this;
+		return result;
 	}
 
 	bool found_in_range(condition_impl *c, std::vector<and_condition_impl *>::iterator b, std::vector<and_condition_impl *>::iterator e)
@@ -146,7 +150,7 @@ namespace detail
 		{
 			auto &cs = (*s)->m_sub;
 
-			if (find_if(cs.begin(), cs.end(), [c](const condition_impl *i)
+			if (std::ranges::find_if(cs, [c](const condition_impl *i)
 					{ return i->equals(c); }) == cs.end())
 			{
 				result = false;
@@ -177,7 +181,7 @@ namespace detail
 				and_result = new and_condition_impl();
 
 			and_result->m_sub.push_back(c);
-			fc.erase(fc.begin() + fc_i);
+			fc.erase(fc.begin() + static_cast<std::string::difference_type>(fc_i));
 
 			for (auto sub : subs)
 			{
@@ -192,7 +196,7 @@ namespace detail
 						continue;
 					}
 
-					ssub.erase(ssub.begin() + ssub_i);
+					ssub.erase(ssub.begin() + static_cast<std::string::difference_type>(ssub_i));
 					delete sc;
 					break;
 				}
@@ -211,7 +215,10 @@ namespace detail
 	condition_impl *and_condition_impl::prepare(const category &c)
 	{
 		for (auto &sub : m_sub)
-			sub = sub->prepare(c);
+		{
+			if (sub->prepare(c) == nullptr)
+				return nullptr;
+		}
 
 		if (auto cv = c.get_cat_validator(); cv != nullptr)
 		{
@@ -234,17 +241,6 @@ namespace detail
 					continue;
 				}
 
-				if (auto s = dynamic_cast<const key_equals_number_condition_impl *>(sub); s != nullptr)
-				{
-					if (keys.contains(s->m_item_name))
-					{
-						item v{ s->m_item_name, s->m_value };
-						lookup.emplace_back(s->m_item_name, std::string{ v.value() } );
-						subs.emplace_back(sub);
-					}
-					continue;
-				}
-
 				if (auto s = dynamic_cast<const key_equals_or_empty_condition_impl *>(sub); s != nullptr)
 				{
 					if (keys.contains(s->m_item_name))
@@ -255,17 +251,6 @@ namespace detail
 					}
 					continue;
 				}
-
-				if (auto s = dynamic_cast<const key_equals_number_or_empty_condition_impl *>(sub); s != nullptr)
-				{
-					if (keys.contains(s->m_item_name))
-					{
-						item v{ s->m_item_name, s->m_value };
-						lookup.emplace_back(s->m_item_name, std::string{ v.value() }, true );
-						subs.emplace_back(sub);
-					}
-					continue;
-				}
 			}
 
 			if (lookup.size() == keys.size())
@@ -273,14 +258,14 @@ namespace detail
 				m_single = c[lookup];
 
 				for (auto s : subs)
-					m_sub.erase(std::remove(m_sub.begin(), m_sub.end(), s), m_sub.end());
+					std::erase(m_sub, s);
 			}
 		}
 
 		return this;
 	}
 
-	bool and_condition_impl::test(row_handle r) const
+	bool and_condition_impl::test(const_row_handle r) const
 	{
 		bool result = true;
 
@@ -307,25 +292,30 @@ namespace detail
 
 		for (auto &sub : m_sub)
 		{
-			sub = sub->prepare(c);
+			if (sub->prepare(c) == nullptr)
+			{
+				delete sub;
+				sub = nullptr;
+				continue;
+			}
+
 			if (typeid(*sub) == typeid(and_condition_impl))
 				and_conditions.push_back(static_cast<and_condition_impl *>(sub));
 		}
 
-		if (and_conditions.size() == m_sub.size())
+		std::erase(m_sub, nullptr);
+
+		if (not m_sub.empty() and and_conditions.size() == m_sub.size())
 			return and_condition_impl::combine_equal(and_conditions, this);
 
-		return this;
+		return m_sub.empty() ? nullptr : this;
 	}
 
 } // namespace detail
 
-void condition::prepare(const category &c)
+bool condition::prepare(const category &c)
 {
-	if (m_impl)
-		m_impl = m_impl->prepare(c);
-
-	m_prepared = true;
+	return m_impl and m_impl->prepare(c) != nullptr;
 }
 
 } // namespace cif

src/datablock.cpp

@@ -24,8 +24,19 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "cif++/datablock.hpp"
-#include "cif++/validate.hpp"
+#include "cif++/cif++.hpp"
+
+#include <algorithm>
+#include <cassert>
+#include <exception>
+#include <iostream>
+#include <list>
+#include <ranges>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <tuple>
+#include <vector>
 
 namespace cif
 {
@@ -42,7 +53,28 @@ datablock::datablock(const datablock &db)
 void datablock::load_dictionary()
 {
 	if (auto *audit_conform = get("audit_conform"); audit_conform and not audit_conform->empty())
-		set_validator(&validator_factory::instance().get(*audit_conform));
+	{
+		try
+		{
+			set_validator(validator_factory::instance().get(*audit_conform));
+		}
+		catch (const std::exception &ex)
+		{
+			std::clog << ex.what() << '\n';
+		}
+	}
+}
+
+void datablock::load_dictionary(std::string_view dict)
+{
+	try
+	{
+		set_validator(validator_factory::instance().get(dict));
+	}
+	catch (const std::exception &ex)
+	{
+		std::clog << ex.what() << '\n';
+	}
 }
 
 void datablock::set_validator(const validator *v)
@@ -96,16 +128,16 @@ bool datablock::strip()
 	bool result = true;
 
 	// remove all categories that have no validator
-	erase(std::remove_if(begin(), end(), [](category &c) {
+	std::erase_if(*this, [](category &c)
+		{
 		bool result = false;
 		if (c.get_cat_validator() == nullptr)
 		{
-			if (cif::VERBOSE > 0)
+			if (VERBOSE > 0)
 				std::clog << "Dropping category " << c.name() << '\n';
 			result = true;
 		}
-		return result;
-	}), end());
+		return result; });
 
 	// then strip the remaining categories
 	for (auto &cat : *this)
@@ -134,7 +166,7 @@ bool datablock::strip()
 
 category &datablock::operator[](std::string_view name)
 {
-	auto i = std::find_if(begin(), end(), [name](const category &c)
+	auto i = std::ranges::find_if(*this, [name](const category &c)
 		{ return iequals(c.name(), name); });
 
 	if (i != end())
@@ -151,14 +183,14 @@ category &datablock::operator[](std::string_view name)
 const category &datablock::operator[](std::string_view name) const
 {
 	static const category s_empty;
-	auto i = std::find_if(begin(), end(), [name](const category &c)
+	auto i = std::ranges::find_if(*this, [name](const category &c)
 		{ return iequals(c.name(), name); });
 	return i == end() ? s_empty : *i;
 }
 
 category *datablock::get(std::string_view name)
 {
-	auto i = std::find_if(begin(), end(), [name](const category &c)
+	auto i = std::ranges::find_if(*this, [name](const category &c)
 		{ return iequals(c.name(), name); });
 	return i == end() ? nullptr : &*i;
 }
@@ -204,7 +236,7 @@ std::vector<std::string> datablock::get_item_order() const
 	std::vector<std::string> result;
 
 	// for entry and audit_conform on top
-	auto ci = find_if(begin(), end(), [](const category &cat)
+	auto ci = std::ranges::find_if(*this, [](const category &cat)
 		{ return cat.name() == "entry"; });
 	if (ci != end())
 	{
@@ -212,7 +244,7 @@ std::vector<std::string> datablock::get_item_order() const
 		result.insert(result.end(), cto.begin(), cto.end());
 	}
 
-	ci = find_if(begin(), end(), [](const category &cat)
+	ci = std::ranges::find_if(*this, [](const category &cat)
 		{ return cat.name() == "audit_conform"; });
 	if (ci != end())
 	{
@@ -260,7 +292,7 @@ namespace
 
 		for (auto link : validator.get_links_for_child(cat))
 		{
-			auto ei = std::find_if(cat_order.begin(), cat_order.end(), [parent = link->m_parent_category](elem_t &a)
+			auto ei = std::ranges::find_if(cat_order, [parent = link->m_parent_category](elem_t &a)
 				{ return std::get<0>(a) == parent; });
 
 			if (ei == cat_order.end())
@@ -297,7 +329,7 @@ void datablock::write(std::ostream &os) const
 		for (auto i = cat_order.begin(); i != cat_order.end(); ++i)
 			calculate_cat_order(cat_order, i, *m_validator);
 
-		std::sort(cat_order.begin(), cat_order.end(), [](const elem_t &a, const elem_t &b)
+		std::ranges::sort(cat_order, [](const elem_t &a, const elem_t &b)
 			{
 			const auto &[cat_a, count_a, on_stack_a] = a;
 			const auto &[cat_b, count_b, on_stack_b] = b;
@@ -349,7 +381,7 @@ void datablock::write(std::ostream &os, const std::vector<std::string> &item_nam
 	{
 		std::string cat_name, item_name;
 		std::tie(cat_name, item_name) = split_item_name(o);
-		if (find_if(cat_order.rbegin(), cat_order.rend(), [cat_name](const std::string &s) -> bool
+		if (std::ranges::find_if(std::ranges::reverse_view(cat_order), [cat_name](const std::string &s) -> bool
 				{ return iequals(cat_name, s); }) == cat_order.rend())
 			cat_order.push_back(cat_name);
 	}
@@ -376,7 +408,7 @@ void datablock::write(std::ostream &os, const std::vector<std::string> &item_nam
 	// for any Category we missed in the catOrder
 	for (auto &cat : *this)
 	{
-		if (find_if(cat_order.begin(), cat_order.end(), [&](const std::string &s) -> bool
+		if (std::ranges::find_if(cat_order, [&](const std::string &s) -> bool
 				{ return iequals(cat.name(), s); }) != cat_order.end())
 			continue;
 
@@ -400,14 +432,14 @@ bool datablock::operator==(const datablock &rhs) const
 		if (not cat.empty())
 			catA.push_back(cat.name());
 	}
-	std::sort(catA.begin(), catA.end());
+	std::ranges::sort(catA);
 
 	for (auto &cat : dbB)
 	{
 		if (not cat.empty())
 			catB.push_back(cat.name());
 	}
-	std::sort(catB.begin(), catB.end());
+	std::ranges::sort(catB);
 
 	// loop over categories twice, to group output
 	// First iteration is to list missing categories.

src/dictionary_parser.cpp

@@ -24,10 +24,25 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "cif++/condition.hpp"
-#include "cif++/dictionary_parser.hpp"
-#include "cif++/file.hpp"
-#include "cif++/parser.hpp"
+#include "cif++/cif++.hpp"
+#include "cif++/text.hpp"
+#include "cif++/validate.hpp"
+
+#include <cstddef>
+#include <exception>
+#include <format>
+#include <iostream>
+#include <map>
+#include <memory>
+#include <optional>
+#include <ranges>
+#include <set>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <tuple>
+#include <utility>
+#include <vector>
 
 namespace cif
 {
@@ -46,7 +61,7 @@ class dictionary_parser : public parser
 	void load_dictionary()
 	{
 		std::unique_ptr<datablock> dict;
-		auto savedDatablock = m_datablock;
+		auto savedDatablock = std::exchange(m_datablock, nullptr);
 
 		try
 		{
@@ -60,7 +75,7 @@ class dictionary_parser : public parser
 
 					default:
 					{
-						dict.reset(new datablock(m_token_value)); // dummy datablock, for constructing the validator only
+						dict = std::make_unique<datablock>(m_token_value); // dummy datablock, for constructing the validator only
 						m_datablock = dict.get();
 
 						match(CIFToken::DATA);
@@ -75,6 +90,9 @@ class dictionary_parser : public parser
 			error(ex.what());
 		}
 
+		if (m_datablock == nullptr)
+			throw std::runtime_error("Dictionary file is empty?");
+
 		// store all validators
 		for (auto &ic : mCategoryValidators)
 			m_validator.add_category_validator(std::move(ic));
@@ -87,7 +105,19 @@ class dictionary_parser : public parser
 				error("Undefined category '" + iv.first);
 
 			for (auto &v : iv.second)
+			{
+				// enums, make lower case if needed
+				auto tv = v.m_type;
+				if (tv and tv->m_primitive_type == DDL_PrimitiveType::UChar)
+				{
+					std::set<std::string> es;
+					for (auto &e : v.m_enums)
+						es.emplace(cif::to_lower_copy(e));
+					std::swap(es, v.m_enums);
+				}
+
 				const_cast<category_validator *>(cv)->add_item_validator(std::move(v));
+			}
 		}
 
 		// check all item validators for having a typeValidator
@@ -98,7 +128,7 @@ class dictionary_parser : public parser
 		// store meta information
 		if (auto dictionary = m_datablock->get("dictionary"); dictionary != nullptr and not dictionary->empty())
 		{
-			const auto &[name, version] = dictionary->front().get<std::string,std::optional<std::string>>("title", "version");
+			const auto &[name, version] = dictionary->front().get<std::string, std::optional<std::string>>("title", "version");
 			m_validator.append_audit_conform(name, version);
 		}
 
@@ -113,7 +143,7 @@ class dictionary_parser : public parser
 		if (not m_collected_item_types)
 			m_collected_item_types = collect_item_types();
 
-		std::string saveFrameName { m_token_value };
+		std::string saveFrameName{ m_token_value };
 
 		if (saveFrameName.empty())
 			error("Invalid save frame, should contain more than just 'save_' here");
@@ -121,7 +151,7 @@ class dictionary_parser : public parser
 		bool isCategorySaveFrame = m_token_value[0] != '_';
 
 		datablock dict(m_token_value);
-		datablock::iterator cat = dict.end();
+		auto cat = dict.end();
 
 		match(CIFToken::SAVE_NAME);
 		while (m_lookahead == CIFToken::LOOP or m_lookahead == CIFToken::ITEM_NAME)
@@ -147,15 +177,41 @@ class dictionary_parser : public parser
 					match(CIFToken::ITEM_NAME);
 				}
 
-				while (m_lookahead == CIFToken::VALUE)
+				while (m_lookahead >= CIFToken::VALUE_INAPPLICABLE)
 				{
 					cat->emplace({});
 					auto row = cat->back();
 
 					for (auto item_name : item_names)
 					{
-						row[item_name] = m_token_value;
-						match(CIFToken::VALUE);
+						switch (m_lookahead)
+						{
+							using enum CIFToken;
+
+							case VALUE_INAPPLICABLE:
+								row[item_name] = nullptr;
+								match(VALUE_INAPPLICABLE);
+								break;
+							case VALUE_UNKNOWN:
+								row[item_name] = item_value{ std::optional<std::string>{} };
+								match(VALUE_UNKNOWN);
+								break;
+							case VALUE_NUMERIC_INTEGER:
+								row[item_name] = m_token_value_int;
+								match(VALUE_NUMERIC_INTEGER);
+								break;
+							case VALUE_NUMERIC_FLOAT:
+								row[item_name] = m_token_value_float;
+								match(VALUE_NUMERIC_FLOAT);
+								break;
+							case VALUE_CHARSTRING:
+							case VALUE_TEXTFIELD:
+								row[item_name] = m_token_value;
+								match(m_lookahead);
+								break;
+							default:
+								match(VALUE_CHARSTRING);
+						}
 					}
 				}
 
@@ -173,9 +229,35 @@ class dictionary_parser : public parser
 
 				if (cat->empty())
 					cat->emplace({});
-				cat->back()[item_name] = m_token_value;
 
-				match(CIFToken::VALUE);
+				switch (m_lookahead)
+				{
+					using enum CIFToken;
+
+					case VALUE_INAPPLICABLE:
+						cat->back()[item_name] = nullptr;
+						match(VALUE_INAPPLICABLE);
+						break;
+					case VALUE_UNKNOWN:
+						cat->back()[item_name] = item_value{ std::optional<std::string>{} };
+						match(VALUE_UNKNOWN);
+						break;
+					case VALUE_NUMERIC_INTEGER:
+						cat->back()[item_name] = m_token_value_int;
+						match(VALUE_NUMERIC_INTEGER);
+						break;
+					case VALUE_NUMERIC_FLOAT:
+						cat->back()[item_name] = m_token_value_float;
+						match(VALUE_NUMERIC_FLOAT);
+						break;
+					case VALUE_CHARSTRING:
+					case VALUE_TEXTFIELD:
+						cat->back()[item_name] = m_token_value;
+						match(m_lookahead);
+						break;
+					default:
+						match(VALUE_CHARSTRING);
+				}
 			}
 		}
 
@@ -183,32 +265,39 @@ class dictionary_parser : public parser
 
 		if (isCategorySaveFrame)
 		{
-			std::string category = dict["category"].front().get<std::string>("id");
+			auto category = dict["category"].front().get<std::string>("id");
 
 			std::vector<std::string> keys;
 			for (auto k : dict["category_key"])
-				keys.push_back(std::get<1>(split_item_name(k["name"].as<std::string>())));
+				keys.push_back(std::get<1>(split_item_name(k["name"].get<std::string>())));
 
 			iset groups;
 			for (auto g : dict["category_group"])
-				groups.insert(g["id"].as<std::string>());
+				groups.insert(g["id"].get<std::string>());
 
 			mCategoryValidators.push_back(category_validator{ category, keys, groups });
 		}
 		else
 		{
 			// if the type code is missing, this must be a pointer, just skip it
-			std::string typeCode = dict["item_type"].front().get<std::string>("code");
+			std::optional<std::string> typeCode;
+
+			if (not dict["item_type"].empty())
+				typeCode = dict["item_type"].front().get<std::optional<std::string>>("code");
 
 			const type_validator *tv = nullptr;
-			if (not(typeCode.empty() or typeCode == "?"))
-				tv = m_validator.get_validator_for_type(typeCode);
+			if (typeCode.has_value())
+				tv = m_validator.get_validator_for_type(*typeCode);
 
-			iset ess;
+			std::set<std::string> ess;
 			for (auto e : dict["item_enumeration"])
-				ess.insert(e["value"].as<std::string>());
+				ess.insert(e["value"].get<std::string>());
+			for (auto e : dict["pdbx_item_enumeration"])
+				ess.insert(e["value"].get<std::string>());
 
-			std::string defaultValue = dict["item_default"].front().get<std::string>("value");
+			std::string defaultValue;
+			if (auto &cat = dict["item_default"]; not cat.empty())
+				defaultValue = cat.front().get<std::string>("value");
 			// bool defaultIsNull = false;
 			// if (defaultValue.empty())
 			// {
@@ -222,7 +311,7 @@ class dictionary_parser : public parser
 
 			std::vector<item_alias> aliases;
 			for (const auto &[alias_name, dictionary, version] :
-				dict["item_aliases"].rows<std::string,std::string,std::string>("alias_name", "dictionary", "version"))
+				dict["item_aliases"].rows<std::string, std::string, std::string>("alias_name", "dictionary", "version"))
 			{
 				aliases.emplace_back(alias_name, dictionary, version);
 			}
@@ -230,8 +319,7 @@ class dictionary_parser : public parser
 			// collect the dict from our dataBlock and construct validators
 			for (auto i : dict["item"])
 			{
-				std::string item, category, mandatory;
-				cif::tie(item, category, mandatory) = i.get("name", "category_id", "mandatory_code");
+				auto &&[item, category, mandatory] = i.get<std::string, std::string, std::string>("name", "category_id", "mandatory_code");
 
 				std::string cat_name, item_name;
 				std::tie(cat_name, item_name) = split_item_name(item);
@@ -246,9 +334,9 @@ class dictionary_parser : public parser
 
 				auto &ivs = mItemValidators[category];
 
-				auto vi = find(ivs.begin(), ivs.end(), item_validator{ item_name });
+				auto vi = std::ranges::find(ivs, item_validator{ item_name });
 				if (vi == ivs.end())
-					ivs.push_back(item_validator{ item_name, iequals(mandatory, "yes"), tv, ess, defaultValue, cat_name, std::move(aliases) });
+					ivs.push_back(item_validator{ item_name, iequals(mandatory, "yes"), tv, ess, defaultValue, cat_name, aliases });
 				else
 				{
 					// need to update the itemValidator?
@@ -287,9 +375,7 @@ class dictionary_parser : public parser
 
 			// collect the dict from our dataBlock and construct validators
 			for (auto i : dict["item_linked"])
-			{
-				mLinkedItems.emplace(i.get<std::string,std::string>("child_name", "parent_name"));
-			}
+				mLinkedItems.emplace(i.get<std::string, std::string>("child_name", "parent_name"));
 		}
 	}
 
@@ -334,9 +420,7 @@ class dictionary_parser : public parser
 
 		for (auto gl : linkedGroupList)
 		{
-			std::string child, parent;
-			int link_group_id;
-			cif::tie(child, parent, link_group_id) = gl.get("child_name", "parent_name", "link_group_id");
+			auto &&[child, parent, link_group_id] = gl.get<std::string, std::string, int>("child_name", "parent_name", "link_group_id");
 
 			auto civ = m_validator.get_validator_for_item(child);
 			if (civ == nullptr)
@@ -350,7 +434,7 @@ class dictionary_parser : public parser
 			if (not linkIndex.count(key))
 			{
 				linkIndex[key] = linkKeys.size();
-				linkKeys.push_back({});
+				linkKeys.emplace_back();
 			}
 
 			std::size_t ix = linkIndex.at(key);
@@ -378,7 +462,7 @@ class dictionary_parser : public parser
 				if (not linkIndex.count(key))
 				{
 					linkIndex[key] = linkKeys.size();
-					linkKeys.push_back({});
+					linkKeys.emplace_back();
 				}
 
 				std::size_t ix = linkIndex.at(key);
@@ -399,10 +483,39 @@ class dictionary_parser : public parser
 			// look up the label
 			for (auto r : linkedGroup.find("category_id"_key == link.m_child_category and "link_group_id"_key == link.m_link_group_id))
 			{
-				link.m_link_group_label = r["label"].as<std::string>();
+				link.m_link_group_label = r["label"].get<std::string>();
 				break;
 			}
 
+			// A last validation, link ends should both point to the same time
+
+			auto childCatValidator = m_validator.get_validator_for_category(link.m_child_category);
+			auto parentCatValidator = m_validator.get_validator_for_category(link.m_parent_category);
+
+			if (childCatValidator == nullptr)
+				throw std::runtime_error(std::format("Invalid dictionary, undefined category {} in link {}", link.m_child_category, link.m_link_group_id));
+			if (parentCatValidator == nullptr)
+				throw std::runtime_error(std::format("Invalid dictionary, undefined category {} in link {}", link.m_parent_category, link.m_link_group_id));
+
+			for (size_t ix = 0; ix < link.m_child_keys.size(); ++ix)
+			{
+				auto childItemValidator = childCatValidator->get_validator_for_item(link.m_child_keys[ix]);
+				auto parentItemValidator = parentCatValidator->get_validator_for_item(link.m_parent_keys[ix]);
+
+				if (childItemValidator == nullptr)
+					throw std::runtime_error(std::format("Invalid dictionary, in link group {} the item {} is not know in category {}",
+						link.m_link_group_id, link.m_child_keys[ix], link.m_child_category));
+				if (parentItemValidator == nullptr)
+					throw std::runtime_error(std::format("Invalid dictionary, in link group {} the item {} is not know in category {}",
+						link.m_link_group_id, link.m_parent_keys[ix], link.m_parent_category));
+
+				if (childItemValidator->m_type == nullptr)
+					const_cast<item_validator *>(childItemValidator)->m_type = parentItemValidator->m_type;
+				else if (childItemValidator->m_type != parentItemValidator->m_type)
+					throw std::runtime_error(std::format("Invalid dictionary, in link group {} the items _{}.{}/_{}.{} do not have the same type",
+						link.m_link_group_id, link.m_parent_category, link.m_parent_keys[ix], link.m_child_category, link.m_child_keys[ix]));
+			}
+
 			m_validator.add_link_validator(std::move(link));
 		}
 
@@ -412,7 +525,7 @@ class dictionary_parser : public parser
 		{
 			for (auto &iv : cv.m_item_validators)
 			{
-				if (iv.m_type == nullptr and cif::VERBOSE >= 0)
+				if (iv.m_type == nullptr and VERBOSE >= 0)
 					std::cerr << "Missing item_type for " << iv.m_item_name << '\n';
 			}
 		}

src/file.cpp

@@ -24,8 +24,16 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "cif++/file.hpp"
-#include "cif++/gzio.hpp"
+#include "cif++/cif++.hpp"
+
+#include <cassert>
+#include <exception>
+#include <filesystem>
+#include <istream>
+#include <list>
+#include <stdexcept>
+#include <string_view>
+#include <tuple>
 
 namespace cif
 {
@@ -46,8 +54,16 @@ bool file::is_valid()
 {
 	bool result = not empty();
 
-	for (auto &d : *this)
-		result = d.is_valid() and result;
+	for (bool first = true; auto &d : *this)
+	{
+		if (first)
+		{
+			result = d.is_valid() and result;
+			first = false;
+		}
+		else if (d.get_validator() != nullptr)
+			result = d.is_valid() and result;
+	}
 
 	if (result)
 		result = validate_links();
@@ -67,13 +83,13 @@ bool file::validate_links() const
 
 bool file::contains(std::string_view name) const
 {
-	return std::find_if(begin(), end(), [name](const datablock &db)
+	return std::ranges::find_if(*this, [name](const datablock &db)
 			   { return iequals(db.name(), name); }) != end();
 }
 
 datablock &file::operator[](std::string_view name)
 {
-	auto i = std::find_if(begin(), end(), [name](const datablock &c)
+	auto i = std::ranges::find_if(*this, [name](const datablock &c)
 		{ return iequals(c.name(), name); });
 
 	if (i != end())
@@ -86,7 +102,7 @@ datablock &file::operator[](std::string_view name)
 const datablock &file::operator[](std::string_view name) const
 {
 	static const datablock s_empty;
-	auto i = std::find_if(begin(), end(), [name](const datablock &c)
+	auto i = std::ranges::find_if(*this, [name](const datablock &c)
 		{ return iequals(c.name(), name); });
 	return i == end() ? s_empty : *i;
 }
@@ -130,30 +146,6 @@ void file::load(const std::filesystem::path &p)
 	}
 }
 
-void file::load(const std::filesystem::path &p, const validator &v)
-{
-	gzio::ifstream in(p);
-	if (not in.is_open())
-		throw std::runtime_error("Could not open file '" + p.string() + '\'');
-
-	try
-	{
-		load(in, v);
-	}
-	catch (const std::exception &)
-	{
-		throw_with_nested(std::runtime_error("Error reading file '" + p.string() + '\''));
-	}
-}
-
-void file::load(std::istream &is, const validator &v)
-{
-	parser p(is, *this);
-	p.parse_file();
-	for (auto &db : *this)
-		db.set_validator(&v);
-}
-
 void file::load(std::istream &is)
 {
 	parser p(is, *this);

src/item.cpp

@@ -24,45 +24,275 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "cif++/row.hpp"
+#include "cif++/item.hpp"
 
+#include "cif++/row.hpp"
+#include "cif++/text.hpp"
+
+#include <algorithm>
 #include <cassert>
+#include <charconv>
+#include <cmath>
+#include <compare>
+#include <cstdint>
+#include <ostream>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <system_error>
+#include <utility>
+#include <vector>
 
 namespace cif
 {
 
-const item_handle item_handle::s_null_item;
-row_handle s_null_row_handle;
-
-item_handle::item_handle()
-	: m_item_ix(std::numeric_limits<uint16_t>::max())
-	, m_row_handle(s_null_row_handle)
+bool item_handle::empty() const
 {
+	return m_item_ix >= m_row.size() or m_row[m_item_ix].empty();
 }
 
-std::string_view item_handle::text() const
+item_value &item_handle::value()
 {
-	if (not m_row_handle.empty())
+	assert(m_item_ix < m_row.size());
+	return m_row.operator[](m_item_ix);
+}
+
+const item_value &item_handle::value() const
+{
+	assert(m_item_ix < m_row.size());
+	return m_row.operator[](m_item_ix);
+}
+
+void swap(item_handle a, item_handle b) noexcept
+{
+	item_value v(std::move(a.value()));
+	a.value() = std::move(b.value());
+	b.value() = std::move(v);
+}
+
+void item_handle::set(item_value value, bool updateLinked)
+{
+	row_handle rh{ m_category, m_row };
+	rh.assign(m_item_ix, std::move(value), updateLinked);
+}
+
+int item_value::compare(const item_value &b, bool ignore_case) const noexcept
+{
+	int d = static_cast<int>(m_data.m_type) - static_cast<int>(b.m_data.m_type);
+
+	if (d == 0)
 	{
-		auto iv = m_row_handle.m_row->get(m_item_ix);
-		if (iv != nullptr)
-			return iv->text();
+		switch (m_data.m_type)
+		{
+			using enum item_value_type;
+
+			case INT:
+				d = m_data.m_value.m_integer - b.m_data.m_value.m_integer;
+				break;
+			case FLOAT:
+				// stupid comparison based on chopped textual representation
+				if (m_data.m_len > 0 or b.m_data.m_len > 0)
+				{
+					double fa = m_data.m_value.m_float;
+					double fb = b.m_data.m_value.m_float;
+
+					auto delta = std::abs(fa - fb);
+					if (delta == 0 or std::isnan(delta))
+						d = 0;
+					else if (m_data.m_len and b.m_data.m_len)
+					{
+						auto epsilon = std::pow(10.0f, -1.0f * std::min(m_data.m_len, b.m_data.m_len));
+						if (delta > epsilon)
+							d = fa < fb ? -1 : 1;
+						else
+							d = 0;
+					}
+					else
+					{
+						auto dp = (m_data.m_value.m_float <=> b.m_data.m_value.m_float);
+						if (dp == std::partial_ordering::less)
+							d = -1;
+						else if (dp == std::partial_ordering::greater)
+							d = 1;
+					}
+				}
+				else
+				{
+					auto dp = (m_data.m_value.m_float <=> b.m_data.m_value.m_float);
+					if (dp == std::partial_ordering::less)
+						d = -1;
+					else if (dp == std::partial_ordering::greater)
+						d = 1;
+				}
+				break;
+			case TEXT:
+				d = m_data.sv().compare(b.m_data.sv());
+				break;
+			default:;
+		}
+	}
+	else if (is_number() and b.is_number())
+	{
+		std::partial_ordering dp = std::partial_ordering::equivalent;
+
+		if (is_number_float())
+			dp = m_data.m_value.m_float <=> b.m_data.m_value.m_integer;
+		else /*  if (is_number_int()) */
+			dp = m_data.m_value.m_integer <=> b.m_data.m_value.m_float;
+
+		if (dp == std::partial_ordering::less)
+			d = -1;
+		else if (dp == std::partial_ordering::greater)
+			d = 1;
+		else
+			d = 0;
+	}
+	else if (is_number_int() and b.is_string())
+		d = str().compare(b.m_data.sv());
+	else if (is_string() and b.is_number_int())
+		d = m_data.sv().compare(b.str());
+
+	return d;
+}
+
+std::string item_value::str() const
+{
+	switch (m_data.m_type)
+	{
+		using enum item_value_type;
+
+		case MISSING:
+			return "?";
+
+		case INAPPLICABLE:
+			return ".";
+
+		case TEXT:
+			return std::string{ m_data.sv() };
+
+		case INT:
+		{
+			char s[32];
+			std::to_chars_result r = std::to_chars(s, s + sizeof(s), m_data.m_value.m_integer);
+			return r.ec == std::errc{} ? std::string{ s, r.ptr } : "*****";
+		}
+
+		case FLOAT:
+		{
+			char s[32];
+
+			std::to_chars_result r;
+
+			if (m_data.m_len)
+			{
+				r = std::to_chars(s, s + sizeof(s), m_data.m_value.m_float, std::chars_format::fixed, m_data.m_len);
+				if (r.ec != std::errc{})
+					r = std::to_chars(s, s + sizeof(s), m_data.m_value.m_float);
+			}
+			else
+				r = std::to_chars(s, s + sizeof(s), m_data.m_value.m_float);
+
+			return r.ec == std::errc{} ? std::string{ s, r.ptr } : "*****";
+		}
 	}
 
-	return {};
+	std::unreachable();
 }
 
-void item_handle::assign_value(std::string_view value)
+// void const_item_handle::assign_value(const item_value &value)
+// {
+// 	assert(not m_row_handle.empty());
+// 	m_row_handle.assign(m_item_ix, value, true);
+// }
+
+std::ostream &operator<<(std::ostream &os, const item_value &v)
 {
-	assert(not m_row_handle.empty());
-	m_row_handle.assign(m_item_ix, value, true);
+	switch (v.type())
+	{
+		using enum item_value_type;
+
+		case INT: os << v.m_data.m_value.m_integer; break;
+		case FLOAT: os << v.m_data.m_value.m_float; break;
+		case TEXT: os << v.m_data.sv(); break;
+		case MISSING: os << '?'; break;
+		case INAPPLICABLE: os << '.'; break;
+		default: os.setstate(std::ios::failbit);
+	}
+
+	return os;
 }
 
-void item_handle::swap(item_handle &b)
+void item_value::cast_to_int()
 {
-	assert(m_item_ix == b.m_item_ix);
-	// assert(&m_row_handle.m_category == &b.m_row_handle.m_category);
-	m_row_handle.swap(m_item_ix, b.m_row_handle);
+	switch (type())
+	{
+		using enum item_value_type;
+
+		case INT:
+			break;
+
+		case FLOAT:
+			*this = std::rint(m_data.m_value.m_float);
+			break;
+
+		case TEXT:
+		{
+			auto s = sv();
+			int64_t v;
+
+			auto sp = s.data();
+			if (*sp == '+')
+				++sp;
+
+			auto [ptr, ec] = cif::from_chars(sp, s.data() + s.size(), v);
+			if (ec != std::errc{})
+				throw std::system_error(std::make_error_code(ec), "attempt to cast value to integer failed");
+			if (ptr != s.data() + s.size())
+				throw std::runtime_error("attempt to cast value to integer failed, trailing data");
+
+			*this = v;
+			break;
+		}
+
+		default:
+			break;
+	}
 }
 
+void item_value::cast_to_float()
+{
+	switch (type())
+	{
+		using enum item_value_type;
+
+		case INT:
+			*this = static_cast<double>(m_data.m_value.m_integer);
+			break;
+
+		case FLOAT:
+			break;
+
+		case TEXT:
+		{
+			auto s = sv();
+			double v;
+			auto [ptr, ec] = cif::from_chars(s.data(), s.data() + s.size(), v);
+			if (ec != std::errc{})
+				throw std::system_error(std::make_error_code(ec), "attempt to cast value to integer failed");
+			if (ptr != s.data() + s.size())
+				throw std::runtime_error("attempt to cast value to integer failed, trailing data");
+			*this = v;
+			break;
+		}
+
+		default:
+			break;
+	}
 }
+
+void item_value::cast_to_string()
+{
+	*this = str();
+}
+
+} // namespace cif

src/parser.cpp

@@ -24,15 +24,20 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "cif++/cif++.hpp"
 #include "cif++/utilities.hpp"
-#include "cif++/forward_decl.hpp"
-#include "cif++/parser.hpp"
-#include "cif++/file.hpp"
 
 #include <cassert>
+#include <cctype>
+#include <cstdint>
 #include <iostream>
-#include <map>
-#include <stack>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <system_error>
+#include <tuple>
+#include <utility>
+#include <vector>
 
 namespace cif
 {
@@ -42,7 +47,7 @@ namespace cif
 class reserved_words_automaton
 {
   public:
-	reserved_words_automaton() {}
+	reserved_words_automaton() = default;
 
 	enum move_result
 	{
@@ -56,14 +61,14 @@ class reserved_words_automaton
 		stop
 	};
 
-	constexpr bool finished() const
+	[[nodiscard]] constexpr bool finished() const
 	{
-		return m_state <= 0; 
+		return m_state <= 0;
 	}
 
-	constexpr bool matched() const
+	[[nodiscard]] constexpr bool matched() const
 	{
-		return m_state < 0; 
+		return m_state < 0;
 	}
 
 	constexpr move_result move(int ch)
@@ -75,7 +80,7 @@ class reserved_words_automaton
 			case 0:
 				break;
 
-			case -1:		// data_
+			case -1: // data_
 				if (sac_parser::is_non_blank(ch))
 					m_seen_trailing_chars = true;
 				else if (m_seen_trailing_chars)
@@ -84,15 +89,15 @@ class reserved_words_automaton
 					result = no_keyword;
 				break;
 
-			case -2:		// global_
+			case -2: // global_
 				result = sac_parser::is_non_blank(ch) ? no_keyword : global;
 				break;
 
-			case -3:		// loop_
+			case -3: // loop_
 				result = sac_parser::is_non_blank(ch) ? no_keyword : loop;
 				break;
 
-			case -4:		// save_
+			case -4: // save_
 				if (sac_parser::is_non_blank(ch))
 					m_seen_trailing_chars = true;
 				else if (m_seen_trailing_chars)
@@ -101,10 +106,10 @@ class reserved_words_automaton
 					result = save;
 				break;
 
-			case -5:		// stop_
+			case -5: // stop_
 				result = sac_parser::is_non_blank(ch) ? no_keyword : stop;
 				break;
-			
+
 			default:
 				assert(m_state > 0 and m_state < NODE_COUNT);
 
@@ -137,17 +142,17 @@ class reserved_words_automaton
 	static constexpr struct node
 	{
 		int16_t ch;
-		int8_t next_match;
-		int8_t next_nomatch;
+		int next_match;
+		int next_nomatch;
 	} s_dag[] = {
 		{ 0 },
-		{ 'D',  5, 2 },
-		{ 'G',  9, 3 },
+		{ 'D', 5, 2 },
+		{ 'G', 9, 3 },
 		{ 'L', 15, 4 },
 		{ 'S', 19, 0 },
-		{ 'A',  6, 0 },
-		{ 'T',  7, 0 },
-		{ 'A',  8, 0 },
+		{ 'A', 6, 0 },
+		{ 'T', 7, 0 },
+		{ 'A', 8, 0 },
 		{ '_', -1, 0 },
 		{ 'L', 10, 0 },
 		{ 'O', 11, 0 },
@@ -155,7 +160,7 @@ class reserved_words_automaton
 		{ 'A', 13, 0 },
 		{ 'L', 14, 0 },
 		{ '_', -2, 0 },
-		{ 'O', 16, 0},
+		{ 'O', 16, 0 },
 		{ 'O', 17, 0 },
 		{ 'P', 18, 0 },
 		{ '_', -3, 0 },
@@ -238,7 +243,7 @@ int sac_parser::get_next_char()
 		}
 		else if (result == '\n')
 			++m_line_nr;
-		
+
 		m_token_buffer.push_back(std::char_traits<char>::to_char_type(result));
 	}
 
@@ -277,6 +282,9 @@ sac_parser::CIFToken sac_parser::get_next_token()
 	m_token_buffer.clear();
 	m_token_value = {};
 
+	bool negative = false;
+	m_float_precision = 0;
+
 	reserved_words_automaton dag;
 
 	while (result == CIFToken::UNKNOWN)
@@ -285,53 +293,73 @@ sac_parser::CIFToken sac_parser::get_next_token()
 
 		switch (state)
 		{
-			case State::Start:
+			using enum State;
+
+			case Start:
 				if (ch == kEOF)
 					result = CIFToken::END_OF_FILE;
 				else if (ch == '\n')
 				{
 					m_bol = true;
-					state = State::White;
+					state = White;
 				}
 				else if (ch == ' ' or ch == '\t')
-					state = State::White;
+					state = White;
 				else if (ch == '#')
-					state = State::Comment;
+					state = Comment;
 				else if (ch == '_')
-					state = State::ItemName;
+					state = ItemName;
 				else if (ch == ';' and m_bol)
-					state = State::TextItem;
+				{
+					if (m_backslash_strings)
+						state = TextItemBS;
+					else
+						state = TextItem;
+				}
 				else if (ch == '?')
-					state = State::QuestionMark;
+					state = QuestionMark;
 				else if (ch == '\'' or ch == '"')
 				{
 					quoteChar = ch;
-					state = State::QuotedString;
+					state = QuotedString;
 				}
 				else if (dag.move(ch) == reserved_words_automaton::undefined)
-					state = State::Reserved;
+					state = Reserved;
+				else if (ch == '+' or ch == '-')
+				{
+					negative = true;
+					state = Numeric_Integer;
+				}
+				else if (ch == '0')
+					state = Numeric_Zero;
+				else if (ch >= '1' and ch <= '9')
+					state = Numeric_Integer;
+				else if (ch == '.')
+					state = Numeric_Float;
 				else
-					state = State::Value;
+					state = Value;
 				break;
 
-			case State::White:
+			case White:
 				if (ch == kEOF)
 					result = CIFToken::END_OF_FILE;
 				else if (not is_space(ch))
 				{
-					state = State::Start;
+					state = Start;
 					retract();
 					m_token_buffer.clear();
 				}
 				else
 					m_bol = (ch == '\n');
 				break;
-			
-			case State::Comment:
+
+			case Comment:
 				if (ch == '\n')
 				{
-					state = State::Start;
+					state = Start;
 					m_bol = true;
+					if (m_token_buffer.size() == 3 and m_token_buffer == std::vector{ '#', '\\', '\n' })
+						m_backslash_strings = true;
 					m_token_buffer.clear();
 				}
 				else if (ch == kEOF)
@@ -339,34 +367,58 @@ sac_parser::CIFToken sac_parser::get_next_token()
 				else if (not is_any_print(ch))
 					error("invalid character in comment");
 				break;
-			
-			case State::QuestionMark:
+
+			case QuestionMark:
 				if (not is_non_blank(ch))
 				{
 					retract();
-					result = CIFToken::VALUE;
+					result = CIFToken::VALUE_UNKNOWN;
 				}
 				else
-					state = State::Value;
+					state = Value;
 				break;
 
-			case State::TextItem:
+			case TextItemBS:
+				if (ch == '\\')
+				{
+					state = TextItemBS2;
+					break;
+				}
+				[[fallthrough]];
+
+			case TextItem:
 				if (ch == '\n')
-					state = State::TextItemNL;
+					state = TextItemNL;
 				else if (ch == kEOF)
 					error("unterminated textfield");
-				else if (not is_any_print(ch) and cif::VERBOSE > 2)
-					warning("invalid character in text field '" + std::string({static_cast<char>(ch)}) + "' (" + std::to_string((int)ch) + ")");
+				else if (not is_any_print(ch) and VERBOSE > 2)
+					warning("invalid character in text field '" + std::string({ static_cast<char>(ch) }) + "' (" + std::to_string(ch) + ")");
 				break;
 
-			case State::TextItemNL:
+			case TextItemBS2:
+				if (ch == '\n')
+				{
+					if (m_token_buffer[m_token_buffer.size() - 2] == '\\')
+					{
+						m_token_buffer.pop_back();
+						m_token_buffer.pop_back();
+					}
+					state = TextItemBSNL;
+				}
+				else if (ch == kEOF)
+					error("unterminated textfield");
+				else if (not is_any_print(ch) and VERBOSE > 2)
+					warning("invalid character in text field '" + std::string({ static_cast<char>(ch) }) + "' (" + std::to_string(ch) + ")");
+				break;
+
+			case TextItemBSNL:
 				if (is_text_lead(ch) or ch == ' ' or ch == '\t')
-					state = State::TextItem;
+					state = TextItemBS;
 				else if (ch == ';')
 				{
 					assert(m_token_buffer.size() >= 2);
 					m_token_value = std::string_view(m_token_buffer.data() + 1, m_token_buffer.size() - 3);
-					result = CIFToken::VALUE;
+					result = CIFToken::VALUE_CHARSTRING;
 				}
 				else if (ch == kEOF)
 					error("unterminated textfield");
@@ -374,20 +426,35 @@ sac_parser::CIFToken sac_parser::get_next_token()
 					error("invalid character in text field");
 				break;
 
-			case State::QuotedString:
+			case TextItemNL:
+				if (is_text_lead(ch) or ch == ' ' or ch == '\t')
+					state = TextItem;
+				else if (ch == ';')
+				{
+					assert(m_token_buffer.size() >= 2);
+					m_token_value = std::string_view(m_token_buffer.data() + 1, m_token_buffer.size() - 3);
+					result = CIFToken::VALUE_TEXTFIELD;
+				}
+				else if (ch == kEOF)
+					error("unterminated textfield");
+				else if (ch != '\n')
+					error("invalid character in text field");
+				break;
+
+			case QuotedString:
 				if (ch == kEOF)
 					error("unterminated quoted string");
 				else if (ch == quoteChar)
-					state = State::QuotedStringQuote;
-				else if (not is_any_print(ch) and cif::VERBOSE > 2)
-					warning("invalid character in quoted string: '" + std::string({static_cast<char>(ch)}) + "' (" + std::to_string((int)ch) + ")");
+					state = QuotedStringQuote;
+				else if (not is_any_print(ch) and VERBOSE > 2)
+					warning("invalid character in quoted string: '" + std::string({ static_cast<char>(ch) }) + "' (" + std::to_string(ch) + ")");
 				break;
 
-			case State::QuotedStringQuote:
+			case QuotedStringQuote:
 				if (is_white(ch))
 				{
 					retract();
-					result = CIFToken::VALUE;
+					result = CIFToken::VALUE_CHARSTRING;
 					if (m_token_buffer.size() < 2)
 						error("Invalid quoted string token");
 
@@ -396,14 +463,14 @@ sac_parser::CIFToken sac_parser::get_next_token()
 				else if (ch == quoteChar)
 					;
 				else if (is_any_print(ch))
-					state = State::QuotedString;
+					state = QuotedString;
 				else if (ch == kEOF)
 					error("unterminated quoted string");
 				else
 					error("invalid character in quoted string");
 				break;
 
-			case State::ItemName:
+			case ItemName:
 				if (not is_non_blank(ch))
 				{
 					retract();
@@ -412,7 +479,7 @@ sac_parser::CIFToken sac_parser::get_next_token()
 				}
 				break;
 
-			case State::Reserved:
+			case Reserved:
 				switch (dag.move(ch))
 				{
 					case reserved_words_automaton::undefined:
@@ -422,11 +489,11 @@ sac_parser::CIFToken sac_parser::get_next_token()
 						if (not is_non_blank(ch))
 						{
 							retract();
-							result = CIFToken::VALUE;
+							result = CIFToken::VALUE_CHARSTRING;
 							m_token_value = std::string_view(m_token_buffer.data(), m_token_buffer.size());
 						}
 						else
-							state = State::Value;
+							state = Value;
 						break;
 
 					case reserved_words_automaton::data:
@@ -463,11 +530,90 @@ sac_parser::CIFToken sac_parser::get_next_token()
 				}
 				break;
 
-			case State::Value:
+			case Numeric_Zero:
 				if (not is_non_blank(ch))
 				{
 					retract();
-					result = CIFToken::VALUE;
+					result = CIFToken::VALUE_NUMERIC_INTEGER;
+				}
+				else if (ch == '.')
+					state = Numeric_Float;
+				else
+					state = Value;
+				break;
+
+			case Numeric_Integer:
+				if (ch == '.')
+					state = Numeric_Float;
+				else if (ch == 'e' or ch == 'E')
+					state = Numeric_Exponent1;
+				else if (not is_non_blank(ch))
+				{
+					retract();
+					if (m_token_buffer.size() == 1 and negative)
+					{
+						result = CIFToken::VALUE_CHARSTRING; // A single hyphen...
+						m_token_value = std::string_view{ m_token_buffer.data(), m_token_buffer.data() + 1 };
+					}
+					else
+						result = CIFToken::VALUE_NUMERIC_INTEGER;
+				}
+				else if (ch < '0' or ch > '9')
+					state = Value;
+				break;
+
+			case Numeric_Float:
+				if (not is_non_blank(ch))
+				{
+					retract();
+					if (m_token_buffer.size() == 1)
+						result = CIFToken::VALUE_INAPPLICABLE;
+					else
+						result = CIFToken::VALUE_NUMERIC_FLOAT;
+				}
+				else if (ch == 'e' or ch == 'E')
+					state = Numeric_Exponent1;
+				else if (ch < '0' or ch > '9')
+					state = Value;
+				else
+					++m_float_precision;
+				break;
+
+			case Numeric_Exponent1:
+				if (not is_non_blank(ch))
+				{
+					retract();
+					result = CIFToken::VALUE_CHARSTRING;
+					m_token_value = std::string_view(m_token_buffer.data(), m_token_buffer.size());
+				}
+				else if (ch == '+' or ch == '-' or (ch >= '0' and ch <= '9'))
+					state = Numeric_Exponent2;
+				else
+				{
+					// warning(std::format("parsing {}:  Invalid floating point value, expected digit or sign character", std::string_view{ m_token_buffer.data(), m_token_buffer.size() }));
+					state = Value;
+				}
+				break;
+
+			case Numeric_Exponent2:
+				if (not is_non_blank(ch))
+				{
+					retract();
+					result = CIFToken::VALUE_NUMERIC_FLOAT;
+				}
+				else if (ch < '0' or ch > '9')
+				{
+					if (VERBOSE > 0)
+						// warning(std::format("parsing {}:  Invalid floating point value, expected digit or sign character", std::string_view{ m_token_buffer.data(), m_token_buffer.size() }));
+						state = Value;
+				}
+				break;
+
+			case Value:
+				if (not is_non_blank(ch))
+				{
+					retract();
+					result = CIFToken::VALUE_CHARSTRING;
 					m_token_value = std::string_view(m_token_buffer.data(), m_token_buffer.size());
 					break;
 				}
@@ -480,12 +626,38 @@ sac_parser::CIFToken sac_parser::get_next_token()
 		}
 	}
 
-	if (VERBOSE >= 5)
+	// if (VERBOSE >= 5)
+	// {
+	// 	std::cerr << get_token_name(result);
+	// 	if (result != CIFToken::END_OF_FILE)
+	// 		std::cerr << " " << std::quoted(m_token_value);
+	// 	std::cerr << '\n';
+	// }
+
+	if (result == CIFToken::VALUE_NUMERIC_INTEGER)
 	{
-		std::cerr << get_token_name(result);
-		if (result != CIFToken::END_OF_FILE)
-			std::cerr << " " << std::quoted(m_token_value);
-		std::cerr << '\n';
+		// Avoid interpreting phone numbers as integers, TODO: check if this is an issue
+		auto [ptr, ec] = from_chars(m_token_buffer.data(), m_token_buffer.data() + m_token_buffer.size(), m_token_value_int);
+		if (ec != std::errc{})
+		{
+			if (cif::VERBOSE > 0)
+				std::clog << "Invalid integer value: " << std::make_error_code(ec).message() << '\n';
+
+			result = CIFToken::VALUE_CHARSTRING;
+			m_token_value = std::string_view(m_token_buffer.data(), m_token_buffer.size());
+		}
+	}
+	else if (result == CIFToken::VALUE_NUMERIC_FLOAT)
+	{
+		auto [ptr, ec] = from_chars(m_token_buffer.data(), m_token_buffer.data() + m_token_buffer.size(), m_token_value_float);
+		if (ec != std::errc{})
+		{
+			if (cif::VERBOSE > 0)
+				std::clog << "Invalid floating point value: " << std::make_error_code(ec).message() << '\n';
+
+			result = CIFToken::VALUE_CHARSTRING;
+			m_token_value = std::string_view(m_token_buffer.data(), m_token_buffer.size());
+		}
 	}
 
 	return result;
@@ -540,6 +712,7 @@ bool sac_parser::parse_single_datablock(const std::string &datablock)
 						if (bol)
 							state = qstring;
 						break;
+					default:;
 				}
 				break;
 
@@ -633,6 +806,7 @@ sac_parser::datablock_index sac_parser::index_datablocks()
 						if (bol)
 							state = qstring;
 						break;
+					default:;
 				}
 				break;
 
@@ -661,7 +835,7 @@ sac_parser::datablock_index sac_parser::index_datablocks()
 			case data:
 				if (dblk[si] == 0 and is_non_blank(ch))
 				{
-					datablock = {static_cast<char>(ch)};
+					datablock = { static_cast<char>(ch) };
 					state = data_name;
 				}
 				else if (dblk[si++] != ch)
@@ -670,7 +844,7 @@ sac_parser::datablock_index sac_parser::index_datablocks()
 
 			case data_name:
 				if (is_non_blank(ch))
-					datablock.insert(datablock.end(), (char)std::toupper(ch));
+					datablock.insert(datablock.end(), static_cast<char>(std::toupper(ch)));
 				else if (is_space(ch))
 				{
 					if (not datablock.empty())
@@ -738,14 +912,17 @@ void sac_parser::parse_global()
 	while (m_lookahead == CIFToken::ITEM_NAME)
 	{
 		match(CIFToken::ITEM_NAME);
-		match(CIFToken::VALUE);
+		if (m_lookahead >= CIFToken::VALUE_INAPPLICABLE)
+			match(m_lookahead);
+		else
+			match(CIFToken::VALUE_CHARSTRING);
 	}
 }
 
 void sac_parser::parse_datablock()
 {
 	static const std::string kUnitializedCategory("<invalid>");
-	std::string cat = kUnitializedCategory;	// intial value acts as a guard for empty category names
+	std::string cat = kUnitializedCategory; // intial value acts as a guard for empty category names
 
 	while (m_lookahead == CIFToken::LOOP or m_lookahead == CIFToken::ITEM_NAME or m_lookahead == CIFToken::SAVE_NAME)
 	{
@@ -777,14 +954,38 @@ void sac_parser::parse_datablock()
 					match(CIFToken::ITEM_NAME);
 				}
 
-				while (m_lookahead == CIFToken::VALUE)
+				while (m_lookahead >= CIFToken::VALUE_INAPPLICABLE)
 				{
 					produce_row();
 
 					for (auto item_name : item_names)
 					{
-						produce_item(cat, item_name, m_token_value);
-						match(CIFToken::VALUE);
+						switch (m_lookahead)
+						{
+							case CIFToken::VALUE_INAPPLICABLE:
+								produce_item(cat, item_name, item_value_type::INAPPLICABLE);
+								match(m_lookahead);
+								break;
+							case CIFToken::VALUE_UNKNOWN:
+								produce_item(cat, item_name, item_value_type::MISSING);
+								match(m_lookahead);
+								break;
+							case CIFToken::VALUE_NUMERIC_INTEGER:
+								produce_item(cat, item_name, m_token_value_int);
+								match(m_lookahead);
+								break;
+							case CIFToken::VALUE_NUMERIC_FLOAT:
+								produce_item(cat, item_name, { m_token_value_float, m_float_precision });
+								match(m_lookahead);
+								break;
+							case CIFToken::VALUE_CHARSTRING:
+							case CIFToken::VALUE_TEXTFIELD:
+								produce_item(cat, item_name, m_token_value);
+								match(m_lookahead);
+								break;
+							default:;
+								match(CIFToken::VALUE_CHARSTRING);
+						}
 					}
 				}
 
@@ -806,9 +1007,33 @@ void sac_parser::parse_datablock()
 
 				match(CIFToken::ITEM_NAME);
 
-				produce_item(cat, itemName, m_token_value);
+				switch (m_lookahead)
+				{
+					case CIFToken::VALUE_INAPPLICABLE:
+						produce_item(cat, itemName, item_value_type::INAPPLICABLE);
+						match(CIFToken::VALUE_INAPPLICABLE);
+						break;
+					case CIFToken::VALUE_UNKNOWN:
+						produce_item(cat, itemName, item_value_type::MISSING);
+						match(CIFToken::VALUE_UNKNOWN);
+						break;
+					case CIFToken::VALUE_NUMERIC_INTEGER:
+						produce_item(cat, itemName, m_token_value_int);
+						match(CIFToken::VALUE_NUMERIC_INTEGER);
+						break;
+					case CIFToken::VALUE_NUMERIC_FLOAT:
+						produce_item(cat, itemName, { m_token_value_float, m_float_precision });
+						match(CIFToken::VALUE_NUMERIC_FLOAT);
+						break;
+					case CIFToken::VALUE_CHARSTRING:
+					case CIFToken::VALUE_TEXTFIELD:
+						produce_item(cat, itemName, m_token_value);
+						match(m_lookahead);
+						break;
+					default:
+						match(CIFToken::VALUE_CHARSTRING);
+				}
 
-				match(CIFToken::VALUE);
 				break;
 			}
 
@@ -847,7 +1072,9 @@ void parser::produce_category(std::string_view name)
 	if (VERBOSE >= 4)
 		std::cerr << "producing category " << name << '\n';
 
-	const auto &[cat, ignore] = m_datablock->emplace(name);
+	const auto &[cat, is_new] = m_datablock->emplace(name);
+	if (is_new and m_validator)
+		cat->set_validator(m_validator, *m_datablock);
 	m_category = &*cat;
 }
 
@@ -859,12 +1086,11 @@ void parser::produce_row()
 	if (m_category == nullptr)
 		error("inconsistent categories in loop_");
 
-	m_category->emplace({});
-	m_row = m_category->back();
-	// m_row.lineNr(m_line_nr);
+	auto i = m_category->emplace({});
+	m_row = *i;
 }
 
-void parser::produce_item(std::string_view category, std::string_view item, std::string_view value)
+void parser::produce_item(std::string_view category, std::string_view item, item_value value)
 {
 	if (VERBOSE >= 4)
 		std::cerr << "producing _" << category << '.' << item << " -> " << value << '\n';
@@ -872,7 +1098,20 @@ void parser::produce_item(std::string_view category, std::string_view item, std:
 	if (m_category == nullptr or not iequals(category, m_category->name()))
 		error("inconsistent categories in loop_");
 
-	m_row[item] = m_token_value;
+	if (value.is_number())
+	{
+		auto cv = m_category->get_cat_validator();
+		if (cv != nullptr)
+		{
+			if (auto iv = cv->get_validator_for_item(item))
+			{
+				if (auto tv = iv->m_type; tv and tv->m_primitive_type != DDL_PrimitiveType::Numb)
+					value = std::string_view{ m_token_buffer.data(), m_token_buffer.data() + m_token_buffer.size() };
+			}
+		}
+	}
+
+	m_row[item].set(value, false);
 }
 
 } // namespace cif

src/pdb/pdb2cif_remark_3.cpp

@@ -26,10 +26,19 @@
 
 #include "pdb2cif_remark_3.hpp"
 
-#include <cif++.hpp>
+#include "cif++/cif++.hpp"
 
-#include <map>
-#include <set>
+#include <algorithm>
+#include <cstddef>
+#include <cctype>
+#include <exception>
+#include <iostream>
+#include <memory>
+#include <optional>
+#include <utility>
+#include <vector>
+
+// NOLINTBEGIN(bugprone-empty-catch)
 
 namespace cif::pdb
 {
@@ -153,7 +162,7 @@ const TemplateLine kBusterTNT_Template[] = {
 class BUSTER_TNT_Remark3Parser : public Remark3Parser
 {
   public:
-	BUSTER_TNT_Remark3Parser(const std::string &name, const std::string &expMethod, PDBRecord *r, cif::datablock &db)
+	BUSTER_TNT_Remark3Parser(std::string name, std::string expMethod, PDBRecord *r, cif::datablock &db)
 		: Remark3Parser(name, expMethod, r, db,
 			  kBusterTNT_Template, sizeof(kBusterTNT_Template) / sizeof(TemplateLine),
 			  std::regex(R"((BUSTER(?:-TNT)?)(?: (\d+(?:\..+)?))?)"))
@@ -237,18 +246,28 @@ const TemplateLine kCNS_Template[] = {
 	/* 72 */ { R"(METHOD USED\s*:\s*(.+))", 1, "refine", { "solvent_model_details" } },
 	/* 73 */ { R"(KSOL\s*:\s*(.+))", 1, "refine", { "solvent_model_param_ksol" } },
 	/* 74 */ { R"(BSOL\s*:\s*(.+))", 1, "refine", { "solvent_model_param_bsol" } },
-	/* 75 */ { R"(NCS MODEL\s*:\s*(.+))", 1, /* "refine_ls_restr_ncs", { "ncs_model_details" } */ },
+	/* 75 */ { R"(NCS MODEL\s*:\s*(.+))",
+		1,
+		/* "refine_ls_restr_ncs", { "ncs_model_details" } */ },
 	/* 76 */ { R"(NCS RESTRAINTS\. RMS SIGMA/WEIGHT)", 1 },
-	/* 77 */ { R"(GROUP (\d+) POSITIONAL \(A\)\s*:\s*(.+))", 1, /* "refine_ls_restr_ncs", { "dom_id", "rms_dev_position", "weight_position" } */ },
-	/* 78 */ { R"(GROUP (\d+) B-FACTOR \(A\*\*2\)\s*:\s*(.+))", 1, /* "refine_ls_restr_ncs", { "dom_id", "rms_dev_B_iso", "weight_B_iso" } */ },
-	/* 79 */ { R"(PARAMETER FILE (\d+) :\s+(.+))", 1, /* "pdbx_xplor_file", { "serial_no", "param_file" } */ },
-	/* 80 */ { R"(TOPOLOGY FILE (\d+) :\s+(.+))", 1, /* "pdbx_xplor_file", { "serial_no", "topol_file" } */ },
+	/* 77 */ { R"(GROUP (\d+) POSITIONAL \(A\)\s*:\s*(.+))",
+		1,
+		/* "refine_ls_restr_ncs", { "dom_id", "rms_dev_position", "weight_position" } */ },
+	/* 78 */ { R"(GROUP (\d+) B-FACTOR \(A\*\*2\)\s*:\s*(.+))",
+		1,
+		/* "refine_ls_restr_ncs", { "dom_id", "rms_dev_B_iso", "weight_B_iso" } */ },
+	/* 79 */ { R"(PARAMETER FILE (\d+) :\s+(.+))",
+		1,
+		/* "pdbx_xplor_file", { "serial_no", "param_file" } */ },
+	/* 80 */ { R"(TOPOLOGY FILE (\d+) :\s+(.+))",
+		1,
+		/* "pdbx_xplor_file", { "serial_no", "topol_file" } */ },
 };
 
 class CNS_Remark3Parser : public Remark3Parser
 {
   public:
-	CNS_Remark3Parser(const std::string &name, const std::string &expMethod, PDBRecord *r, cif::datablock &db)
+	CNS_Remark3Parser(std::string name, std::string expMethod, PDBRecord *r, cif::datablock &db)
 		: Remark3Parser(name, expMethod, r, db, kCNS_Template,
 			  sizeof(kCNS_Template) / sizeof(TemplateLine), std::regex(R"((CN[SX])(?: (\d+(?:\.\d+)?))?)"))
 	{
@@ -332,13 +351,13 @@ const TemplateLine kPHENIX_Template[] = {
 class PHENIX_Remark3Parser : public Remark3Parser
 {
   public:
-	PHENIX_Remark3Parser(const std::string &name, const std::string &expMethod, PDBRecord *r, cif::datablock &db)
+	PHENIX_Remark3Parser(std::string name, std::string expMethod, PDBRecord *r, cif::datablock &db)
 		: Remark3Parser(name, expMethod, r, db, kPHENIX_Template, sizeof(kPHENIX_Template) / sizeof(TemplateLine),
 			  std::regex(R"((PHENIX)(?: \(PHENIX\.REFINE:) (\d+(?:\.[^)]+)?)\)?)"))
 	{
 	}
 
-	virtual void fixup();
+	void fixup() override;
 };
 
 void PHENIX_Remark3Parser::fixup()
@@ -347,7 +366,7 @@ void PHENIX_Remark3Parser::fixup()
 	{
 		try
 		{
-			float val = r["percent_reflns_obs"].as<float>();
+			auto val = r["percent_reflns_obs"].get<float>();
 			int perc = static_cast<int>(val * 100);
 			r["percent_reflns_obs"] = perc;
 		}
@@ -420,13 +439,13 @@ const TemplateLine kNUCLSQ_Template[] = {
 class NUCLSQ_Remark3Parser : public Remark3Parser
 {
   public:
-	NUCLSQ_Remark3Parser(const std::string &name, const std::string &expMethod, PDBRecord *r, cif::datablock &db)
+	NUCLSQ_Remark3Parser(std::string name, std::string expMethod, PDBRecord *r, cif::datablock &db)
 		: Remark3Parser(name, expMethod, r, db, kNUCLSQ_Template, sizeof(kNUCLSQ_Template) / sizeof(TemplateLine),
 			  std::regex(R"((NUCLSQ)(?: (\d+(?:\.\d+)?))?)"))
 	{
 	}
 
-	virtual void fixup()
+	void fixup() override
 	{
 		for (auto r : mDb["refine_hist"])
 		{
@@ -513,13 +532,13 @@ const TemplateLine kPROLSQ_Template[] = {
 class PROLSQ_Remark3Parser : public Remark3Parser
 {
   public:
-	PROLSQ_Remark3Parser(const std::string &name, const std::string &expMethod, PDBRecord *r, cif::datablock &db)
+	PROLSQ_Remark3Parser(std::string name, std::string expMethod, PDBRecord *r, cif::datablock &db)
 		: Remark3Parser(name, expMethod, r, db, kPROLSQ_Template, sizeof(kPROLSQ_Template) / sizeof(TemplateLine),
 			  std::regex(R"((PROLSQ)(?: (\d+(?:\.\d+)?))?)"))
 	{
 	}
 
-	virtual void fixup()
+	void fixup() override
 	{
 		for (auto r : mDb["refine_hist"])
 		{
@@ -556,7 +575,9 @@ const TemplateLine kREFMAC_Template[] = {
 	/* 17 */ { R"(NUCLEIC ACID ATOMS\s*:\s*(.+))", 1, "refine_hist", { "pdbx_number_atoms_nucleic_acid" } },
 	/* 18 */ { R"(HETEROGEN ATOMS\s*:\s*(.+))", 1, "refine_hist", { "pdbx_number_atoms_ligand" } },
 	/* 19 */ { R"(SOLVENT ATOMS\s*:\s*(.+))", 1, "refine_hist", { "number_atoms_solvent" } },
-	/* 20 */ { R"(ALL ATOMS\s*:\s*(.+))", 1, /* "refine_hist", "pdbx_number_atoms_protein" */ },
+	/* 20 */ { R"(ALL ATOMS\s*:\s*(.+))",
+		1,
+		/* "refine_hist", "pdbx_number_atoms_protein" */ },
 	/* 21 */ { R"(B VALUES\..*)", 1 },
 	/* 22 */ { R"(B VALUE TYPE\s*:\s*(.+))", 1, "refine", { "pdbx_TLS_residual_ADP_flag" } },
 	/* 23 */ { R"(FROM WILSON PLOT \(A\*\*2\)\s*:\s*(.+))", 1, "reflns", { "B_iso_Wilson_estimate" } },
@@ -601,14 +622,14 @@ const TemplateLine kREFMAC_Template[] = {
 class REFMAC_Remark3Parser : public Remark3Parser
 {
   public:
-	REFMAC_Remark3Parser(const std::string &name, const std::string &expMethod, PDBRecord *r, cif::datablock &db)
+	REFMAC_Remark3Parser(std::string name, std::string expMethod, PDBRecord *r, cif::datablock &db)
 		: Remark3Parser(name, expMethod, r, db, kREFMAC_Template, sizeof(kREFMAC_Template) / sizeof(TemplateLine),
 			  std::regex(".+"))
 	{
 	}
 
-	virtual std::string program() { return "REFMAC"; }
-	virtual std::string version() { return ""; }
+	std::string program() override { return "REFMAC"; }
+	std::string version() override { return ""; }
 };
 
 const TemplateLine kREFMAC5_Template[] = {
@@ -641,7 +662,9 @@ const TemplateLine kREFMAC5_Template[] = {
 	/* 26 */ { R"(NUCLEIC ACID ATOMS\s*:\s*(.+))", 1, "refine_hist", { "pdbx_number_atoms_nucleic_acid" } },
 	/* 27 */ { R"(HETEROGEN ATOMS\s*:\s*(.+))", 1, "refine_hist", { "pdbx_number_atoms_ligand" } },
 	/* 28 */ { R"(SOLVENT ATOMS\s*:\s*(.+))", 1, "refine_hist", { "number_atoms_solvent" } },
-	/* 29 */ { R"(ALL ATOMS\s*:\s*(.+))", 1, /* "refine_hist", { "pdbx_number_atoms_protein" } */ },
+	/* 29 */ { R"(ALL ATOMS\s*:\s*(.+))",
+		1,
+		/* "refine_hist", { "pdbx_number_atoms_protein" } */ },
 	/* 30 */ { R"(B VALUES\..*)", 1 },
 	/* 31 */ { R"(B VALUE TYPE\s*:\s*(.+))", 1, "refine", { "pdbx_TLS_residual_ADP_flag" } },
 	/* 32 */ { R"(FROM WILSON PLOT \(A\*\*2\)\s*:\s*(.+))", 1, "reflns", { "B_iso_Wilson_estimate" } },
@@ -705,8 +728,12 @@ const TemplateLine kREFMAC5_Template[] = {
 	//	Simply ignore NCS, you can ask Robbie why
 	/* 90 */ { R"(NCS RESTRAINTS STATISTICS)", 1 },
 	/* 91 */ { R"(NUMBER OF DIFFERENT NCS GROUPS\s*:\s*(.+))", 1 },
-	/* 92 */ { R"(NCS GROUP NUMBER\s*:\s*(\d+))", 1, /*"struct_ncs_dom", { "pdbx_ens_id" }*/ },
-	/* 93 */ { R"(CHAIN NAMES\s*:\s*(.+))", 1, /*"struct_ncs_dom", { "details" }*/ },
+	/* 92 */ { R"(NCS GROUP NUMBER\s*:\s*(\d+))",
+		1,
+		/*"struct_ncs_dom", { "pdbx_ens_id" }*/ },
+	/* 93 */ { R"(CHAIN NAMES\s*:\s*(.+))",
+		1,
+		/*"struct_ncs_dom", { "details" }*/ },
 	/* 94 */ { R"(NUMBER OF COMPONENTS NCS GROUP\s*:\s*(\d+))", 1 },
 	/* 95 */ { R"(COMPONENT C SSSEQI TO C SSSEQI CODE)", 1 },
 	//// This sucks.... The following line is fixed format
@@ -719,7 +746,9 @@ const TemplateLine kREFMAC5_Template[] = {
 	/* 102 */ { R"(TIGHT THERMAL\s+\d+\s+(.)\s+\(A\*\*2\):\s+(\d+)\s*;\s*(\d+(?:\.\d*)?)\s*;\s*(\d+(?:\.\d*)?))", 0 },  // , "refine_ls_restr_ncs", {"pdbx_auth_asym_id", "pdbx_number", "rms_dev_position", "weight_position"}, { "pdbx_type", "tight thermal", }, 1 },
 	/* 103 */ { R"(MEDIUM THERMAL\s+\d+\s+(.)\s+\(A\*\*2\):\s+(\d+)\s*;\s*(\d+(?:\.\d*)?)\s*;\s*(\d+(?:\.\d*)?))", 0 }, // , "refine_ls_restr_ncs", {"pdbx_auth_asym_id", "pdbx_number", "rms_dev_position", "weight_position"}, { "pdbx_type", "medium thermal", }, 1 },
 	/* 104 */ { R"(LOOSE THERMAL\s+\d+\s+(.)\s+\(A\*\*2\):\s+(\d+)\s*;\s*(\d+(?:\.\d*)?)\s*;\s*(\d+(?:\.\d*)?))", 0 },  // , "refine_ls_restr_ncs", {"pdbx_auth_asym_id", "pdbx_number", "rms_dev_position", "weight_position"}, { "pdbx_type", "loose thermal", }, 10 },
-	/* 105 */ { R"(NCS GROUP NUMBER\s*:\s*(\d+))", 93 - 105, /*"struct_ncs_dom", { "pdbx_ens_id" }*/ },
+	/* 105 */ { R"(NCS GROUP NUMBER\s*:\s*(\d+))",
+		93 - 105,
+		/*"struct_ncs_dom", { "pdbx_ens_id" }*/ },
 	/* 106 */ { R"(TWIN DETAILS)", 1 },
 	/* 107 */ { R"(NUMBER OF TWIN DOMAINS\s*:\s*(\d*))", 1 },
 	/* 108 */ { R"(TWIN DOMAIN\s*:\s*(.+))", 1, "pdbx_reflns_twin", { "domain_id" }, nullptr, true },
@@ -755,7 +784,7 @@ const TemplateLine kREFMAC5_Template[] = {
 class REFMAC5_Remark3Parser : public Remark3Parser
 {
   public:
-	REFMAC5_Remark3Parser(const std::string &name, const std::string &expMethod, PDBRecord *r, cif::datablock &db)
+	REFMAC5_Remark3Parser(std::string name, std::string expMethod, PDBRecord *r, cif::datablock &db)
 		: Remark3Parser(name, expMethod, r, db, kREFMAC5_Template, sizeof(kREFMAC5_Template) / sizeof(TemplateLine),
 			  std::regex(R"((REFMAC)(?: (\d+(?:\..+)?))?)"))
 	{
@@ -815,7 +844,7 @@ const TemplateLine kSHELXL_Template[] = {
 class SHELXL_Remark3Parser : public Remark3Parser
 {
   public:
-	SHELXL_Remark3Parser(const std::string &name, const std::string &expMethod, PDBRecord *r, cif::datablock &db)
+	SHELXL_Remark3Parser(std::string name, std::string expMethod, PDBRecord *r, cif::datablock &db)
 		: Remark3Parser(name, expMethod, r, db, kSHELXL_Template, sizeof(kSHELXL_Template) / sizeof(TemplateLine),
 			  std::regex(R"((SHELXL)(?:-(\d+(?:\..+)?)))"))
 	{
@@ -872,7 +901,7 @@ const TemplateLine kTNT_Template[] = {
 class TNT_Remark3Parser : public Remark3Parser
 {
   public:
-	TNT_Remark3Parser(const std::string &name, const std::string &expMethod, PDBRecord *r, cif::datablock &db)
+	TNT_Remark3Parser(std::string name, std::string expMethod, PDBRecord *r, cif::datablock &db)
 		: Remark3Parser(name, expMethod, r, db, kTNT_Template, sizeof(kTNT_Template) / sizeof(TemplateLine),
 			  std::regex(R"((TNT)(?: V. (\d+.+)?)?)"))
 	{
@@ -941,18 +970,28 @@ const TemplateLine kXPLOR_Template[] = {
 	/* 58 */ { R"(MAIN-CHAIN ANGLE \(A\*\*2\) :\s+(.+?);\s+(.+))", 1, "refine_ls_restr", { "dev_ideal", "dev_ideal_target" }, "x_mcangle_it", false },
 	/* 59 */ { R"(SIDE-CHAIN BOND \(A\*\*2\) :\s+(.+?);\s+(.+))", 1, "refine_ls_restr", { "dev_ideal", "dev_ideal_target" }, "x_scbond_it", false },
 	/* 60 */ { R"(SIDE-CHAIN ANGLE \(A\*\*2\) :\s+(.+?);\s+(.+))", 1, "refine_ls_restr", { "dev_ideal", "dev_ideal_target" }, "x_scangle_it", false },
-	/* 61 */ { R"(NCS MODEL :\s+(.+))", 1, /* "refine_ls_restr_ncs", { "ncs_model_details" } */ },
+	/* 61 */ { R"(NCS MODEL :\s+(.+))",
+		1,
+		/* "refine_ls_restr_ncs", { "ncs_model_details" } */ },
 	/* 62 */ { R"(NCS RESTRAINTS\. RMS SIGMA/WEIGHT)", 1 },
-	/* 63 */ { R"(GROUP (\d+) POSITIONAL \(A\) :\s+(.+?);\s+(.+))", 1, /* "refine_ls_restr_ncs", { ":dom_id", "rms_dev_position", "weight_position" } */ },
-	/* 64 */ { R"(GROUP (\d+) B-FACTOR \(A\*\*2\) :\s+(.+?);\s+(.+))", 63 - 64, /* "refine_ls_restr_ncs", { ":dom_id", "rms_dev_B_iso", "weight_B_iso" } */ },
-	/* 65 */ { R"(PARAMETER FILE (\d+) :\s+(.+))", 0, /* "pdbx_xplor_file", { "serial_no", "param_file" } */ },
-	/* 66 */ { R"(TOPOLOGY FILE (\d+) :\s+(.+))", 0, /* "pdbx_xplor_file", { "serial_no", "topol_file" } */ },
+	/* 63 */ { R"(GROUP (\d+) POSITIONAL \(A\) :\s+(.+?);\s+(.+))",
+		1,
+		/* "refine_ls_restr_ncs", { ":dom_id", "rms_dev_position", "weight_position" } */ },
+	/* 64 */ { R"(GROUP (\d+) B-FACTOR \(A\*\*2\) :\s+(.+?);\s+(.+))",
+		63 - 64,
+		/* "refine_ls_restr_ncs", { ":dom_id", "rms_dev_B_iso", "weight_B_iso" } */ },
+	/* 65 */ { R"(PARAMETER FILE (\d+) :\s+(.+))",
+		0,
+		/* "pdbx_xplor_file", { "serial_no", "param_file" } */ },
+	/* 66 */ { R"(TOPOLOGY FILE (\d+) :\s+(.+))",
+		0,
+		/* "pdbx_xplor_file", { "serial_no", "topol_file" } */ },
 };
 
 class XPLOR_Remark3Parser : public Remark3Parser
 {
   public:
-	XPLOR_Remark3Parser(const std::string &name, const std::string &expMethod, PDBRecord *r, cif::datablock &db)
+	XPLOR_Remark3Parser(std::string name, std::string expMethod, PDBRecord *r, cif::datablock &db)
 		: Remark3Parser(name, expMethod, r, db, kXPLOR_Template, sizeof(kXPLOR_Template) / sizeof(TemplateLine),
 			  std::regex(R"((X-PLOR)(?: (\d+(?:\.\d+)?))?)"))
 	{
@@ -961,15 +1000,15 @@ class XPLOR_Remark3Parser : public Remark3Parser
 
 // --------------------------------------------------------------------
 
-Remark3Parser::Remark3Parser(const std::string &name, const std::string &expMethod, PDBRecord *r, cif::datablock &db,
+Remark3Parser::Remark3Parser(std::string name, std::string expMethod, PDBRecord *r, cif::datablock &db,
 	const TemplateLine templatelines[], uint32_t templateLineCount, std::regex programversion)
-	: mName(name)
-	, mExpMethod(expMethod)
+	: mName(std::move(name))
+	, mExpMethod(std::move(expMethod))
 	, mRec(r)
 	, mDb(db.name())
 	, mTemplate(templatelines)
 	, mTemplateCount(templateLineCount)
-	, mProgramVersion(programversion)
+	, mProgramVersion(std::move(programversion))
 {
 	mDb.set_validator(db.get_validator());
 }
@@ -1042,13 +1081,13 @@ std::string Remark3Parser::nextLine()
 		break;
 	}
 
-	if (cif::VERBOSE >= 2)
+	if (VERBOSE >= 2)
 		std::cerr << "RM3: " << mLine << '\n';
 
 	return mLine;
 }
 
-bool Remark3Parser::match(const char *expr, int nextState)
+bool Remark3Parser::match(const char *expr, uint32_t nextState)
 {
 	std::regex rx(expr);
 
@@ -1056,7 +1095,7 @@ bool Remark3Parser::match(const char *expr, int nextState)
 
 	if (result)
 		mState = nextState;
-	else if (cif::VERBOSE >= 3)
+	else if (VERBOSE >= 3)
 	{
 		using namespace colour;
 
@@ -1085,7 +1124,7 @@ float Remark3Parser::parse()
 		if (mState == 0 and match(R"(AUTHORS\s*:.+)", 0))
 			continue;
 
-		auto state = mState;
+		uint32_t state;
 		for (state = mState; state < mTemplateCount; ++state)
 		{
 			const TemplateLine &tmpl = mTemplate[state];
@@ -1120,7 +1159,7 @@ float Remark3Parser::parse()
 			continue;
 		}
 
-		if (cif::VERBOSE >= 2)
+		if (VERBOSE >= 2)
 		{
 			using namespace colour;
 
@@ -1136,7 +1175,7 @@ float Remark3Parser::parse()
 			mDb["refine"].front()["details"] = remarks;
 	}
 
-	float score = float(lineCount - dropped) / lineCount;
+	float score = static_cast<float>(lineCount - dropped) / static_cast<float>(lineCount);
 
 	return score;
 }
@@ -1176,7 +1215,7 @@ void Remark3Parser::storeCapture(const char *category, std::initializer_list<con
 		if (iequals(value, "NULL") or iequals(value, "NONE") or iequals(value, "Inf") or iequals(value, "+Inf") or iequals(value, std::string(value.length(), '*')))
 			continue;
 
-		if (cif::VERBOSE >= 3)
+		if (VERBOSE >= 3)
 			std::cerr << "storing: '" << value << "' in _" << category << '.' << item << '\n';
 
 		auto &cat = mDb[category];
@@ -1185,7 +1224,7 @@ void Remark3Parser::storeCapture(const char *category, std::initializer_list<con
 			if (iequals(category, "refine"))
 				cat.emplace({ { "pdbx_refine_id", mExpMethod },
 					{ "entry_id", mDb.name() },
-					//#warning("this diffrn-id is probably not correct?")
+					// #warning("this diffrn-id is probably not correct?")
 					{ "pdbx_diffrn_id", 1 } });
 			else if (iequals(category, "refine_analyze") or iequals(category, "pdbx_refine"))
 				cat.emplace({
@@ -1195,17 +1234,17 @@ void Remark3Parser::storeCapture(const char *category, std::initializer_list<con
 				});
 			else if (iequals(category, "refine_hist"))
 			{
-				std::string dResHigh, dResLow;
+				std::optional<float> dResHigh, dResLow;
 				for (auto r : mDb["refine"])
 				{
-					cif::tie(dResHigh, dResLow) = r.get("ls_d_res_high", "ls_d_res_low");
+					cif::tie(dResHigh, dResLow) = r.get<float, float>("ls_d_res_high", "ls_d_res_low");
 					break;
 				}
 
 				cat.emplace({ { "pdbx_refine_id", mExpMethod },
 					{ "cycle_id", "LAST" },
-					{ "d_res_high", dResHigh.empty() ? "." : dResHigh },
-					{ "d_res_low", dResLow.empty() ? "." : dResLow } });
+					{ "d_res_high", dResHigh },
+					{ "d_res_low", dResLow } });
 			}
 			else if (iequals(category, "refine_ls_shell"))
 			{
@@ -1217,11 +1256,10 @@ void Remark3Parser::storeCapture(const char *category, std::initializer_list<con
 			{
 				std::string tlsID;
 				if (not mDb["pdbx_refine_tls"].empty())
-					tlsID = mDb["pdbx_refine_tls"].back()["id"].as<std::string>();
+					tlsID = mDb["pdbx_refine_tls"].back()["id"].get<std::string>();
 				std::string tlsGroupID = cat.get_unique_id("");
 
-				cat.emplace({
-					{ "pdbx_refine_id", mExpMethod },
+				cat.emplace({ { "pdbx_refine_id", mExpMethod },
 					{ "id", tlsGroupID },
 					{ "refine_tls_id", tlsID } });
 			}
@@ -1276,10 +1314,8 @@ void Remark3Parser::storeRefineLsRestr(const char *type, std::initializer_list<c
 
 		if (r.empty())
 		{
-			r = mDb["refine_ls_restr"].emplace({
-				{"pdbx_refine_id", mExpMethod},
-				{"type", type}
-			});
+			r = mDb["refine_ls_restr"].emplace({ { "pdbx_refine_id", mExpMethod },
+				{ "type", type } });
 		}
 
 		r[item] = value;
@@ -1337,7 +1373,7 @@ bool Remark3Parser::parse(const std::string &expMethod, PDBRecord *r, cif::datab
 
 	if (line != "REFINEMENT.")
 	{
-		if (cif::VERBOSE > 0)
+		if (VERBOSE > 0)
 			std::cerr << "Unexpected data in REMARK 3\n";
 		return false;
 	}
@@ -1349,7 +1385,7 @@ bool Remark3Parser::parse(const std::string &expMethod, PDBRecord *r, cif::datab
 
 	if (not std::regex_match(line, m, rxp))
 	{
-		if (cif::VERBOSE > 0)
+		if (VERBOSE > 0)
 			std::cerr << "Expected valid PROGRAM line in REMARK 3\n";
 		return false;
 	}
@@ -1358,8 +1394,8 @@ bool Remark3Parser::parse(const std::string &expMethod, PDBRecord *r, cif::datab
 
 	struct programScore
 	{
-		programScore(const std::string &program, Remark3Parser *parser, float score)
-			: program(program)
+		programScore(std::string program, Remark3Parser *parser, float score)
+			: program(std::move(program))
 			, parser(parser)
 			, score(score)
 		{
@@ -1388,20 +1424,18 @@ bool Remark3Parser::parse(const std::string &expMethod, PDBRecord *r, cif::datab
 		}
 		catch (const std::exception &e)
 		{
-			if (cif::VERBOSE >= 0)
+			if (VERBOSE >= 0)
 				std::cerr << "Error parsing REMARK 3 with " << parser->program() << '\n'
 						  << e.what() << '\n';
 			score = 0;
 		}
 
-		if (cif::VERBOSE >= 2)
+		if (VERBOSE >= 2)
 			std::cerr << "Score for " << parser->program() << ": " << score << '\n';
 
 		if (score > 0)
 		{
 			std::string program = parser->program();
-			std::string version = parser->version();
-
 			scores.emplace_back(program, parser.release(), score);
 		}
 	};
@@ -1430,16 +1464,16 @@ bool Remark3Parser::parse(const std::string &expMethod, PDBRecord *r, cif::datab
 			tryParser(new TNT_Remark3Parser(program, expMethod, r, db));
 		else if (cif::starts_with(program, "X-PLOR"))
 			tryParser(new XPLOR_Remark3Parser(program, expMethod, r, db));
-		else if (cif::VERBOSE > 0)
+		else if (VERBOSE > 0)
 			std::cerr << "Skipping unknown program (" << program << ") in REMARK 3\n";
 	}
 
-	sort(scores.begin(), scores.end());
+	std::sort(scores.begin(), scores.end()); // NOLINT(modernize-use-ranges)
 
 	bool guessProgram = scores.empty() or scores.front().score < 0.9f;
 	if (guessProgram)
 	{
-		if (cif::VERBOSE > 0)
+		if (VERBOSE > 0)
 			std::cerr << "Unknown or untrusted program in REMARK 3, trying all parsers to see if there is a match\n";
 
 		tryParser(new BUSTER_TNT_Remark3Parser("BUSTER-TNT", expMethod, r, db));
@@ -1460,11 +1494,11 @@ bool Remark3Parser::parse(const std::string &expMethod, PDBRecord *r, cif::datab
 	{
 		result = true;
 
-		sort(scores.begin(), scores.end());
+		sort(scores.begin(), scores.end()); // NOLINT(modernize-use-ranges)
 
 		auto &best = scores.front();
 
-		if (cif::VERBOSE > 0)
+		if (VERBOSE > 0)
 			std::cerr << "Choosing " << best.parser->program() << " version '" << best.parser->version() << "' as refinement program. Score = " << best.score << '\n';
 
 		auto &software = db["software"];
@@ -1478,7 +1512,7 @@ bool Remark3Parser::parse(const std::string &expMethod, PDBRecord *r, cif::datab
 
 		best.parser->fixup();
 
-		auto &validator = cif::validator_factory::instance().get("mmcif_pdbx.dic");
+		auto &validator = cif::validator_factory::instance()["mmcif_pdbx.dic"];
 
 		for (auto &cat1 : best.parser->mDb)
 		{
@@ -1487,37 +1521,104 @@ bool Remark3Parser::parse(const std::string &expMethod, PDBRecord *r, cif::datab
 
 			auto &cat2 = db[cat1.name()];
 
-			// copy only the values in the first row for the following categories
-			if (cat1.name() == "reflns" or cat1.name() == "refine")
-			{
-				if (cat2.empty())
-					cat2.emplace(cat1.front());
-				else
-				{
-						
-					auto r1 = cat1.front();
-					auto r2 = cat2.front();
+			row_handle r1 = cat1.front();
+			row_handle r2;
 
-					auto cv = cat1.get_cat_validator();
-					if (cv == nullptr)
-						cv = validator.get_validator_for_category(cat1.name());
-					
-					if (cv == nullptr)
-						continue;
-
-					for (auto &iv : cv->m_item_validators)
-						r2[iv.m_item_name] = r1[iv.m_item_name].text();
-				}
-			}
+			if (cat2.empty() or (cat1.name() == "reflns" or cat1.name() == "refine"))
+				r2 = cat2.emplace({});
 			else
+				r2 = cat2.front();
+
+			auto cv = cat1.get_cat_validator();
+			if (cv == nullptr)
+				cv = validator.get_validator_for_category(cat1.name());
+
+			if (cv == nullptr)
+				continue;
+
+			for (auto &iv : cv->m_item_validators)
 			{
-				for (auto rs : cat1)
-					cat2.emplace(rs);
+				if (r1[iv.m_item_name].empty())
+					continue;
+
+				// if (iv.m_type and iv.m_type->m_primitive_type == DDL_PrimitiveType::Numb)
+				// {
+				// 	try
+				// 	{
+				// 		r2[iv.m_item_name] = r1[iv.m_item_name].get<int64_t>();
+				// 		continue;
+				// 	}
+				// 	catch (...)
+				// 	{
+				// 	}
+
+				// 	try
+				// 	{
+				// 		r2[iv.m_item_name] = r1[iv.m_item_name].get<double>();
+				// 		continue;
+				// 	}
+				// 	catch (...)
+				// 	{
+				// 	}
+				// }
+
+				r2[iv.m_item_name] = r1[iv.m_item_name].value();
 			}
+
+			// // copy only the values in the first row for the following categories
+			// if (cat1.name() == "reflns" or cat1.name() == "refine")
+			// {
+			// 	if (cat2.empty())
+			// 		cat2.emplace(cat1.front());
+			// 	else
+			// 	{
+			// 		auto r1 = cat1.front();
+			// 		auto r2 = cat2.front();
+
+			// 		auto cv = cat1.get_cat_validator();
+			// 		if (cv == nullptr)
+			// 			cv = validator.get_validator_for_category(cat1.name());
+
+			// 		if (cv == nullptr)
+			// 			continue;
+
+			// 		for (auto &iv : cv->m_item_validators)
+			// 		{
+			// 			if (r1[iv.m_item_name].empty())
+			// 				continue;
+
+			// 			if (iv.m_type and iv.m_type->m_primitive_type == DDL_PrimitiveType::Numb)
+			// 			{
+			// 				try
+			// 				{
+			// 					r2[iv.m_item_name] = r1[iv.m_item_name].get<int64_t>();
+			// 					continue;
+			// 				}
+			// 				catch (...) {}
+
+			// 				try
+			// 				{
+			// 					r2[iv.m_item_name] = r1[iv.m_item_name].get<double>();
+			// 					continue;
+			// 				}
+			// 				catch (...) {}
+			// 			}
+
+			// 			r2[iv.m_item_name] = r1[iv.m_item_name].value();
+			// 		}
+			// 	}
+			// }
+			// else
+			// {
+			// 	for (auto rs : cat1)
+			// 		cat2.emplace(rs);
+			// }
 		}
 	}
 
 	return result;
 }
 
-} // namespace pdbx
+} // namespace cif::pdb
+
+// NOLINTEND(bugprone-empty-catch)

src/pdb/pdb2cif_remark_3.hpp

@@ -26,8 +26,14 @@
 
 #pragma once
 
+#include "cif++/datablock.hpp"
 #include "pdb_record.hpp"
 
+#include <cstdint>
+#include <initializer_list>
+#include <regex>
+#include <string>
+
 // --------------------------------------------------------------------
 
 namespace cif::pdb
@@ -38,7 +44,7 @@ struct TemplateLine;
 class Remark3Parser
 {
   public:
-	virtual ~Remark3Parser() {}
+	virtual ~Remark3Parser() = default;
 
 	static bool parse(const std::string &expMethod, PDBRecord *r, cif::datablock &db);
 
@@ -46,13 +52,13 @@ class Remark3Parser
 	virtual std::string version();
 
   protected:
-	Remark3Parser(const std::string &name, const std::string &expMethod, PDBRecord *r, cif::datablock &db,
+	Remark3Parser(std::string name, std::string expMethod, PDBRecord *r, cif::datablock &db,
 		const TemplateLine templatelines[], uint32_t templateLineCount, std::regex programVersion);
 
 	virtual float parse();
 	std::string nextLine();
 
-	bool match(const char *expr, int nextState);
+	bool match(const char *expr, uint32_t nextState);
 	void storeCapture(const char *category, std::initializer_list<const char *> items, bool createNew = false);
 	void storeRefineLsRestr(const char *type, std::initializer_list<const char *> values);
 	void updateRefineLsRestr(const char *type, std::initializer_list<const char *> values);
@@ -72,4 +78,4 @@ class Remark3Parser
 	std::regex mProgramVersion;
 };
 
-} // namespace pdbx
+} // namespace cif::pdb

src/pdb/pdb_record.hpp

@@ -26,7 +26,10 @@
 
 #pragma once
 
-#include "cif++/file.hpp"
+#include <cstdint>
+#include <limits>
+#include <optional>
+#include <string>
 
 /// \file pdb_record.hpp
 
@@ -37,14 +40,14 @@ namespace cif::pdb
 
 struct PDBRecord
 {
-	PDBRecord *mNext;
+	PDBRecord *mNext = nullptr;
 	uint32_t mLineNr;
 	char mName[11];
 	std::size_t mVlen;
 	char mValue[1];
 
 	PDBRecord(uint32_t lineNr, const std::string &name, const std::string &value);
-	~PDBRecord();
+	~PDBRecord() = default;
 
 	void *operator new(std::size_t);
 	void *operator new(std::size_t size, std::size_t vLen);
@@ -57,7 +60,7 @@ struct PDBRecord
 	char vC(std::size_t column);
 	std::string vS(std::size_t columnFirst, std::size_t columnLast = std::numeric_limits<std::size_t>::max());
 	int vI(int columnFirst, int columnLast);
-	std::string vF(std::size_t columnFirst, std::size_t columnLast);
+	std::optional<float> vF(std::size_t columnFirst, std::size_t columnLast);
 };
 
-} // namespace pdbx
+} // namespace cif::pdb

src/pdb/validate-pdbx.cpp

@@ -24,12 +24,27 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "cif++.hpp"
+#include "cif++/cif++.hpp"
+
+#include <algorithm>
+#include <cctype>
+#include <cstddef>
+#include <exception>
+#include <iostream>
+#include <map>
+#include <optional>
+#include <set>
+#include <stdexcept>
+#include <string>
+#include <system_error>
+#include <tuple>
+#include <utility>
+#include <vector>
 
 namespace cif::pdb
 {
 
-condition get_parents_condition(const validator &validator, row_handle rh, const category &parentCat)
+condition get_parents_condition(const validator &validator, const_row_handle rh, const category &parentCat)
 {
 	condition result;
 
@@ -38,9 +53,8 @@ condition get_parents_condition(const validator &validator, row_handle rh, const
 	auto parentName = parentCat.name();
 
 	auto links = validator.get_links_for_child(childName);
-	links.erase(remove_if(links.begin(), links.end(), [n = parentName](auto &l)
-					{ return l->m_parent_category != n; }),
-		links.end());
+	std::erase_if(links, [n = parentName](auto &l)
+		{ return l->m_parent_category != n; });
 
 	if (not links.empty())
 	{
@@ -50,12 +64,10 @@ condition get_parents_condition(const validator &validator, row_handle rh, const
 
 			for (std::size_t ix = 0; ix < link->m_child_keys.size(); ++ix)
 			{
-				auto childValue = rh[link->m_child_keys[ix]];
-
-				if (childValue.empty())
+				if (rh[link->m_child_keys[ix]].empty())
 					continue;
 
-				cond = std::move(cond) and key(link->m_parent_keys[ix]) == childValue.text();
+				cond = std::move(cond) and key(link->m_parent_keys[ix]) == rh[link->m_child_keys[ix]].value();
 			}
 
 			result = std::move(result) or std::move(cond);
@@ -65,11 +77,18 @@ condition get_parents_condition(const validator &validator, row_handle rh, const
 	return result;
 }
 
+bool is_valid_pdbx_file(const file &file)
+{
+	std::error_code ec;
+	bool result = is_valid_pdbx_file(file, validator_factory::instance()["mmcif_pdbx.dic"], ec);
+	return result and ec == std::errc{};
+}
+
 bool is_valid_pdbx_file(const file &file, const validator &v)
 {
 	std::error_code ec;
 	bool result = is_valid_pdbx_file(file, v, ec);
-	return result and not (bool)ec;
+	return result and ec == std::errc{};
 }
 
 bool is_valid_pdbx_file(const file &file, std::error_code &ec)
@@ -79,10 +98,10 @@ bool is_valid_pdbx_file(const file &file, std::error_code &ec)
 	if (file.empty())
 		ec = make_error_code(validation_error::empty_file);
 	else if (auto ac = file.front().get("audit_conform"); ac != nullptr)
-		result = is_valid_pdbx_file(file, validator_factory::instance().get(*ac), ec);
+		result = is_valid_pdbx_file(file, validator_factory::instance()[*ac], ec);
 	else
-		result = is_valid_pdbx_file(file, validator_factory::instance().get("mmcif_pdbx.dic"), ec);
-	
+		result = is_valid_pdbx_file(file, validator_factory::instance()["mmcif_pdbx.dic"], ec);
+
 	return result;
 }
 
@@ -110,7 +129,6 @@ bool is_valid_pdbx_file(const file &file, const validator &validator, std::error
 
 		auto &pdbx_poly_seq_scheme = db["pdbx_poly_seq_scheme"];
 
-		std::string last_asym_id;
 		int last_seq_id = -1;
 		for (auto r : atom_site)
 		{
@@ -139,7 +157,7 @@ bool is_valid_pdbx_file(const file &file, const validator &validator, std::error
 			if (p.size() != 1)
 			{
 				if (VERBOSE > 0)
-					std::clog << "In atom_site record: " << r["id"].text() << '\n';
+					std::clog << "In atom_site record: " << r["id"].str() << '\n';
 				throw std::runtime_error("For each monomer in atom_site there should be exactly one pdbx_poly_seq_scheme record");
 			}
 		}
@@ -165,11 +183,11 @@ bool is_valid_pdbx_file(const file &file, const validator &validator, std::error
 			if (entity_poly.count("entity_id"_key == entity_id) != 1)
 				throw std::runtime_error("There should be exactly one entity_poly record per polymer entity");
 
-			const auto entity_poly_type = entity_poly.find1<std::string>("entity_id"_key == entity_id, "type");
+			// const auto entity_poly_type = entity_poly.find1<std::string>("entity_id"_key == entity_id, "type");
 
-			std::map<int,std::set<std::string>> mon_per_seq_id;
+			std::map<int, std::set<std::string>> mon_per_seq_id;
 
-			for (const auto &[num, mon_id, hetero] : entity_poly_seq.find<int, std::string, bool>("entity_id"_key == entity_id, "num", "mon_id", "hetero"))
+			for (const auto &[num, mon_id, hetero] : entity_poly_seq.find<int, std::string, std::string>("entity_id"_key == entity_id, "num", "mon_id", "hetero"))
 			{
 				mon_per_seq_id[num].emplace(mon_id);
 
@@ -187,7 +205,7 @@ bool is_valid_pdbx_file(const file &file, const validator &validator, std::error
 				}
 			}
 
-			for (const auto &[seq_id, mon_id, hetero] : pdbx_poly_seq_scheme.find<int, std::string, bool>("entity_id"_key == entity_id, "seq_id", "mon_id", "hetero"))
+			for (const auto &[seq_id, mon_id, hetero] : pdbx_poly_seq_scheme.find<int, std::string, std::string>("entity_id"_key == entity_id, "seq_id", "mon_id", "hetero"))
 			{
 				if (entity_poly_seq.count(
 						"entity_id"_key == entity_id and
@@ -198,32 +216,41 @@ bool is_valid_pdbx_file(const file &file, const validator &validator, std::error
 					throw std::runtime_error("For each pdbx_poly_seq/struct_asym record there should be exactly one entity_poly_seq record");
 				}
 
-				if ((mon_per_seq_id[seq_id].size() > 1) != hetero)
+				if ((mon_per_seq_id[seq_id].size() > 1) != iequals(hetero, "Y"))
 					throw std::runtime_error("Mismatch between the hetero flag in the poly seq schemes and the number residues per seq_id");
 			}
 
-			for (const auto &[seq_id, mon_ids] : mon_per_seq_id)
-			{
-				for (auto asym_id : struct_asym.find<std::string>("entity_id"_key == entity_id, "id"))
-				{
-					condition cond;
-					
-					for (auto mon_id : mon_ids)
-						cond = std::move(cond) or "label_comp_id"_key == mon_id;
+			// This code proved to take too much time ...
 
-					cond = "label_entity_id"_key == entity_id and
-						"label_asym_id"_key == asym_id and
-						"label_seq_id"_key == seq_id and not std::move(cond);
-					
-					if (atom_site.contains(std::move(cond)))
-						throw std::runtime_error("An atom_site record exists that has no parent in the poly seq scheme categories");
-				}
+			// for (const auto &[seq_id, mon_ids] : mon_per_seq_id)
+			// {
+			// 	for (auto asym_id : struct_asym.find<std::string>("entity_id"_key == entity_id, "id"))
+			// 	{
+			// 		condition cond;
+
+			// 		for (auto mon_id : mon_ids)
+			// 			cond = std::move(cond) or "label_comp_id"_key == mon_id;
+
+			// 		cond = "label_entity_id"_key == entity_id and
+			// 			"label_asym_id"_key == asym_id and
+			// 			"label_seq_id"_key == seq_id and not std::move(cond);
+
+			// 		if (atom_site.contains(std::move(cond)))
+			// 			throw std::runtime_error("An atom_site record exists that has no parent in the poly seq scheme categories");
+			// 	}
+			// }
+
+			// ... so we're using this instead, should be almost the same...
+
+			for (const auto &[comp_id, seq_id] :
+				atom_site.find<std::string, int>("label_entity_id"_key == entity_id, "label_comp_id", "label_seq_id"))
+			{
+				if (not mon_per_seq_id[seq_id].contains(comp_id))
+					throw std::runtime_error("An atom_site record exists that has no parent in the poly seq scheme categories");
 			}
 
 			auto &&[seq, seq_can] = entity_poly.find1<std::optional<std::string>, std::optional<std::string>>("entity_id"_key == entity_id,
 				"pdbx_seq_one_letter_code", "pdbx_seq_one_letter_code_can");
-			
-			std::string::const_iterator si, sci, se, sce;
 
 			auto seq_match = [&](bool can, std::string::const_iterator si, std::string::const_iterator se)
 			{
@@ -260,11 +287,11 @@ bool is_valid_pdbx_file(const file &file, const validator &validator, std::error
 							else
 								letter = '(' + comp_id + ')';
 						}
-						
-						if (iequals(std::string{si, si + letter.length()}, letter))
+
+						if (iequals(std::string{ si, si + static_cast<int>(letter.length()) }, letter))
 						{
 							match = true;
-							si += letter.length();
+							si += static_cast<int>(letter.length());
 							break;
 						}
 						else
@@ -285,7 +312,9 @@ bool is_valid_pdbx_file(const file &file, const validator &validator, std::error
 			}
 			else
 			{
-				seq->erase(std::remove_if(seq->begin(), seq->end(), [](char ch) { return std::isspace(ch); }), seq->end());
+				seq->erase(std::remove_if(seq->begin(), seq->end(), [](char ch)
+							   { return std::isspace(ch); }),
+					seq->end());
 
 				if (not seq_match(false, seq->begin(), seq->end()))
 					throw std::runtime_error("Sequences do not match for entity " + entity_id);
@@ -298,7 +327,9 @@ bool is_valid_pdbx_file(const file &file, const validator &validator, std::error
 			}
 			else
 			{
-				seq_can->erase(std::remove_if(seq_can->begin(), seq_can->end(), [](char ch) { return std::isspace(ch); }), seq_can->end());
+				seq_can->erase(std::remove_if(seq_can->begin(), seq_can->end(), [](char ch)
+								   { return std::isspace(ch); }),
+					seq_can->end());
 
 				if (not seq_match(true, seq_can->begin(), seq_can->end()))
 					throw std::runtime_error("Canonical sequences do not match for entity " + entity_id);
@@ -315,11 +346,10 @@ bool is_valid_pdbx_file(const file &file, const validator &validator, std::error
 		ec = make_error_code(validation_error::not_valid_pdbx);
 	}
 
-	if (not result and (bool)ec)
+	if (not result and ec == std::errc{})
 		ec = make_error_code(validation_error::not_valid_pdbx);
 
 	return result;
 }
 
 } // namespace cif::pdb
-  

src/point.cpp

@@ -24,18 +24,30 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "cif++/point.hpp"
-#include "cif++/matrix.hpp"
+#include "cif++/cif++.hpp"
 
+#include <algorithm>
+#include <array>
 #include <cassert>
+#include <cmath>
+#include <complex>
+#include <cstdint>
+#include <cstdlib>
+#include <initializer_list>
+#include <numbers>
+#include <optional>
 #include <random>
+#include <stdexcept>
+#include <tuple>
+#include <valarray>
+#include <vector>
 
 namespace cif
 {
 
 // --------------------------------------------------------------------
 
-template<typename T>
+template <typename T>
 quaternion_type<T> normalize(quaternion_type<T> q)
 {
 	std::valarray<double> t(4);
@@ -61,7 +73,7 @@ quaternion_type<T> normalize(quaternion_type<T> q)
 
 quaternion construct_from_angle_axis(float angle, point axis)
 {
-	angle = static_cast<float>((angle * kPI / 180) / 2);
+	angle = (angle * std::numbers::pi_v<float> / 180) / 2;
 	auto s = std::sin(angle);
 	auto c = std::cos(angle);
 
@@ -74,14 +86,14 @@ quaternion construct_from_angle_axis(float angle, point axis)
 		static_cast<float>(s * axis.m_z) });
 }
 
-std::tuple<double, point> quaternion_to_angle_axis(quaternion q)
+std::tuple<float, point> quaternion_to_angle_axis(quaternion q)
 {
 	if (q.get_a() > 1)
 		q = normalize(q);
 
 	// angle:
-	double angle = 2 * std::acos(q.get_a());
-	angle = angle * 180 / kPI;
+	float angle = 2 * std::acos(q.get_a());
+	angle = angle * 180 / std::numbers::pi_v<float>;
 
 	// axis:
 	float s = std::sqrt(1 - q.get_a() * q.get_a());
@@ -104,9 +116,9 @@ point center_points(std::vector<point> &Points)
 		t.m_z += pt.m_z;
 	}
 
-	t.m_x /= Points.size();
-	t.m_y /= Points.size();
-	t.m_z /= Points.size();
+	t.m_x /= static_cast<float>(Points.size());
+	t.m_y /= static_cast<float>(Points.size());
+	t.m_z /= static_cast<float>(Points.size());
 
 	for (point &pt : Points)
 	{
@@ -126,10 +138,9 @@ quaternion construct_for_dihedral_angle(point p1, point p2, point p3, point p4,
 	p4 -= p3;
 	p3 -= p3;
 
-	quaternion q;
 	auto axis = -p2;
-
 	float dh = dihedral_angle(p1, p2, p3, p4);
+
 	return construct_from_angle_axis(angle - dh, axis);
 }
 
@@ -161,7 +172,7 @@ double RMSd(const std::vector<point> &a, const std::vector<point> &b)
 		sum += d.sum();
 	}
 
-	return std::sqrt(sum / a.size());
+	return std::sqrt(sum / static_cast<double>(a.size()));
 }
 
 // The next function returns the largest solution for a quartic equation
@@ -293,9 +304,9 @@ quaternion align_points(const std::vector<point> &pa, const std::vector<point> &
 	}
 
 	quaternion q(
-		static_cast<float>(cf(maxR, 0)), 
-		static_cast<float>(cf(maxR, 1)), 
-		static_cast<float>(cf(maxR, 2)), 
+		static_cast<float>(cf(maxR, 0)),
+		static_cast<float>(cf(maxR, 1)),
+		static_cast<float>(cf(maxR, 2)),
 		static_cast<float>(cf(maxR, 3)));
 	q = normalize(q);
 
@@ -306,17 +317,15 @@ quaternion align_points(const std::vector<point> &pa, const std::vector<point> &
 
 point nudge(point p, float offset)
 {
-	static const float kPI_f = static_cast<float>(kPI);
-
 	static std::random_device rd;
 	static std::mt19937_64 rng(rd());
 
-	std::uniform_real_distribution<float> randomAngle(0, 2 * kPI_f);
+	std::uniform_real_distribution<float> randomAngle(0, 2 * std::numbers::pi);
 	std::normal_distribution<float> randomOffset(0, offset);
 
 	float theta = randomAngle(rng);
-	float phi1 = randomAngle(rng) - kPI_f;
-	float phi2 = randomAngle(rng) - kPI_f;
+	float phi1 = randomAngle(rng) - static_cast<float>(std::numbers::pi);
+	float phi2 = randomAngle(rng) - static_cast<float>(std::numbers::pi);
 
 	quaternion q = spherical(1.0f, theta, phi1, phi2);
 
@@ -327,4 +336,251 @@ point nudge(point p, float offset)
 	return p + r;
 }
 
+// --------------------------------------------------------------------
+
+std::tuple<point, float> smallest_sphere_around_2_points(std::array<cif::point, 2> pts)
+{
+	return { (pts[0] + pts[1]) / 2, distance(pts[0], pts[1]) / 2 };
+}
+
+std::tuple<point, float> smallest_sphere_around_3_points(std::array<cif::point, 3> pts)
+{
+	// Find two bisectors
+	auto vz = cross_product(pts[1] - pts[0], pts[2] - pts[0]);
+
+	auto bs1 = cross_product(vz, pts[1] - pts[0]);
+	bs1.normalize();
+
+	auto v1 = (pts[1] - pts[0]);
+	v1.normalize();
+
+	auto s1 = pts[0] + (distance(pts[1], pts[0]) / 2) * v1;
+
+	auto bs2 = cross_product(vz, pts[2] - pts[0]);
+	bs2.normalize();
+
+	auto v2 = (pts[2] - pts[0]);
+	v2.normalize();
+
+	auto s2 = pts[0] + (distance(pts[2], pts[0]) / 2) * v2;
+
+	auto c = line_line_intersection(s1, s1 + bs1, s2, s2 + bs2);
+	if (c)
+		return { *c, distance(*c, pts[0]) };
+
+	// Colinear points I guess, try something else
+	auto l1 = distance_squared(pts[0], pts[1]);
+	auto l2 = distance_squared(pts[0], pts[2]);
+	auto l3 = distance_squared(pts[1], pts[2]);
+
+	if (l1 > l2 and l1 > l3)
+		return smallest_sphere_around_2_points({ pts[0], pts[1] });
+	else if (l2 > l1 and l2 > l3)
+		return smallest_sphere_around_2_points({ pts[0], pts[2] });
+	else
+		return smallest_sphere_around_2_points({ pts[1], pts[2] });
+}
+
+std::tuple<point, float> smallest_sphere_around_4_points(std::array<cif::point, 4> pts)
+{
+	auto t0 = -norm_squared(pts[0]);
+	auto t1 = -norm_squared(pts[1]);
+	auto t2 = -norm_squared(pts[2]);
+	auto t3 = -norm_squared(pts[3]);
+
+	// clang-format off
+	matrix4x4<float> Tm({
+		pts[0].m_x, pts[0].m_y, pts[0].m_z, 1,
+		pts[1].m_x, pts[1].m_y, pts[1].m_z, 1,
+		pts[2].m_x, pts[2].m_y, pts[2].m_z, 1,
+		pts[3].m_x, pts[3].m_y, pts[3].m_z, 1
+	});
+	auto T = determinant(Tm);
+
+	if (T != 0)
+	{
+		matrix4x4<float> Dm({
+			t0, pts[0].m_y, pts[0].m_z, 1,
+			t1, pts[1].m_y, pts[1].m_z, 1,
+			t2, pts[2].m_y, pts[2].m_z, 1,
+			t3, pts[3].m_y, pts[3].m_z, 1
+		});
+		auto D = determinant(Dm) / T;
+		
+		matrix4x4<float> Em({
+			pts[0].m_x, t0, pts[0].m_z, 1,
+			pts[1].m_x, t1, pts[1].m_z, 1,
+			pts[2].m_x, t2, pts[2].m_z, 1,
+			pts[3].m_x, t3, pts[3].m_z, 1
+		});
+		auto E = determinant(Em) / T;
+		
+		matrix4x4<float> Fm({
+			pts[0].m_x, pts[0].m_y, t0, 1,
+			pts[1].m_x, pts[1].m_y, t1, 1,
+			pts[2].m_x, pts[2].m_y, t2, 1,
+			pts[3].m_x, pts[3].m_y, t3, 1
+		});
+		
+		auto F = determinant(Fm) / T;
+		
+		matrix4x4<float> Gm({
+			pts[0].m_x, pts[0].m_y, pts[0].m_z, t0,
+			pts[1].m_x, pts[1].m_y, pts[1].m_z, t1,
+			pts[2].m_x, pts[2].m_y, pts[2].m_z, t2,
+			pts[3].m_x, pts[3].m_y, pts[3].m_z, t3
+		});
+		auto G = determinant(Gm) / T;
+		
+		point center{ -D / 2, -E / 2, -F / 2 };
+		float radius = std::sqrt(D * D + E * E + F * F - 4 * G) / 2;
+
+		// clang-format on
+
+		return { center, radius };
+	}
+
+	// Perhaps some colinear points, try something else:
+
+	for (auto ix : std::initializer_list<std::array<size_t, 4>>{
+			 { 1, 2, 3, 0 },
+			 { 0, 2, 3, 1 },
+			 { 0, 1, 3, 2 },
+			 { 0, 1, 2, 3 },
+		 })
+	{
+		auto [center, radius] =
+			smallest_sphere_around_3_points({ pts[ix[0]], pts[ix[1]], pts[ix[2]] });
+
+		if (distance(pts[ix[3]], center) <= radius)
+			return { center, radius };
+	}
+
+	assert(false);
+	exit(1);
+}
+
+std::tuple<point, float> smallest_sphere_around_all_points(std::vector<point> P, std::vector<point> R)
+{
+	if (P.empty() or R.size() == 4)
+	{
+		switch (R.size())
+		{
+			case 1:
+				return { R[0], 0 };
+
+			case 2:
+				return smallest_sphere_around_2_points({ R[0], R[1] });
+
+			case 3:
+				return smallest_sphere_around_3_points({ R[0], R[1], R[2] });
+
+			case 4:
+				return smallest_sphere_around_4_points({ R[0], R[1], R[2], R[3] });
+
+			default:
+				assert(false);
+		}
+	}
+
+	auto p = P.back();
+	P.pop_back();
+
+	auto [c, r] = smallest_sphere_around_all_points(P, R);
+	assert(not std::isnan(r));
+	if (distance(c, p) <= r)
+		return { c, r };
+
+	R.emplace_back(p);
+	return smallest_sphere_around_all_points(P, R);
+}
+
+bool point_in_circle(point p, std::vector<point> c)
+{
+	switch (c.size())
+	{
+		case 0:
+			return false;
+
+		case 1:
+			return p == c.front();
+
+		case 2:
+		{
+			auto [center, radius] = smallest_sphere_around_2_points({ c[0], c[1] });
+			return cif::distance_squared(p, center) <= radius * radius;
+		}
+
+		case 3:
+		{
+			auto [center, radius] = smallest_sphere_around_3_points({ c[0], c[1], c[2] });
+			return cif::distance_squared(p, center) <= radius * radius;
+		}
+
+		case 4:
+		{
+			auto [center, radius] = smallest_sphere_around_4_points({ c[0], c[1], c[2], c[3] });
+			return cif::distance_squared(p, center) <= radius * radius;
+		}
+
+		default:
+			assert(false);
+			throw std::runtime_error("Error finding smallest sphere");
+	}
+}
+
+std::tuple<point, float> smallest_sphere_around_points(std::vector<point> pts)
+{
+	std::random_device rd;
+	std::mt19937 g(rd());
+
+	std::shuffle(pts.begin(), pts.end(), g);
+
+	std::vector<size_t> cix;
+
+	auto cirle_points = [&]()
+	{
+		std::vector<point> result;
+		for (auto ix : cix)
+			result.emplace_back(pts[ix]);
+		return result;
+	};
+
+	size_t i = 0;
+	while (i < pts.size())
+	{
+		if (std::ranges::find(cix, i) != cix.end() or
+			point_in_circle(pts[i], cirle_points()))
+		{
+			++i;
+		}
+		else
+		{
+			std::erase_if(cix, [i](size_t j)
+				{ return j < i; });
+			cix.push_back(i);
+			if (cix.size() < 4)
+				i = 0;
+			else
+				++i;
+		}
+	}
+
+	switch (cix.size())
+	{
+		case 1:
+			return { pts[cix[0]], 0 };
+		case 2:
+			return smallest_sphere_around_2_points({ pts[cix[0]], pts[cix[1]] });
+		case 3:
+			return smallest_sphere_around_3_points({ pts[cix[0]], pts[cix[1]], pts[cix[2]] });
+		case 4:
+			return smallest_sphere_around_4_points({ pts[cix[0]], pts[cix[1]], pts[cix[2]], pts[cix[3]] });
+		default:
+			assert(false);
+			throw std::runtime_error(std::format("Error finding smallest sphere (cix size: {}, pts size: {})",
+				cix.size(), pts.size()));
+	}
+}
+
 } // namespace cif

src/row.cpp

@@ -24,18 +24,38 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "cif++/category.hpp"
+#include "cif++/cif++.hpp"
+
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <utility>
 
 namespace cif
 {
 
-void row_handle::assign(uint16_t item, std::string_view value, bool updateLinked, bool validate)
-{
-	if (not m_category)
-		throw std::runtime_error("uninitialized row");
+// item_value &row_handle::operator[](uint16_t item_ix)
+// {
+// 	return empty() or item_ix >= m_row->size() ? s_null_item : m_row->operator[](item_ix);
+// }
 
-	m_category->update_value(m_row, item, value, updateLinked, validate);
-}
+// const item_value &row_handle::operator[](uint16_t item_ix) const
+// {
+// 	return empty() or item_ix >= m_row->size() ? s_null_item : m_row->operator[](item_ix);
+// }
+
+// item_value &row_handle::operator[](std::string_view item_name)
+// {
+// 	return operator[](get_item_ix(item_name));
+// }
+
+// const item_value &row_handle::operator[](std::string_view item_name) const
+// {
+// 	return operator[](get_item_ix(item_name));
+// }
 
 uint16_t row_handle::get_item_ix(std::string_view name) const
 {
@@ -53,6 +73,32 @@ std::string_view row_handle::get_item_name(uint16_t ix) const
 	return m_category->get_item_name(ix);
 }
 
+uint16_t const_row_handle::get_item_ix(std::string_view name) const
+{
+	if (not m_category)
+		throw std::runtime_error("uninitialized row");
+
+	return m_category->get_item_ix(name);
+}
+
+std::string_view const_row_handle::get_item_name(uint16_t ix) const
+{
+	if (not m_category)
+		throw std::runtime_error("uninitialized row");
+
+	return m_category->get_item_name(ix);
+}
+
+// --------------------------------------------------------------------
+
+void row_handle::assign(uint16_t item, item_value value, bool updateLinked, bool validate)
+{
+	if (not m_category)
+		throw std::runtime_error("uninitialized row");
+
+	m_category->update_value(m_row, item, std::move(value), updateLinked, validate);
+}
+
 uint16_t row_handle::add_item(std::string_view name)
 {
 	if (not m_category)
@@ -61,53 +107,44 @@ uint16_t row_handle::add_item(std::string_view name)
 	return m_category->add_item(name);
 }
 
-void row_handle::swap(uint16_t item, row_handle &b)
-{
-	if (not m_category)
-		throw std::runtime_error("uninitialized row");
-
-	m_category->swap_item(item, *this, b);
-}
-
 // --------------------------------------------------------------------
 
-row_initializer::row_initializer(row_handle rh)
+row_initializer::row_initializer(const_row_handle rh)
 {
 	if (not rh.m_category)
 		throw std::runtime_error("uninitialized row");
 
 	assert(rh.m_row);
 
-	row *r = rh.get_row();
+	auto r = rh.get_row();
 	auto &cat = *rh.m_category;
 
-	for (uint16_t ix = 0; ix < r->size(); ++ix)
+	for (uint16_t ix = 0; std::cmp_less(ix, r->size()); ++ix)
 	{
 		auto &i = r->operator[](ix);
-		if (not i)
-			continue;
-		emplace_back(cat.get_item_name(ix), i.text());
+		emplace_back(cat.get_item_name(ix), i);
 	}
 }
 
-void row_initializer::set_value(std::string_view name, std::string_view value)
+void row_initializer::set_value(std::string name, item_value value)
 {
 	for (auto &i : *this)
 	{
 		if (i.name() == name)
 		{
-			i.value(value);
+			i.value(std::move(value));
 			return;
 		}
 	}
 
-	emplace_back(name, value);
+	emplace_back(std::move(name), std::move(value));
 }
 
-void row_initializer::set_value_if_empty(std::string_view name, std::string_view value)
+void row_initializer::set_value_if_empty(std::string name, item_value value)
 {
-	if (find_if(begin(), end(), [name](auto &i) { return i.name() == name; }) == end())
-		emplace_back(name, value);
+	if (std::ranges::find_if(*this, [name](auto &i)
+			{ return i.name() == name; }) == end())
+		emplace_back(std::move(name), std::move(value));
 }
 
-} // namespace cif
+} // namespace cif

src/symmetry.cpp

@@ -25,13 +25,27 @@
  */
 
 #include "cif++/symmetry.hpp"
-#include "cif++/datablock.hpp"
-#include "cif++/point.hpp"
-
-#include <stdexcept>
-
+#include "cif++/cif++.hpp"
 #include "symop_table_data.hpp"
 
+#include <array>
+#include <charconv>
+#include <cmath>
+#include <cstddef>
+#include <cstdint>
+#include <limits>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <system_error>
+#include <tuple>
+#include <vector>
+
+#if defined(_MSC_VER)
+# pragma warning(disable : 5054) // warning C5054: operator '&': deprecated between enumerations of different types
+# pragma warning(disable : 4127) // conditional expression is constant
+#endif
+
 #include <Eigen/Eigen>
 
 namespace cif
@@ -62,38 +76,38 @@ cell::cell(const datablock &db)
 
 void cell::init()
 {
-	auto alpha = (m_alpha * kPI) / 180;
-	auto beta = (m_beta * kPI) / 180;
-	auto gamma = (m_gamma * kPI) / 180;
+	auto alpha = (m_alpha * std::numbers::pi_v<float>) / 180;
+	auto beta = (m_beta * std::numbers::pi_v<float>) / 180;
+	auto gamma = (m_gamma * std::numbers::pi_v<float>) / 180;
 
 	auto alpha_star = std::acos((std::cos(gamma) * std::cos(beta) - std::cos(alpha)) / (std::sin(beta) * std::sin(gamma)));
 
 	m_orthogonal = identity_matrix(3);
 
-	m_orthogonal(0, 0) = static_cast<float>(m_a);
-	m_orthogonal(0, 1) = static_cast<float>(m_b * std::cos(gamma));
-	m_orthogonal(0, 2) = static_cast<float>(m_c * std::cos(beta));
-	m_orthogonal(1, 1) = static_cast<float>(m_b * std::sin(gamma));
-	m_orthogonal(1, 2) = static_cast<float>(-m_c * std::sin(beta) * std::cos(alpha_star));
-	m_orthogonal(2, 2) = static_cast<float>(m_c * std::sin(beta) * std::sin(alpha_star));
+	m_orthogonal(0, 0) = m_a;
+	m_orthogonal(0, 1) = m_b * std::cos(gamma);
+	m_orthogonal(0, 2) = m_c * std::cos(beta);
+	m_orthogonal(1, 1) = m_b * std::sin(gamma);
+	m_orthogonal(1, 2) = m_c * std::sin(beta) * std::cos(alpha_star);
+	m_orthogonal(2, 2) = m_c * std::sin(beta) * std::sin(alpha_star);
 
 	m_fractional = inverse(m_orthogonal);
 }
 
 float cell::get_volume() const
 {
-	auto alpha = (m_alpha * kPI) / 180;
-	auto beta = (m_beta * kPI) / 180;
-	auto gamma = (m_gamma * kPI) / 180;
+	auto alpha = (m_alpha * std::numbers::pi_v<float>) / 180;
+	auto beta = (m_beta * std::numbers::pi_v<float>) / 180;
+	auto gamma = (m_gamma * std::numbers::pi_v<float>) / 180;
 
 	auto cos_alpha = std::cos(alpha);
 	auto cos_beta = std::cos(beta);
 	auto cos_gamma = std::cos(gamma);
 
-	auto vol = m_a * m_b * m_c;
+	double vol = m_a * m_b * m_c;
 	vol *= std::sqrt(1.0f - cos_alpha * cos_alpha - cos_beta * cos_beta - cos_gamma * cos_gamma + 2.0f * cos_alpha * cos_beta * cos_gamma);
 
-	return vol;
+	return static_cast<float>(vol);
 }
 
 // --------------------------------------------------------------------
@@ -111,7 +125,7 @@ sym_op::sym_op(std::string_view s)
 	m_tb = r.ptr[2] - '0';
 	m_tc = r.ptr[3] - '0';
 
-	if ((bool)r.ec or rnri > 192 or r.ptr[0] != '_' or m_ta > 9 or m_tb > 9 or m_tc > 9)
+	if (r.ec != std::errc{} or rnri > 192 or r.ptr[0] != '_' or m_ta > 9 or m_tb > 9 or m_tc > 9)
 		throw std::invalid_argument("Could not convert string into sym_op");
 }
 
@@ -119,13 +133,13 @@ std::string sym_op::string() const
 {
 	char b[9];
 	auto r = std::to_chars(b, b + sizeof(b), m_nr);
-	if ((bool)r.ec or r.ptr > b + 4)
+	if (r.ec != std::errc{} or r.ptr > b + 4)
 		throw std::runtime_error("Could not write out symmetry operation to string");
 
 	*r.ptr++ = '_';
-	*r.ptr++ = '0' + m_ta;
-	*r.ptr++ = '0' + m_tb;
-	*r.ptr++ = '0' + m_tc;
+	*r.ptr++ = static_cast<char>('0' + m_ta);
+	*r.ptr++ = static_cast<char>('0' + m_tb);
+	*r.ptr++ = static_cast<char>('0' + m_tc);
 	*r.ptr = 0;
 
 	return { b, static_cast<std::size_t>(r.ptr - b) };
@@ -182,7 +196,7 @@ transformation operator*(const transformation &lhs, const transformation &rhs)
 	auto t = lhs.m_rotation * rhs.m_translation;
 	t = t + lhs.m_translation;
 
-	return transformation(r, t);
+	return { r, t };
 }
 
 transformation inverse(const transformation &t)
@@ -279,12 +293,7 @@ point spacegroup::operator()(const point &pt, const cell &c, sym_op symop) const
 	t.m_translation.m_y += symop.m_tb - 5;
 	t.m_translation.m_z += symop.m_tc - 5;
 
-	auto fpt = fractional(pt, c);
-	auto o = offsetToOriginFractional(fpt);
-
-	auto spt = t(fpt + o) - o;
-
-	return orthogonal(spt, c);
+	return orthogonal(t(fractional(pt, c)), c);
 }
 
 point spacegroup::inverse(const point &pt, const cell &c, sym_op symop) const
@@ -298,13 +307,8 @@ point spacegroup::inverse(const point &pt, const cell &c, sym_op symop) const
 	t.m_translation.m_y += symop.m_tb - 5;
 	t.m_translation.m_z += symop.m_tc - 5;
 
-	auto fpt = fractional(pt, c);
-	auto o = offsetToOriginFractional(fpt);
-
 	auto it = cif::inverse(t);
-	auto spt = it(fpt + o) - o;
-
-	return orthogonal(spt, c);
+	return orthogonal(it(fractional(pt, c)), c);
 }
 
 // --------------------------------------------------------------------
@@ -340,9 +344,8 @@ int get_space_group_number(std::string_view spacegroup)
 	// not found, see if we can find a match based on xHM name
 	if (result == 0)
 	{
-		for (std::size_t i = 0; i < kNrOfSpaceGroups; ++i)
+		for (const auto &sp : kSpaceGroups)
 		{
-			auto &sp = kSpaceGroups[i];
 			if (sp.xHM == spacegroup)
 			{
 				result = sp.nr;
@@ -450,9 +453,9 @@ std::tuple<float, point, sym_op> crystal::closest_symmetry_copy(point a, point b
 
 	a = orthogonal(fa, m_cell);
 
-	for (std::size_t i = 0; i < m_spacegroup.size(); ++i)
+	for (uint8_t i = 0; std::cmp_less(i, m_spacegroup.size()); ++i)
 	{
-		sym_op s(static_cast<uint8_t>(i + 1));
+		sym_op s(i + 1);
 		auto &t = m_spacegroup[i];
 
 		auto fsb = t(fb);

src/symop-map-generator.cpp

@@ -280,7 +280,7 @@ int main(int argc, char* const argv[])
 			if (std::isdigit(line[0]))	// start of new spacegroup
 			{
 				auto r = std::from_chars(line.data(), line.data() + line.length(), sgnr);
-				if ((bool)r.ec)
+				if (r.ec != std::errc{})
 					throw std::runtime_error("Error parsing symop.lib file");
 				rnr = 1;
 				continue;

src/text.cpp

@@ -28,6 +28,12 @@
 
 #include <algorithm>
 #include <cassert>
+#include <cctype>
+#include <stdexcept>
+
+#if defined(USE_FAST_FLOAT)
+# include "fast_float/fast_float.h"
+#endif
 
 namespace cif
 {
@@ -56,31 +62,29 @@ const uint8_t kCharToLowerMap[256] = {
 
 // --------------------------------------------------------------------
 
-bool iequals(std::string_view a, std::string_view b)
+bool iequals(std::string_view a, std::string_view b) noexcept
 {
 	bool result = a.length() == b.length();
 	for (auto ai = a.begin(), bi = b.begin(); result and ai != a.end(); ++ai, ++bi)
-		result = kCharToLowerMap[uint8_t(*ai)] == kCharToLowerMap[uint8_t(*bi)];
-	// result = tolower(*ai) == tolower(*bi);
+		result = kCharToLowerMap[static_cast<uint8_t>(*ai)] == kCharToLowerMap[static_cast<uint8_t>(*bi)];
 	return result;
 }
 
-bool iequals(const char *a, const char *b)
+bool iequals(const char *a, const char *b) noexcept
 {
 	bool result = true;
 	for (; result and *a and *b; ++a, ++b)
-		result = kCharToLowerMap[uint8_t(*a)] == kCharToLowerMap[uint8_t(*b)];
-
+		result = kCharToLowerMap[static_cast<uint8_t>(*a)] == kCharToLowerMap[static_cast<uint8_t>(*b)];
 	return result and *a == *b;
 }
 
-int icompare(std::string_view a, std::string_view b)
+int icompare(std::string_view a, std::string_view b) noexcept
 {
 	int d = 0;
 	auto ai = a.begin(), bi = b.begin();
 
 	for (; d == 0 and ai != a.end() and bi != b.end(); ++ai, ++bi)
-		d = (int)kCharToLowerMap[uint8_t(*ai)] - (int)kCharToLowerMap[uint8_t(*bi)];
+		d = static_cast<int>(kCharToLowerMap[static_cast<uint8_t>(*ai)]) - static_cast<int>(kCharToLowerMap[static_cast<uint8_t>(*bi)]);
 
 	if (d == 0)
 	{
@@ -93,12 +97,12 @@ int icompare(std::string_view a, std::string_view b)
 	return d;
 }
 
-int icompare(const char *a, const char *b)
+int icompare(const char *a, const char *b) noexcept
 {
 	int d = 0;
 
 	for (; d == 0 and *a != 0 and *b != 0; ++a, ++b)
-		d = (int)kCharToLowerMap[uint8_t(*a)] - (int)kCharToLowerMap[uint8_t(*b)];
+		d = static_cast<int>(kCharToLowerMap[static_cast<uint8_t>(*a)]) - static_cast<int>(kCharToLowerMap[static_cast<uint8_t>(*b)]);
 
 	if (d == 0)
 	{
@@ -194,7 +198,7 @@ void trim_left(std::string &s)
 
 	while (in != s.end() and std::isspace(*in))
 		++in;
-	
+
 	if (in == s.end())
 		s.clear();
 	else if (in != out)
@@ -214,7 +218,7 @@ void trim(std::string &s)
 
 	while (in != end and std::isspace(*in))
 		++in;
-	
+
 	if (in == end)
 		s.clear();
 	else if (in != out)
@@ -263,7 +267,7 @@ std::string cif_id_for_number(int number)
 		number = (number - r) / 26 - 1;
 	} while (number >= 0);
 
-	std::reverse(result.begin(), result.end());
+	std::ranges::reverse(result);
 
 	assert(not result.empty());
 
@@ -385,7 +389,7 @@ std::string::const_iterator nextLineBreak(std::string::const_iterator text, std:
 		/* JT */ { DBK, PBK, PBK, IBK, IBK, IBK, PBK, PBK, PBK, DBK, IBK, DBK, DBK, DBK, IBK, IBK, IBK, DBK, DBK, PBK, CIB, PBK, DBK, DBK, DBK, DBK, IBK },
 	};
 
-	uint8_t ch = static_cast<uint8_t>(*text);
+	auto ch = static_cast<uint8_t>(*text);
 
 	LineBreakClass cls;
 
@@ -489,7 +493,7 @@ std::vector<std::string> wrapLine(const std::string &text, std::size_t width)
 		j = i;
 	}
 
-	reverse(result.begin(), result.end());
+	std::ranges::reverse(result);
 
 	return result;
 }
@@ -501,7 +505,7 @@ std::vector<std::string> word_wrap(const std::string &text, std::size_t width)
 	{
 		if (p.empty())
 		{
-			result.push_back("");
+			result.emplace_back("");
 			continue;
 		}
 
@@ -512,4 +516,32 @@ std::vector<std::string> word_wrap(const std::string &text, std::size_t width)
 	return result;
 }
 
-} // namespace cif
+#if defined(USE_FAST_FLOAT)
+
+template <typename T>
+std::from_chars_result ff_charconv<T, typename std::enable_if_t<std::is_floating_point_v<T>>>::from_chars(const char *a, const char *b, T &v)
+{
+	auto r = fast_float::from_chars(a, b, v);
+	return { r.ptr, r.ec };
+}
+
+template struct ff_charconv<float>;
+template struct ff_charconv<double>;
+// template struct ff_charconv<long double>;
+
+# ifdef __STDCPP_FLOAT64_T__
+template struct ff_charconv<std::float64_t>;
+# endif
+# ifdef __STDCPP_FLOAT32_T__
+template struct ff_charconv<std::float32_t>;
+# endif
+# ifdef __STDCPP_FLOAT16_T__
+template struct ff_charconv<std::float16_t>;
+# endif
+# ifdef __STDCPP_BFLOAT16_T__
+template struct ff_charconv<std::bfloat16_t>;
+# endif
+
+#endif
+
+} // namespace cif

src/validate.cpp

@@ -25,14 +25,30 @@
  */
 
 #include "cif++/validate.hpp"
-#include "cif++/category.hpp"
-#include "cif++/dictionary_parser.hpp"
-#include "cif++/gzio.hpp"
-#include "cif++/utilities.hpp"
+
+#include "cif++/cif++.hpp"
+#include "cif++/text.hpp"
 
 #include <cassert>
-#include <fstream>
+#include <charconv>
+#include <cstddef>
+#include <filesystem>
+#include <format>
+#include <iomanip>
 #include <iostream>
+#include <list>
+#include <memory>
+#include <mutex>
+#include <optional>
+#include <ranges>
+#include <set>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <system_error>
+#include <tuple>
+#include <utility>
+#include <vector>
 
 // The validator depends on regular expressions. Unfortunately,
 // the implementation of std::regex in g++ is buggy and crashes
@@ -62,14 +78,6 @@ validation_exception::validation_exception(std::error_code ec, std::string_view
 
 // --------------------------------------------------------------------
 
-// struct regex_impl : public regex
-// {
-// 	regex_impl(std::string_view rx)
-// 		: regex(rx.begin(), rx.end(), regex::extended | regex::optimize)
-// 	{
-// 	}
-// };
-
 struct regex_impl
 {
 	regex_impl(std::string_view rx);
@@ -81,22 +89,22 @@ struct regex_impl
 	bool match(std::string_view v) const;
 
   private:
-
-	pcre2_code *m_rx = nullptr;
+	pcre2_code_8 *m_rx = nullptr;
 	pcre2_match_data *m_data = nullptr;
+	mutable std::mutex m_mutex;
 };
 
 regex_impl::regex_impl(std::string_view rx)
 {
 	int err_code;
 	size_t err_offset;
-	m_rx = pcre2_compile((PCRE2_SPTR)rx.data(), rx.length(), 0, &err_code, &err_offset, nullptr);
+	m_rx = pcre2_compile(reinterpret_cast<PCRE2_SPTR>(rx.data()), rx.length(), 0, &err_code, &err_offset, nullptr);
 	if (m_rx == nullptr)
 	{
-		PCRE2_UCHAR buffer[256];
-		int n = pcre2_get_error_message(err_code, buffer, sizeof(buffer));
+		char buffer[256];
+		int n = pcre2_get_error_message(err_code, reinterpret_cast<unsigned char *>(&buffer[0]), sizeof(buffer));
 
-		throw std::runtime_error(std::string("PCRE2 compilation failed: ") + std::string{ (char *)buffer, (char *)buffer + n });
+		throw std::runtime_error(std::string("PCRE2 compilation failed: ") + std::string{ buffer, buffer + n });
 	}
 
 	m_data = pcre2_match_data_create_from_pattern(m_rx, nullptr);
@@ -104,6 +112,8 @@ regex_impl::regex_impl(std::string_view rx)
 
 regex_impl::~regex_impl()
 {
+	std::unique_lock lock(m_mutex);
+
 	if (m_data)
 		pcre2_match_data_free(m_data);
 
@@ -113,9 +123,11 @@ regex_impl::~regex_impl()
 
 bool regex_impl::match(std::string_view v) const
 {
+	std::unique_lock lock(m_mutex);
+
 	bool result = false;
 
-	if (int rc = pcre2_match(m_rx, (PCRE2_SPTR)v.data(), v.length(), 0, 0, m_data, nullptr); rc >= 0)
+	if (int rc = pcre2_match(m_rx, reinterpret_cast<PCRE2_SPTR>(v.data()), v.length(), 0, 0, m_data, nullptr); rc >= 0)
 		result = true;
 	else if (rc != PCRE2_ERROR_NOMATCH)
 		std::cerr << "Error matching with pcre\n";
@@ -158,136 +170,99 @@ type_validator::type_validator(std::string_view name, DDL_PrimitiveType type, st
 {
 }
 
-type_validator::type_validator(const type_validator &tv)
-	: m_name(tv.m_name)
-	, m_primitive_type(tv.m_primitive_type)
-	, m_rx(tv.m_rx)
+int type_validator::compare(const item_value &a, const item_value &b) const
 {
-}
-
-type_validator::~type_validator()
-{
-}
-
-int type_validator::compare(std::string_view a, std::string_view b) const
-{
-	int result = 0;
-
-	if (a.empty())
-		result = b.empty() ? 0 : -1;
-	else if (b.empty())
-		result = a.empty() ? 0 : +1;
-	else
+	switch (m_primitive_type)
 	{
-		switch (m_primitive_type)
+		using enum DDL_PrimitiveType;
+
+		case Numb:
 		{
-			case DDL_PrimitiveType::Numb:
-			{
-				double da, db;
+			if (a.is_number() and b.is_number())
+				return a.compare(b);
 
-				using namespace cif;
-				using namespace std;
+			auto da = a.get<double>();
+			auto db = b.get<double>();
 
-				std::from_chars_result ra, rb;
-
-				ra = selected_charconv<double>::from_chars(a.data(), a.data() + a.length(), da);
-				rb = selected_charconv<double>::from_chars(b.data(), b.data() + b.length(), db);
-
-				if (not(bool) ra.ec and not(bool) rb.ec)
-				{
-					auto d = da - db;
-					if (std::abs(d) > std::numeric_limits<double>::epsilon())
-					{
-						if (d > 0)
-							result = 1;
-						else if (d < 0)
-							result = -1;
-					}
-				}
-				else if ((bool)ra.ec)
-					result = 1;
-				else
-					result = -1;
-				break;
-			}
-
-			case DDL_PrimitiveType::UChar:
-			case DDL_PrimitiveType::Char:
-			{
-				// CIF is guaranteed to have ascii only, therefore this primitive code will do
-				// also, we're collapsing spaces
-
-				auto ai = a.begin(), bi = b.begin();
-				for (;;)
-				{
-					if (ai == a.end())
-					{
-						if (bi != b.end())
-							result = -1;
-						break;
-					}
-					else if (bi == b.end())
-					{
-						result = 1;
-						break;
-					}
-
-					char ca = *ai;
-					char cb = *bi;
-
-					if (m_primitive_type == DDL_PrimitiveType::UChar)
-					{
-						ca = tolower(ca);
-						cb = tolower(cb);
-					}
-
-					result = ca - cb;
-
-					if (result != 0)
-						break;
-
-					if (ca == ' ')
-					{
-						while (ai[1] == ' ')
-							++ai;
-						while (bi[1] == ' ')
-							++bi;
-					}
-
-					++ai;
-					++bi;
-				}
-
-				break;
-			}
+			return da < db
+			           ? -1
+			       : da > db
+			           ? 1
+			           : 0;
 		}
-	}
 
-	return result;
+		case UChar:
+			if (a.is_string() and b.is_string())
+				return a.compare(b, true);
+
+			return icompare(a.str(), b.str());
+
+		case Char:
+			if (a.is_string() and b.is_string())
+				return a.compare(b, false);
+
+			return a.str().compare(b.str());
+
+		default:
+			throw std::runtime_error("invalid primitive type");
+	}
 }
 
 // --------------------------------------------------------------------
 
-void item_validator::operator()(std::string_view value) const
+void item_validator::validate_value(const item_value &value) const
 {
 	std::error_code ec;
 	if (not validate_value(value, ec))
-		throw std::system_error(ec, std::string{ value } + " does not match rx for " + m_item_name);
+		throw std::system_error(ec, std::format("'{}' is not a valid value for {}", value.str(), m_item_name));
 }
 
-bool item_validator::validate_value(std::string_view value, std::error_code &ec) const noexcept
+bool item_validator::validate_value(const item_value &value, std::error_code &ec) const noexcept
 {
 	ec.clear();
 
-	if (not value.empty() and value != "?" and value != ".")
+	if (not value.empty())
 	{
-		if (m_type != nullptr and not m_type->m_rx->match(value))
-			ec = make_error_code(validation_error::value_does_not_match_rx);
-		else if (not m_enums.empty() and m_enums.count(std::string{ value }) == 0)
-			ec = make_error_code(validation_error::value_is_not_in_enumeration_list);
+		if (m_type != nullptr)
+		{
+			if (m_type->m_primitive_type == DDL_PrimitiveType::Numb)
+			{
+				if (not value.is_number())
+					ec = make_error_code(validation_error::value_is_not_a_number);
+			}
+			else
+			{
+				if (value.is_number())
+					ec = make_error_code(validation_error::value_is_not_a_char_string);
+				else
+				{
+					try
+					{
+						if (not m_type->m_rx->match(value.sv()))
+							ec = make_error_code(validation_error::value_does_not_match_rx);
+					}
+					catch (...)
+					{
+						ec = make_error_code(validation_error::value_does_not_match_rx);
+					}
+
+					if (ec == std::errc{} and not m_enums.empty())
+					{
+						bool valid =
+							m_type->m_primitive_type == DDL_PrimitiveType::UChar ? //
+								m_enums.contains(cif::to_lower_copy(value.sv()))
+																				 : //
+								m_enums.contains(std::string{ value.sv() });
+
+						if (not valid)
+							ec = make_error_code(validation_error::value_is_not_in_enumeration_list);
+					}
+				}
+			}
+		}
 	}
 
-	return not(bool) ec;
+	return ec == std::errc{};
 }
 
 // --------------------------------------------------------------------
@@ -299,15 +274,20 @@ void category_validator::add_item_validator(item_validator &&v)
 
 	v.m_category = m_name;
 
-	auto r = m_item_validators.insert(std::move(v));
-	if (not r.second and VERBOSE >= 4)
-		std::cout << "Could not add validator for item " << v.m_item_name << " to category " << m_name << '\n';
+	auto i = std::ranges::find(m_item_validators, v);
+	if (i != m_item_validators.end())
+	{
+		if (VERBOSE >= 4)
+			std::cout << "Could not add validator for item " << v.m_item_name << " to category " << m_name << '\n';
+	}
+	else
+		m_item_validators.emplace_back(std::move(v));
 }
 
 const item_validator *category_validator::get_validator_for_item(std::string_view item_name) const
 {
 	const item_validator *result = nullptr;
-	auto i = m_item_validators.find(item_validator{ std::string(item_name) });
+	auto i = std::ranges::find(m_item_validators, item_validator{ std::string(item_name) });
 	if (i != m_item_validators.end())
 		result = &*i;
 	else if (VERBOSE > 4)
@@ -339,15 +319,6 @@ const item_validator *category_validator::get_validator_for_aliased_item(std::st
 
 // --------------------------------------------------------------------
 
-validator::validator(const validator &rhs)
-	: m_audit_conform(rhs.m_audit_conform)
-	, m_strict(rhs.m_strict)
-	, m_type_validators(rhs.m_type_validators)
-	, m_category_validators(rhs.m_category_validators)
-	, m_link_validators(rhs.m_link_validators)
-{
-}
-
 void swap(validator &a, validator &b) noexcept
 {
 	std::swap(a.m_audit_conform, b.m_audit_conform);
@@ -364,9 +335,7 @@ void validator::parse(std::istream &is)
 
 void validator::add_type_validator(type_validator &&v)
 {
-	auto r = m_type_validators.insert(std::move(v));
-	if (not r.second and VERBOSE > 4)
-		std::cout << "Could not add validator for type " << v.m_name << '\n';
+	m_type_validators.emplace(v);
 }
 
 const type_validator *validator::get_validator_for_type(std::string_view typeCode) const
@@ -376,16 +345,12 @@ const type_validator *validator::get_validator_for_type(std::string_view typeCod
 	auto i = m_type_validators.find(type_validator{ std::string(typeCode), DDL_PrimitiveType::Char, {} });
 	if (i != m_type_validators.end())
 		result = &*i;
-	else if (VERBOSE > 4)
-		std::cout << "No validator for type " << typeCode << '\n';
 	return result;
 }
 
 void validator::add_category_validator(category_validator &&v)
 {
-	auto r = m_category_validators.insert(std::move(v));
-	if (not r.second and VERBOSE > 4)
-		std::cout << "Could not add validator for category " << v.m_name << '\n';
+	m_category_validators.emplace(v);
 }
 
 const category_validator *validator::get_validator_for_category(std::string_view category) const
@@ -394,8 +359,6 @@ const category_validator *validator::get_validator_for_category(std::string_view
 	auto i = m_category_validators.find(category_validator{ std::string(category) });
 	if (i != m_category_validators.end())
 		result = &*i;
-	else if (VERBOSE > 4)
-		std::cout << "No validator for category " << category << '\n';
 	return result;
 }
 
@@ -483,15 +446,31 @@ void validator::report_error(std::error_code ec, bool fatal) const
 		std::cerr << ec.message() << '\n';
 }
 
-void validator::report_error(std::error_code ec, std::string_view category,
-	std::string_view item, bool fatal) const
+void validator::report_error(std::error_code ec, std::string value,
+	std::string_view category, std::string_view item, bool fatal) const
 {
-	auto ex = item.empty() ? validation_exception(ec, category) : validation_exception(ec, category, item);
-
 	if (m_strict or fatal)
-		throw ex;
-	else if (VERBOSE > 0)
-		std::cerr << ex.what() << '\n';
+	{
+		if (item.empty())
+			throw validation_exception(ec, category);
+		else
+			throw validation_exception(ec, category, item);
+	}
+
+	if (VERBOSE > 0)
+	{
+		if (value.empty())
+			std::cerr << ec.message()
+					  << "; category: " << std::quoted(category)
+					  << " item: " << std::quoted(item)
+					  << '\n';
+		else
+			std::cerr << ec.message()
+					  << "; value: " << std::quoted(value)
+					  << "; category: " << std::quoted(category)
+					  << " item: " << std::quoted(item)
+					  << '\n';
+	}
 }
 
 void validator::fill_audit_conform(category &audit_conform) const
@@ -544,57 +523,79 @@ validator_factory &validator_factory::instance()
 	return s_instance;
 }
 
-const validator &validator_factory::get(std::string_view dictionary_name)
+const validator *validator_factory::get(std::string_view dictionary_name)
 {
 	category audit_conform("audit_conform");
-	for (auto part : cif::split(dictionary_name, ";", true))
+	for (auto part : cif::split(dictionary_name, ";,", true))
 		audit_conform.emplace({ { "dict_name", part } });
 
 	return get(audit_conform);
 }
 
-const validator &validator_factory::get(const category &audit_conform)
+const validator *validator_factory::get(const category &audit_conform)
 {
-	if (audit_conform.empty())
-		throw std::runtime_error("Empty audit_conform category, cannot create a validator");
+	const validator *result = nullptr;
 
-	std::lock_guard lock(m_mutex);
+	std::scoped_lock lock(m_mutex);
 
 	// Check existing first
 	for (auto &v : m_validators)
 	{
 		if (v.matches_audit_conform(audit_conform))
-			return v;
+			result = &v;
 	}
 
 	// If the audit conform contains only one record, this is easy
-	if (audit_conform.size() == 1)
+	if (result == nullptr and audit_conform.size() == 1)
 	{
-		const auto &[name, version] = audit_conform.front().get<std::string, std::optional<std::string>>("dict_name", "dict_version");
-		return m_validators.emplace_back(construct_validator(name, version));
+		const auto &[name, version] =
+			audit_conform.front().get<std::string, std::optional<std::string>>("dict_name", "dict_version");
+		if (not name.empty())
+			result = &m_validators.emplace_back(construct_validator(name, version));
 	}
 
-	// A new, merged dictionary
-
-	std::optional<validator> v;
-	for (const auto &[name, version] : audit_conform.rows<std::string, std::optional<std::string>>("dict_name", "dict_version"))
+	if (result == nullptr)
 	{
-		if (not v)
-			v = construct_validator(name, version);
-		else
+		// A new, merged dictionary
+		std::optional<validator> v;
+		for (const auto &[name, version] : audit_conform.rows<std::string, std::optional<std::string>>("dict_name", "dict_version"))
 		{
-			auto data = load_resource(name);
-			if (not data)
-				throw std::runtime_error("Could not load dictionary " + std::string{ name });
+			if (name.empty())
+				continue;
 
-			v->parse(*data);
+			if (not v) // first dict
+				v = construct_validator(name, version);
+			else // additional/extending dict
+			{
+				auto data = load_resource(name);
+				if (not data)
+					throw std::runtime_error("Could not load dictionary " + std::string{ name });
+
+				v->parse(*data);
+			}
 		}
+
+		if (v)
+			result = &m_validators.emplace_back(std::move(*v));
 	}
 
-	if (not v)
-		throw std::runtime_error("Missing dictionary information?");
+	return result;
+}
 
-	return m_validators.emplace_back(std::move(*v));
+const validator &validator_factory::operator[](const category &audit_conform)
+{
+	auto v = get(audit_conform);
+	if (v == nullptr)
+		throw std::runtime_error("Could not load dictionary for audit_conform");
+	return *v;
+}
+
+const validator &validator_factory::operator[](std::string_view dictionary_name)
+{
+	auto v = get(dictionary_name);
+	if (v == nullptr)
+		throw std::runtime_error("Could not load dictionary for " + std::string{ dictionary_name });
+	return *v;
 }
 
 validator validator_factory::construct_validator(std::string_view name, std::optional<std::string> version)
@@ -613,7 +614,7 @@ validator validator_factory::construct_validator(std::string_view name, std::opt
 		not v.matches_audit_conform(category{ "audit_conform", //
 			{ { "dict_name", name }, { "dict_version", version } } }))
 	{
-		std::clog << "Invalid dictionary?\n";
+		std::clog << "Loaded dictionary does not match name=" << name << " and version=" << version.value_or("''") << "\n";
 	}
 
 	return v;

test/CMakeLists.txt

@@ -1,19 +1,39 @@
-# We're using the older version 2 of Catch2
+# SPDX-License-Identifier: BSD-2-Clause
+# 
+# Copyright (c) 2025  NKI/AVL, Netherlands Cancer Institute
+# 
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+# 
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-if(NOT(Catch2_FOUND OR TARGET Catch2))
-	find_package(Catch2 QUIET)
+if(NOT (Catch2_FOUND OR TARGET Catch2))
+	find_package(Catch2 3 QUIET)
 
 	if(NOT Catch2_FOUND)
-		include(FetchContent)
-
 		FetchContent_Declare(
 			Catch2
 			GIT_REPOSITORY https://github.com/catchorg/Catch2.git
-			GIT_TAG v2.13.9)
+			GIT_TAG v3.4.0)
 
 		FetchContent_MakeAvailable(Catch2)
 
-		set(Catch2_VERSION "2.13.9")
+		target_compile_features(Catch2 PRIVATE cxx_std_20)
 	endif()
 endif()
 
@@ -23,24 +43,20 @@ list(
 	unit-v2
 	unit-3d
 	model
-	query
+	# query
 	rename-compound
 	sugar
 	spinner
-	# reconstruction
+	reconstruction
 	validate-pdbx
-	)
+	cql
+	matrix
+)
 
 add_library(test-main OBJECT "${CMAKE_CURRENT_SOURCE_DIR}/test-main.cpp")
 
 target_link_libraries(test-main cifpp::cifpp Catch2::Catch2)
 
-if("${Catch2_VERSION}" VERSION_LESS 3.0.0)
-	target_compile_definitions(test-main PUBLIC CATCH22=1)
-else()
-	target_compile_definitions(test-main PUBLIC CATCH22=0)
-endif()
-
 foreach(CIFPP_TEST IN LISTS CIFPP_tests)
 	set(CIFPP_TEST "${CIFPP_TEST}-test")
 	set(CIFPP_TEST_SOURCE "${CMAKE_CURRENT_SOURCE_DIR}/${CIFPP_TEST}.cpp")
@@ -48,29 +64,17 @@ foreach(CIFPP_TEST IN LISTS CIFPP_tests)
 	add_executable(
 		${CIFPP_TEST} ${CIFPP_TEST_SOURCE} $<TARGET_OBJECTS:test-main>)
 
-	if(${Catch2_VERSION} VERSION_GREATER_EQUAL 3.0.0)
-		target_compile_definitions(${CIFPP_TEST} PUBLIC CATCH22=0)
-	else()
-		target_compile_definitions(${CIFPP_TEST} PUBLIC CATCH22=1)
-	endif()
-
 	target_link_libraries(${CIFPP_TEST} PRIVATE cifpp::cifpp Catch2::Catch2)
 	target_include_directories(${CIFPP_TEST} PRIVATE "${EIGEN_INCLUDE_DIR}")
+	target_compile_features(${CIFPP_TEST} PUBLIC cxx_std_23)
 
 	if(MSVC)
 		# Specify unwind semantics so that MSVC knowns how to handle exceptions
 		target_compile_options(${CIFPP_TEST} PRIVATE /EHsc)
 	endif()
 
-	add_custom_target(
-		"run-${CIFPP_TEST}"
-		DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/Run${CIFPP_TEST}.touch ${CIFPP_TEST})
-
-	add_custom_command(
-		OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/Run${CIFPP_TEST}.touch
-		COMMAND $<TARGET_FILE:${CIFPP_TEST}> --data-dir
-		${CMAKE_CURRENT_SOURCE_DIR})
-
-	add_test(NAME ${CIFPP_TEST} COMMAND $<TARGET_FILE:${CIFPP_TEST}> --data-dir
-		${CMAKE_CURRENT_SOURCE_DIR})
-endforeach()
+	if(NOT (CIFPP_TEST STREQUAL "spinner-test"))
+		add_test(NAME ${CIFPP_TEST}
+			COMMAND $<TARGET_FILE:${CIFPP_TEST}> --data-dir ${CMAKE_CURRENT_SOURCE_DIR})
+	endif()
+endforeach()

test/cql-test.cpp

@@ -0,0 +1,570 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2025 NKI/AVL, Netherlands Cancer Institute
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "test-main.hpp"
+
+#include <catch2/catch_test_macros.hpp>
+#include <cif++/cif++.hpp>
+#include <cif++/cql.hpp>
+
+// --------------------------------------------------------------------
+
+cif::file operator""_cf(const char *text, std::size_t length)
+{
+	struct membuf : public std::streambuf
+	{
+		membuf(char *text, std::size_t length)
+		{
+			this->setg(text, text, text + length);
+		}
+	} buffer(const_cast<char *>(text), length);
+
+	std::istream is(&buffer);
+	return cif::file(is);
+}
+
+// --------------------------------------------------------------------
+
+const char *kAuthors[] = {
+	"Kleywegt, G.J.",
+	"Bergfors, T.",
+	"Senn, H.",
+	"Le Motte, P.",
+	"Gsell, B.",
+	"Shudo, K.",
+	"Jones, T.A.",
+
+	"Banaszak, L.",
+	"Winter, N.",
+	"Xu, Z.",
+	"Bernlohr, D.A.",
+	"Cowan, S.W.",
+	"Jones, T.A.",
+	"Bergfors, T.",
+	"Kleywegt, G.J.",
+	"Jones, T.A.",
+	"Cowan, S.W.",
+	"Newcomer, M.E.",
+	"Jones, T.A.",
+	"Jones, T.A.",
+	"Bergfors, T.",
+	"Sedzik, J.",
+	"Unge, T."
+};
+
+// Test simple SELECT
+TEST_CASE("cql-1")
+{
+	cif::file f(gTestDir / ".." / "examples" / "1cbs.cif.gz");
+	auto &db = f.front();
+	db.load_dictionary("mmcif_pdbx.dic");
+
+	cif::cql::connection connection(db);
+	cif::cql::transaction tx(connection);
+
+	auto r = tx.exec("SELECT name, ordinal FROM citation_author WHERE citation_id = 'primary';");
+	CHECK(r.size() == 7);
+
+	for (size_t ix = 0; auto row : r)
+	{
+		REQUIRE(ix < (sizeof(kAuthors) / sizeof(char *)));
+
+		CHECK(row[0].get<std::string>() == kAuthors[ix]);
+		CHECK(row[1].get<size_t>() == ix + 1);
+
+		CHECK(row["name"].get<std::string>() == kAuthors[ix]);
+		CHECK(row["ordinal"].get<size_t>() == ix + 1);
+
+		++ix;
+	}
+
+	r = tx.exec("SELECT ordinal, name FROM citation_author WHERE citation_id = 'primary';");
+	CHECK(r.size() == 7);
+
+	for (size_t ix = 0; auto row : r)
+	{
+		REQUIRE(ix < (sizeof(kAuthors) / sizeof(char *)));
+
+		CHECK(row[1].get<std::string>() == kAuthors[ix]);
+		CHECK(row[0].get<size_t>() == ix + 1);
+
+		CHECK(row["name"].get<std::string>() == kAuthors[ix]);
+		CHECK(row["ordinal"].get<size_t>() == ix + 1);
+
+		++ix;
+	}
+
+	r = tx.exec("SELECT * FROM citation_author WHERE citation_id = 'primary';");
+	CHECK(r.size() == 7);
+
+	for (int ix = 0; auto row : r)
+	{
+		REQUIRE(static_cast<size_t>(ix) < (sizeof(kAuthors) / sizeof(char *)));
+
+		for (auto fld : row)
+		{
+			switch (fld.num())
+			{
+				case 0:
+					CHECK(fld.name() == "citation_id");
+					CHECK(fld.get<std::string>() == "primary");
+					break;
+				case 1:
+					CHECK(fld.name() == "name");
+					CHECK(fld.get<std::string>() == kAuthors[ix]);
+					break;
+				case 2:
+					CHECK(fld.name() == "ordinal");
+					CHECK(fld.get<int>() == ix + 1);
+					break;
+				default:
+					CHECK(fld.name() == "identifier_ORCID");
+					CHECK(fld.is_null());
+					break;
+			}
+		}
+
+		CHECK(row["name"].get<std::string>() == kAuthors[ix]);
+		CHECK(row["ordinal"].get<int>() == ix + 1);
+		CHECK(row["citation_id"].get<std::string>() == "primary");
+
+		++ix;
+	}
+}
+
+// Test SELECT AS
+TEST_CASE("cql-2")
+{
+	cif::file f(gTestDir / ".." / "examples" / "1cbs.cif.gz");
+	auto &db = f.front();
+	db.load_dictionary("mmcif_pdbx.dic");
+
+	cif::cql::connection connection(db);
+	cif::cql::transaction tx(connection);
+
+	auto r = tx.exec("SELECT name AS v1, ordinal AS v2 FROM citation_author WHERE citation_id = 'primary';");
+	CHECK(r.size() == 7);
+
+	for (size_t ix = 0; auto row : r)
+	{
+		REQUIRE(ix < (sizeof(kAuthors) / sizeof(char *)));
+
+		CHECK(row[0].get<std::string>() == kAuthors[ix]);
+		CHECK(row[1].get<size_t>() == ix + 1);
+
+		CHECK(row["v1"].get<std::string>() == kAuthors[ix]);
+		CHECK(row["v2"].get<size_t>() == ix + 1);
+
+		++ix;
+	}
+}
+
+TEST_CASE("cql-3")
+{
+	cif::file f(gTestDir / ".." / "examples" / "1cbs.cif.gz");
+	auto &db = f.front();
+	db.load_dictionary("mmcif_pdbx.dic");
+
+	cif::cql::connection connection(db);
+	cif::cql::transaction tx(connection);
+
+	auto r = tx.exec("SELECT name FROM citation_author WHERE ordinal = 10").one_field();
+	CHECK(r.get<std::string>() == kAuthors[9]);
+}
+
+TEST_CASE("cql-4")
+{
+	cif::file f(gTestDir / ".." / "examples" / "1cbs.cif.gz");
+	auto &db = f.front();
+	db.load_dictionary("mmcif_pdbx.dic");
+
+	cif::cql::connection connection(db);
+	cif::cql::transaction tx(connection);
+
+	auto r = tx.exec("SELECT name FROM citation_author WHERE ordinal BETWEEN 10 AND 15");
+	REQUIRE(r.size() == 6);
+}
+
+TEST_CASE("cql-5")
+{
+	cif::file f(gTestDir / ".." / "examples" / "1cbs.cif.gz");
+	auto &db = f.front();
+	db.load_dictionary("mmcif_pdbx.dic");
+
+	cif::cql::connection connection(db);
+	cif::cql::transaction tx(connection);
+
+	auto r = tx.exec("SELECT (SELECT year FROM citation WHERE id = citation_id) AS jaar FROM citation_author WHERE ordinal IS 23").one_field();
+	CHECK(r.name() == "jaar");
+	CHECK(r.get<int>() == 1988);
+}
+
+TEST_CASE("cql-6")
+{
+	cif::file f(gTestDir / ".." / "examples" / "1cbs.cif.gz");
+	auto &db = f.front();
+	db.load_dictionary("mmcif_pdbx.dic");
+
+	cif::cql::connection connection(db);
+	cif::cql::transaction tx(connection);
+
+	auto r = tx.exec("SELECT COUNT(*) FROM citation WHERE page_last IS NULL").one_field();
+	CHECK(r.get<int>() == 4);
+
+	r = tx.exec("SELECT COUNT(*) FROM citation WHERE page_last IS NOT NULL").one_field();
+	CHECK(r.get<int>() == 1);
+}
+
+TEST_CASE("cql-stream-1")
+{
+	cif::file f(gTestDir / ".." / "examples" / "1cbs.cif.gz");
+	auto &db = f.front();
+	db.load_dictionary("mmcif_pdbx.dic");
+
+	cif::cql::connection connection(db);
+	cif::cql::transaction tx(connection);
+
+	for (size_t ix = 0;
+		const auto &[name, ordinal] : tx.stream<std::string, size_t>(
+			"SELECT name, ordinal FROM citation_author WHERE citation_id = 'primary';"))
+	{
+		REQUIRE(ix < (sizeof(kAuthors) / sizeof(char *)));
+
+		CHECK(name == kAuthors[ix]);
+		CHECK(ordinal == (ix + 1));
+
+		++ix;
+	}
+}
+
+// --------------------------------------------------------------------
+
+TEST_CASE("cql-insert-1")
+{
+	auto f1 = R"(
+data_T1
+loop_
+_table1.id
+_table1.name
+1 aap
+2 noot)"_cf;
+	auto f0 = f1;
+
+	auto &db = f1.front();
+
+	cif::cql::connection connection(db);
+	cif::cql::transaction tx(connection);
+
+	auto count = tx.exec("SELECT COUNT(*) FROM table1;").one_field().get<int>();
+	CHECK(count == 2);
+
+	auto r = tx.exec("INSERT INTO table1 (id, name) VALUES (3, 'mies')");
+
+	count = tx.exec("SELECT COUNT(*) FROM table1").one_field().get<int>();
+	CHECK(count == 3);
+
+	(void)tx.exec("DELETE FROM table1 WHERE CAST(id AS INTEGER) = 1;");
+
+	count = tx.exec("SELECT COUNT(*) FROM table1;").one_field().get<int>();
+	CHECK(count == 2);
+
+	(void)tx.exec("UPDATE table1 SET name = 'amandel' WHERE CAST(id AS INTEGER) = 2");
+
+	auto f2 = R"(
+data_T1
+loop_
+_table1.id
+_table1.name
+2 amandel
+3 mies)"_cf;
+
+	CHECK(f1 == f2);
+
+	tx.rollback();
+
+	CHECK(f1 == f0);
+}
+
+// --------------------------------------------------------------------
+
+TEST_CASE("cql-rename")
+{
+	auto f1 = R"(
+data_T1
+loop_
+_table1.id
+_table1.name
+1 aap
+2 noot)"_cf;
+
+	auto &db = f1.front();
+
+	cif::cql::connection connection(db);
+	cif::cql::transaction tx(connection);
+
+	(void)tx.exec("ALTER TABLE table1 RENAME TO 'table2'");
+
+	auto f2 = R"(
+data_T1
+loop_
+_table2.id
+_table2.name
+1 aap
+2 noot)"_cf;
+
+	CHECK(f1 == f2);
+}
+
+// --------------------------------------------------------------------
+
+TEST_CASE("cql-foreign-keys-1")
+{
+	const char dict[] = R"(
+data_test_dict.dic
+    _datablock.id	test_dict.dic
+    _datablock.description
+;
+    A test dictionary
+;
+    _dictionary.title           test_dict.dic
+    _dictionary.datablock_id    test_dict.dic
+    _dictionary.version         1.0
+
+     loop_
+    _item_type_list.code
+    _item_type_list.primitive_code
+    _item_type_list.construct
+    _item_type_list.detail
+               code      char
+               '[][_,.;:"&<>()/\{}'`~!@#$%A-Za-z0-9*|+-]*'
+;              code item types/single words ...
+;
+               text      char
+               '[][ \n\t()_,.;:"&<>/\{}'`~!@#$%?+=*A-Za-z0-9|^-]*'
+;              text item types / multi-line text ...
+;
+               int       numb
+               '[+-]?[0-9]+'
+;              int item types are the subset of numbers that are the negative
+               or positive integers.
+;
+
+save_cat_1
+    _category.description     'A simple test category'
+    _category.id              cat_1
+    _category.mandatory_code  no
+    _category_key.name        '_cat_1.id'
+
+    save_
+
+save__cat_1.id
+    _item.name                '_cat_1.id'
+    _item.category_id         cat_1
+    _item.mandatory_code      yes
+    _item_aliases.dictionary  cif_core.dic
+    _item_aliases.version     2.0.1
+    _item_linked.child_name   '_cat_2.parent_id'
+    _item_linked.parent_name  '_cat_1.id'
+    _item_type.code           code
+    save_
+
+save__cat_1.name
+    _item.name                '_cat_1.name'
+    _item.category_id         cat_1
+    _item.mandatory_code      yes
+    _item_aliases.dictionary  cif_core.dic
+    _item_aliases.version     2.0.1
+    _item_type.code           text
+    save_
+
+save_cat_2
+    _category.description     'A second simple test category'
+    _category.id              cat_2
+    _category.mandatory_code  no
+    _category_key.name        '_cat_2.id'
+    save_
+
+save__cat_2.id
+    _item.name                '_cat_2.id'
+    _item.category_id         cat_2
+    _item.mandatory_code      yes
+    _item_aliases.dictionary  cif_core.dic
+    _item_aliases.version     2.0.1
+    _item_type.code           int
+    save_
+
+save__cat_2.parent_id
+    _item.name                '_cat_2.parent_id'
+    _item.category_id         cat_2
+    _item.mandatory_code      yes
+    _item_aliases.dictionary  cif_core.dic
+    _item_aliases.version     2.0.1
+    _item_type.code           code
+    save_
+
+save__cat_2.desc
+    _item.name                '_cat_2.desc'
+    _item.category_id         cat_2
+    _item.mandatory_code      yes
+    _item_aliases.dictionary  cif_core.dic
+    _item_aliases.version     2.0.1
+    _item_type.code           text
+    save_
+    )";
+
+	struct membuf : public std::streambuf
+	{
+		membuf(char *text, std::size_t length)
+		{
+			this->setg(text, text, text + length);
+		}
+	} buffer(const_cast<char *>(dict), sizeof(dict) - 1);
+
+	std::istream is_dict(&buffer);
+
+	cif::validator validator(is_dict);
+
+	cif::file f;
+
+	// --------------------------------------------------------------------
+
+	const char data[] = R"(
+data_test
+loop_
+_cat_1.id
+_cat_1.name
+1 Aap
+2 Noot
+3 Mies
+
+loop_
+_cat_2.id
+_cat_2.parent_id
+_cat_2.desc
+1 1 'Een dier'
+2 1 'Een andere aap'
+3 2 'walnoot bijvoorbeeld'
+    )";
+
+	struct data_membuf : public std::streambuf
+	{
+		data_membuf(char *text, std::size_t length)
+		{
+			this->setg(text, text, text + length);
+		}
+	} data_buffer(const_cast<char *>(data), sizeof(data) - 1);
+
+	std::istream is_data(&data_buffer);
+	f.load(is_data);
+	f.front().set_validator(&validator);
+
+	auto &db = f.front();
+
+	SECTION("stream")
+	{
+		cif::cql::connection connection(db);
+		cif::cql::transaction tx(connection);
+
+		for (const auto &desc : tx.stream<std::string>(R"(SELECT b.desc FROM cat_1 a, cat_2 b WHERE a.id = b.parent_id AND a.name = 'Noot')"))
+		{
+			CHECK(desc == "walnoot bijvoorbeeld");
+		}
+	}
+
+	// Check cascading delete
+	SECTION("delete")
+	{
+		cif::cql::connection connection(db);
+		cif::cql::transaction tx(connection);
+
+		tx.exec("DELETE FROM cat_1 WHERE id = 1");
+		CHECK(db["cat_1"].size() == 2);
+		CHECK(db["cat_2"].size() == 1);
+
+		tx.rollback();
+		CHECK(db["cat_1"].size() == 3);
+		CHECK(db["cat_2"].size() == 3);
+	}
+
+	// Check cascading update
+	SECTION("update")
+	{
+		cif::cql::connection connection(db);
+		cif::cql::transaction tx(connection);
+
+		tx.exec("UPDATE cat_1 SET id = '4' WHERE id = '1'");
+		CHECK(db["cat_1"].size() == 3);
+		CHECK(db["cat_2"].size() == 3);
+		CHECK(db["cat_1"].count(cif::key("id") == 4) == 1);
+		CHECK(db["cat_2"].count(cif::key("parent_id") == 4) == 2);
+
+		std::cout << db;
+
+		tx.rollback();
+		CHECK(db["cat_1"].size() == 3);
+		CHECK(db["cat_2"].size() == 3);
+		CHECK_FALSE(db["cat_1"].contains(cif::key("id") == 4));
+		CHECK_FALSE(db["cat_2"].contains(cif::key("parent_id") == 4));
+
+		std::cout << db;
+	}
+}
+
+// --------------------------------------------------------------------
+
+TEST_CASE("drop-table")
+{
+	auto f1 = R"(
+data_T1
+loop_
+_table1.id
+_table1.name
+1 aap
+2 noot)"_cf;
+
+	auto &db = f1.front();
+
+	cif::cql::connection connection(db);
+	cif::cql::transaction tx(connection);
+
+	SECTION("commit")
+	{
+		(void)tx.exec("DROP TABLE table1;");
+		tx.commit();
+
+		CHECK(db.empty());
+	}
+
+	// Ah, too bad: this doesn't work
+	// SECTION("rollback")
+	// {
+	// 	(void)tx.exec("DROP TABLE table1;");
+	// 	tx.rollback();
+
+	// 	CHECK(not db.empty());
+	// 	CHECK(db["table1"].size() == 2);
+	// }
+}

test/io-test.cpp

@@ -1,4 +1,30 @@
-#include <cif++.hpp>
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ * 
+ * Copyright (c) 2026 NKI/AVL, Netherlands Cancer Institute
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <cif++/cif++.hpp>
 
 class dummy_parser : public cif::sac_parser
 {

test/matrix-test.cpp

@@ -0,0 +1,115 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2025 NKI/AVL, Netherlands Cancer Institute
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "cif++/matrix.hpp"
+#include "test-main.hpp"
+
+#include <catch2/catch_test_macros.hpp>
+#include <cif++/cif++.hpp>
+
+TEST_CASE("m1")
+{
+	cif::matrix3x3<int> m = cif::identity_matrix<int>(3);
+
+	CHECK(cif::determinant(m) == 1);
+}
+
+TEST_CASE("m2")
+{
+	cif::matrix4x4<int> m = cif::identity_matrix<int>(4);
+
+	cif::sub_matrix<cif::matrix4x4<int>> ms(m, 1, 1);
+	CHECK(ms == cif::identity_matrix<int>(3));
+}
+
+TEST_CASE("m3")
+{
+	cif::matrix4x4<int> m{
+		{ 1, 2, 3, 4,      //
+			5, 6, 7, 8,    //
+			9, 10, 11, 12, //
+			13, 14, 15, 16 }
+	};
+	cif::sub_matrix<cif::matrix4x4<int>> ms(m, 1, 1);
+
+	cif::matrix3x3<int> t{
+		{ 1, 3, 4, 9, 11, 12, 13, 15, 16 }
+	};
+
+	CHECK(ms == t);
+}
+
+TEST_CASE("m4")
+{
+	cif::matrix4x4<int> m{
+		{
+			-2,
+			3,
+			1,
+			0,
+			4,
+			1,
+			-3,
+			2,
+			0,
+			-1,
+			2,
+			5,
+			3,
+			2,
+			0,
+			-4,
+		}
+	};
+
+	std::cout << m << "\n\n";
+
+	// std::cout << cif::matrix3x3<int>(cif::sub_matrix<decltype(m)>(m, 0, 0)) << "\n\n";
+	// std::cout << cif::matrix3x3<int>(cif::sub_matrix<decltype(m)>(m, 0, 1)) << "\n\n";
+	// std::cout << cif::matrix3x3<int>(cif::sub_matrix<decltype(m)>(m, 0, 2)) << "\n\n";
+	// std::cout << cif::matrix3x3<int>(cif::sub_matrix<decltype(m)>(m, 0, 3)) << "\n\n";
+
+	// std::cout << cif::determinant(cif::matrix3x3<int>(cif::sub_matrix<decltype(m)>(m, 0, 0))) << "\n\n";
+	// std::cout << cif::determinant(cif::matrix3x3<int>(cif::sub_matrix<decltype(m)>(m, 0, 1))) << "\n\n";
+	// std::cout << cif::determinant(cif::matrix3x3<int>(cif::sub_matrix<decltype(m)>(m, 0, 2))) << "\n\n";
+	// std::cout << cif::determinant(cif::matrix3x3<int>(cif::sub_matrix<decltype(m)>(m, 0, 3))) << "\n\n";
+
+	CHECK(cif::determinant(m) == 332);
+}
+
+// --------------------------------------------------------------------
+
+TEST_CASE("m5")
+{
+    cif::matrix4x4<float> m = cif::identity_matrix<float>(4);
+    cif::matrix_fixed<float, 1, 4> v({ 0, 0.5f, 0, 1.0f });
+
+    auto mv = v * m;
+
+    CHECK(mv == v);
+
+}
+

test/model-test.cpp

@@ -26,9 +26,8 @@
 
 #include "test-main.hpp"
 
-#include <stdexcept>
-
-#include <cif++.hpp>
+#include <catch2/catch_test_macros.hpp>
+#include <cif++/cif++.hpp>
 
 // --------------------------------------------------------------------
 
@@ -54,7 +53,7 @@ TEST_CASE("create_nonpoly_1")
 
 	cif::file file;
 	auto &&[dbi, ignore] = file.emplace("TEST"); // create a datablock
-	dbi->set_validator(&cif::validator_factory::instance().get("mmcif_pdbx.dic"));
+	dbi->load_dictionary("mmcif_pdbx.dic");
 
 	cif::mm::structure structure(file);
 
@@ -82,7 +81,7 @@ _atom_site.pdbx_formal_charge
 # that's enough to test with
 )"_cf;
 
-	atoms.front().set_validator(&cif::validator_factory::instance().get("mmcif_pdbx.dic"));
+	atoms.front().load_dictionary("mmcif_pdbx.dic");
 
 	auto &hem_data = atoms["HEM"];
 	auto &atom_site = hem_data["atom_site"];
@@ -94,8 +93,7 @@ _atom_site.pdbx_formal_charge
 
 	structure.create_non_poly(entity_id, atom_data);
 
-	auto expected = R"(
-data_TEST
+	auto expected = R"(data_TEST
 # 
 _pdbx_nonpoly_scheme.asym_id         A 
 _pdbx_nonpoly_scheme.ndb_seq_num     1 
@@ -139,7 +137,7 @@ _chem_comp.id               HEM
 _chem_comp.type             NON-POLYMER
 _chem_comp.name             'PROTOPORPHYRIN IX CONTAINING FE'
 _chem_comp.formula          'C34 H32 Fe N4 O4'
-_chem_comp.formula_weight   616.487000
+_chem_comp.formula_weight   616.487
 #
 _pdbx_entity_nonpoly.entity_id   1
 _pdbx_entity_nonpoly.name        'PROTOPORPHYRIN IX CONTAINING FE'
@@ -148,7 +146,7 @@ _pdbx_entity_nonpoly.comp_id     HEM
 _entity.id                 1
 _entity.type               non-polymer
 _entity.pdbx_description   'PROTOPORPHYRIN IX CONTAINING FE'
-_entity.formula_weight     616.487000
+_entity.formula_weight     616.487
 #
 _struct_asym.id                            A
 _struct_asym.entity_id                     1
@@ -159,14 +157,20 @@ _struct_asym.details                       ?
 _atom_type.symbol   C
 )"_cf;
 
-	expected.front().set_validator(&cif::validator_factory::instance().get("mmcif_pdbx.dic"));
+	expected.front().load_dictionary("mmcif_pdbx.dic");
 
 	if (not(expected.front() == structure.get_datablock()))
 	{
-		std::cerr << expected.front() << '\n'
+		CHECK(false);
+		std::cout << expected << '\n'
 				  << '\n'
 				  << structure.get_datablock() << '\n';
-		REQUIRE(false);
+
+		
+		std::ofstream of("/tmp/a");
+		of << expected;
+
+		file.save("/tmp/b");
 	}
 }
 
@@ -178,7 +182,7 @@ TEST_CASE("create_nonpoly_2")
 
 	cif::file file;
 	auto &&[dbi, ignore] = file.emplace("TEST"); // create a datablock
-	dbi->set_validator(&cif::validator_factory::instance().get("mmcif_pdbx.dic"));
+	dbi->load_dictionary("mmcif_pdbx.dic");
 
 	cif::mm::structure structure(file);
 
@@ -195,9 +199,9 @@ TEST_CASE("create_nonpoly_2")
 			{ "type_symbol", type_symbol },
 			{ "label_atom_id", label_atom_id },
 			{ "auth_atom_id", label_atom_id },
-			{ "Cartn_x", Cartn_x },
-			{ "Cartn_y", Cartn_y },
-			{ "Cartn_z", Cartn_z } });
+			{ "Cartn_x", { Cartn_x, 3 } },
+			{ "Cartn_y", { Cartn_y, 3 } },
+			{ "Cartn_z", { Cartn_z, 3 } } });
 
 		if (atoms.size() == 4)
 			break;
@@ -243,14 +247,14 @@ _atom_site.auth_atom_id
 _atom_site.pdbx_PDB_model_num
 1 A ? A CHA HEM 1 . C HETATM ? 2.748 -19.531 39.896 1.00 ? 1 HEM CHA 1
 2 A ? A CHB HEM 1 . C HETATM ? 3.258 -17.744 35.477 1.00 ? 1 HEM CHB 1
-3 A ? A CHC HEM 1 . C HETATM ? 1.703 -21.9   33.637 1.00 ? 1 HEM CHC 1
+3 A ? A CHC HEM 1 . C HETATM ? 1.703 -21.900 33.637 1.00 ? 1 HEM CHC 1
 4 A ? A CHD HEM 1 . C HETATM ? 1.149 -23.677 38.059 1.00 ? 1 HEM CHD 1
 #
 _chem_comp.id               HEM
 _chem_comp.type             NON-POLYMER
 _chem_comp.name             'PROTOPORPHYRIN IX CONTAINING FE'
 _chem_comp.formula          'C34 H32 Fe N4 O4'
-_chem_comp.formula_weight   616.487000
+_chem_comp.formula_weight   616.487
 #
 _pdbx_entity_nonpoly.entity_id   1
 _pdbx_entity_nonpoly.name        'PROTOPORPHYRIN IX CONTAINING FE'
@@ -259,7 +263,7 @@ _pdbx_entity_nonpoly.comp_id     HEM
 _entity.id                 1
 _entity.type               non-polymer
 _entity.pdbx_description   'PROTOPORPHYRIN IX CONTAINING FE'
-_entity.formula_weight     616.487000
+_entity.formula_weight     616.487
 #
 _struct_asym.id                            A
 _struct_asym.entity_id                     1
@@ -270,13 +274,13 @@ _struct_asym.details                       ?
 _atom_type.symbol   C
 )"_cf;
 
-	expected.front().set_validator(&cif::validator_factory::instance().get("mmcif_pdbx.dic"));
+	expected.front().load_dictionary("mmcif_pdbx.dic");
 
 	REQUIRE(expected.front() == structure.get_datablock());
 
 	if (not(expected.front() == structure.get_datablock()))
 	{
-		// REQUIRE(false);
+		CHECK(false);
 		std::cout << expected.front() << '\n'
 				  << '\n'
 				  << structure.get_datablock() << '\n';
@@ -354,14 +358,14 @@ _struct_asym.details                       ?
 #
 )"_cf;
 
-	data.front().set_validator(&cif::validator_factory::instance().get("mmcif_pdbx.dic"));
+	data.front().load_dictionary("mmcif_pdbx.dic");
 
 	cif::mm::structure s(data);
 
-	REQUIRE(s.get_atom_by_id("1").get_label_atom_id() == "CHA");
-	REQUIRE(s.get_atom_by_id("2").get_label_atom_id() == "CHC");
-	REQUIRE(s.get_atom_by_id("3").get_label_atom_id() == "CHB");
-	REQUIRE(s.get_atom_by_id("4").get_label_atom_id() == "CHD");
+	CHECK(s.get_atom_by_id("1").get_label_atom_id() == "CHA");
+	CHECK(s.get_atom_by_id("2").get_label_atom_id() == "CHC");
+	CHECK(s.get_atom_by_id("3").get_label_atom_id() == "CHB");
+	CHECK(s.get_atom_by_id("4").get_label_atom_id() == "CHD");
 }
 
 // --------------------------------------------------------------------
@@ -382,19 +386,19 @@ TEST_CASE("atom_numbers_1")
 	{
 		auto atom = structure.get_atom_by_id(id);
 
-		REQUIRE(atom.get_label_asym_id() == label_asym_id);
-		REQUIRE(atom.get_label_seq_id() == label_seq_id);
-		REQUIRE(atom.get_label_atom_id() == label_atom_id);
-		REQUIRE(atom.get_auth_seq_id() == auth_seq_id);
-		REQUIRE(atom.get_label_comp_id() == label_comp_id);
+		CHECK(atom.get_label_asym_id() == label_asym_id);
+		CHECK(atom.get_label_seq_id() == label_seq_id);
+		CHECK(atom.get_label_atom_id() == label_atom_id);
+		CHECK(atom.get_auth_seq_id() == auth_seq_id);
+		CHECK(atom.get_label_comp_id() == label_comp_id);
 
-		REQUIRE(ai != atoms.end());
+		CHECK(ai != atoms.end());
 
-		REQUIRE(ai->id() == id);
+		CHECK(ai->id() == id);
 		++ai;
 	}
 
-	REQUIRE(ai == atoms.end());
+	CHECK(ai == atoms.end());
 }
 // --------------------------------------------------------------------
 
@@ -414,9 +418,7 @@ TEST_CASE("test_load_2")
 	auto &pdbx_poly_seq_scheme = db["pdbx_poly_seq_scheme"];
 
 	for (auto &poly : s.polymers())
-	{
-		REQUIRE(poly.size() == pdbx_poly_seq_scheme.find("asym_id"_key == poly.get_asym_id()).size());
-	}
+		CHECK(poly.size() == pdbx_poly_seq_scheme.find("asym_id"_key == poly.get_asym_id()).size());
 }
 
 TEST_CASE("remove_residue_1")
@@ -429,7 +431,22 @@ TEST_CASE("remove_residue_1")
 	cif::mm::structure s(file);
 	s.remove_residue(s.get_residue("B"));
 
-	REQUIRE_NOTHROW(s.validate_atoms());
+	CHECK_NOTHROW(s.validate_atoms());
+}
+
+// --------------------------------------------------------------------
+
+TEST_CASE("test_alternates_1")
+{
+	using namespace cif::literals;
+
+	const std::filesystem::path example(gTestDir / ".." / "examples" / "1cbs.cif.gz");
+	cif::file file(example.string());
+
+	cif::mm::structure s(file);
+
+	for (auto atom : s.atoms())
+		CHECK_FALSE(atom.is_alternate());
 }
 
 // --------------------------------------------------------------------
@@ -566,7 +583,7 @@ _struct_asym.details                       ?
 #
 )"_cf;
 
-	data.front().set_validator(&cif::validator_factory::instance().get("mmcif_pdbx.dic"));
+	data.front().load_dictionary("mmcif_pdbx.dic");
 
 	SECTION("max")
 	{

test/query-test.cpp

@@ -26,7 +26,7 @@
 
 #include "test-main.hpp"
 
-#include <cif++.hpp>
+#include <cif++/cif++.hpp>
 
 #include <iostream>
 #include <fstream>
@@ -49,6 +49,4 @@ TEST_CASE("q-1")
 
 		CHECK(pdbx_poly_seq_scheme.count("asym_id"_key == "A" and "entity_id"_key == 1 and "seq_id"_key == 1 and "mon_id"_key == "PRO" and "hetero"_key == false) == 1);
 	}
-	
-
 }

test/reconstruction-test.cpp

@@ -24,15 +24,19 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "cif++/utilities.hpp"
 #include "test-main.hpp"
 
-#include <cif++.hpp>
+#include <cif++/cif++.hpp>
 
+#include <filesystem>
 #include <iostream>
 #include <fstream>
 
 TEST_CASE("reconstruct")
 {
+	cif::VERBOSE = 1;
+
 	cif::compound_factory::instance().push_dictionary(gTestDir / "REA.cif");
 
 	for (std::filesystem::directory_iterator i(gTestDir / "reconstruct"); i != std::filesystem::directory_iterator{}; ++i)
@@ -54,9 +58,18 @@ TEST_CASE("reconstruct")
 
 			std::error_code ec;
 			CHECK_FALSE(cif::pdb::is_valid_pdbx_file(f, ec));
-			CHECK((bool)ec);
+			CHECK(ec != std::errc{});
 
-			CHECK(cif::pdb::reconstruct_pdbx(f));
+			auto valid = cif::pdb::reconstruct_pdbx(f);
+
+			CHECK(valid);
+
+			if (not valid)
+			{
+				std::ofstream of(std::filesystem::temp_directory_path() / i->path().filename());
+				of << f;
+				of.close();
+			}
 		}
 	}
 }

test/rename-compound-test.cpp

@@ -26,7 +26,7 @@
 
 #include "test-main.hpp"
 
-#include <cif++.hpp>
+#include <cif++/cif++.hpp>
 
 #include <iostream>
 #include <fstream>

test/sugar-test.cpp

@@ -28,7 +28,7 @@
 
 #include <stdexcept>
 
-#include <cif++.hpp>
+#include <cif++/cif++.hpp>
 
 // --------------------------------------------------------------------
 
@@ -183,4 +183,6 @@ TEST_CASE("delete_sugar_1")
 	// file.save(gTestDir / "test-create_sugar_3.cif");
 
 	cif::mm::structure s2(file);
+
+	file.save("/tmp/min-s.cif");
 }

test/test-main.cpp

@@ -1,22 +1,46 @@
-#define CATCH_CONFIG_RUNNER 1
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ * 
+ * Copyright (c) 2026 NKI/AVL, Netherlands Cancer Institute
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define CATCH_CONFIG_RUNNER 1 // NOLINT
 
 #include "test-main.hpp"
 
-#include <cif++.hpp>
+#include <cif++/utilities.hpp>
+#include <cif++/compound.hpp>
 
-std::filesystem::path gTestDir = std::filesystem::current_path();
+std::filesystem::path gTestDir;
 
 int main(int argc, char *argv[])
 {
+	gTestDir = std::filesystem::current_path();
+
 	Catch::Session session; // There must be exactly one instance
 
 	// Build a new parser on top of Catch2's
-#if CATCH22
-	using namespace Catch::clara;
-#else
-	// Build a new parser on top of Catch2's
 	using namespace Catch::Clara;
-#endif
 
 	auto cli = session.cli()                               // Get Catch2's command line parser
 	           | Opt(gTestDir, "data-dir")                 // bind variable to a new option, with a hint string

test/test-main.hpp

@@ -1,17 +1,17 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause
- * 
+ *
  * Copyright (c) 2024 NKI/AVL, Netherlands Cancer Institute
- * 
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
- * 
+ *
  * 1. Redistributions of source code must retain the above copyright notice, this
  *    list of conditions and the following disclaimer
  * 2. Redistributions in binary form must reproduce the above copyright notice,
  *    this list of conditions and the following disclaimer in the documentation
  *    and/or other materials provided with the distribution.
- * 
+ *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
@@ -26,11 +26,7 @@
 
 #pragma once
 
-#if CATCH22
-#include <catch2/catch.hpp>
-#else
 #include <catch2/catch_all.hpp>
-#endif
 
 #include <filesystem>
 

test/unit-3d-test.cpp

@@ -24,13 +24,19 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "cif++/cif++.hpp"
+#include "cif++/symmetry.hpp"
 #include "test-main.hpp"
 
-#include <stdexcept>
+#include <catch2/catch_test_macros.hpp>
+#include <catch2/matchers/catch_matchers_floating_point.hpp>
 
-#include <cif++.hpp>
+#if defined(_MSC_VER)
+# pragma warning(disable : 5054) // warning C5054: operator '&': deprecated between enumerations of different types
+# pragma warning(disable : 4127) // conditional expression is constant
+#endif
 
-#include <Eigen/Eigenvalues>
+#include <Eigen/Eigen>
 
 // --------------------------------------------------------------------
 
@@ -112,7 +118,7 @@ TEST_CASE("t2")
 
 	cif::point xp = cif::cross_product(p[1] - p[0], p[2] - p[0]);
 
-	auto q = cif::construct_from_angle_axis(45, xp); // mmcif::Normalize(Quaternion{45 * mmcif::kPI / 180, xp.mX, xp.mY, xp.mZ});
+	auto q = cif::construct_from_angle_axis(45, xp);
 
 	auto &&[angle, axis] = cif::quaternion_to_angle_axis(q);
 
@@ -129,7 +135,7 @@ TEST_CASE("t3")
 
 	cif::point xp = cif::cross_product(p[1] - p[0], p[2] - p[0]);
 
-	auto q = cif::construct_from_angle_axis(45, xp); // mmcif::Normalize(Quaternion{45 * mmcif::kPI / 180, xp.mX, xp.mY, xp.mZ});
+	auto q = cif::construct_from_angle_axis(45, xp);
 
 	auto v = p[1];
 	v -= p[0];
@@ -224,168 +230,31 @@ TEST_CASE("dh_q_1")
 	}
 }
 
-// --------------------------------------------------------------------
-
-// TEST_CASE("m2q_0")
+// TEST_CASE("m2q_1")
 // {
 // 	for (std::size_t i = 0; i < cif::kSymopNrTableSize; ++i)
 // 	{
 // 		auto d = cif::kSymopNrTable[i].symop().data();
 
-// 		cif::matrix3x3<float> rot;
-// 		float Qxx = rot(0, 0) = d[0];
-// 		float Qxy = rot(0, 1) = d[1];
-// 		float Qxz = rot(0, 2) = d[2];
-// 		float Qyx = rot(1, 0) = d[3];
-// 		float Qyy = rot(1, 1) = d[4];
-// 		float Qyz = rot(1, 2) = d[5];
-// 		float Qzx = rot(2, 0) = d[6];
-// 		float Qzy = rot(2, 1) = d[7];
-// 		float Qzz = rot(2, 2) = d[8];
+// 		Eigen::Matrix3f rot;
 
-// 		Eigen::Matrix4f em;
+// 		rot << d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], d[8];
 
-// 		em << Qxx - Qyy - Qzz, Qyx + Qxy, Qzx + Qxz, Qzy - Qyz,
-// 			Qyx + Qxy, Qyy - Qxx - Qzz, Qzy + Qyz, Qxz - Qzx,
-// 			Qzx + Qxz, Qzy + Qyz, Qzz - Qxx - Qyy, Qyx - Qxy,
-// 			Qzy - Qyz, Qxz - Qzx, Qyx - Qxy, Qxx + Qyy + Qzz;
-
-// 		Eigen::EigenSolver<Eigen::Matrix4f> es(em / 3);
-
-// 		auto ev = es.eigenvalues();
-
-// 		std::size_t bestJ = 0;
-// 		float bestEV = -1;
-
-// 		for (std::size_t j = 0; j < 4; ++j)
+// 		if (rot * rot.transpose() == Eigen::Matrix3f::Identity() and rot.determinant() == 1)
 // 		{
-// 			if (bestEV < ev[j].real())
-// 			{
-// 				bestEV = ev[j].real();
-// 				bestJ = j;
-// 			}
+// 			Eigen::Quaternionf qe(rot);
+// 			auto q = normalize(cif::quaternion{ qe.w(), qe.x(), qe.y(), qe.z() });
+
+// 			cif::point p1{ 1, 1, 1 };
+// 			cif::point p2 = p1;
+// 			p2.rotate(q);
+
+// 			auto p3 = rot * Eigen::Vector3f{ p1.m_x, p1.m_y, p1.m_z };
+
+// 			CHECK_THAT(p2.m_x, Catch::Matchers::WithinRel(p3[0], 0.01f));
+// 			CHECK_THAT(p2.m_y, Catch::Matchers::WithinRel(p3[1], 0.01f));
+// 			CHECK_THAT(p2.m_z, Catch::Matchers::WithinRel(p3[2], 0.01f));
 // 		}
-
-// 		if (std::abs(bestEV - 1) > 0.01)
-// 			continue; // not a rotation matrix
-
-// 		auto col = es.eigenvectors().col(bestJ);
-
-// 		auto q = normalize(cif::quaternion{
-// 			static_cast<float>(col(3).real()),
-// 			static_cast<float>(col(0).real()),
-// 			static_cast<float>(col(1).real()),
-// 			static_cast<float>(col(2).real()) });
-
-// 		cif::point p1{ 1, 1, 1 };
-// 		cif::point p2 = p1;
-// 		p2.rotate(q);
-
-// 		cif::point p3 = rot * p1;
-
-// 		CHECK_THAT(p2.m_x, Catch::Matchers::WithinRel(p3.m_x, 0.01f));
-// 		CHECK_THAT(p2.m_y, Catch::Matchers::WithinRel(p3.m_y, 0.01f));
-// 		CHECK_THAT(p2.m_z, Catch::Matchers::WithinRel(p3.m_z, 0.01f));
-// 	}
-// }
-
-TEST_CASE("m2q_0a")
-{
-	for (std::size_t i = 0; i < cif::kSymopNrTableSize; ++i)
-	{
-		auto d = cif::kSymopNrTable[i].symop().data();
-
-		Eigen::Matrix3f rot;
-		rot << d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], d[8];
-
-		// check to see if this matrix contains a true rotation
-		if (rot * rot.transpose() != Eigen::Matrix3f::Identity() or rot.determinant() != 1)
-			continue;
-
-		Eigen::Quaternionf qe(rot);
-
-		auto q = normalize(cif::quaternion{ qe.w(), qe.x(), qe.y(), qe.z() });
-
-		cif::point p1{ 1, 1, 1 };
-		cif::point p2 = p1;
-		p2.rotate(q);
-
-		cif::matrix3x3<float> rot_c({
-			static_cast<float>(d[0]),
-			static_cast<float>(d[1]),
-			static_cast<float>(d[2]),
-			static_cast<float>(d[3]),
-			static_cast<float>(d[4]),
-			static_cast<float>(d[5]),
-			static_cast<float>(d[6]),
-			static_cast<float>(d[7]),
-			static_cast<float>(d[8])
-		});
-
-		cif::point p3 = rot_c * p1;
-
-		CHECK_THAT(p2.m_x, Catch::Matchers::WithinRel(p3.m_x, 0.01f));
-		CHECK_THAT(p2.m_y, Catch::Matchers::WithinRel(p3.m_y, 0.01f));
-		CHECK_THAT(p2.m_z, Catch::Matchers::WithinRel(p3.m_z, 0.01f));
-	}
-}
-
-// "TEST_CASE(m2q_1")
-// {
-// 	for (std::size_t i = 0; i < cif::kSymopNrTableSize; ++i)
-// 	{
-// 		auto d = cif::kSymopNrTable[i].symop().data();
-
-// 		cif::matrix3x3<float> rot;
-// 		float Qxx = rot(0, 0) = d[0];
-// 		float Qxy = rot(0, 1) = d[1];
-// 		float Qxz = rot(0, 2) = d[2];
-// 		float Qyx = rot(1, 0) = d[3];
-// 		float Qyy = rot(1, 1) = d[4];
-// 		float Qyz = rot(1, 2) = d[5];
-// 		float Qzx = rot(2, 0) = d[6];
-// 		float Qzy = rot(2, 1) = d[7];
-// 		float Qzz = rot(2, 2) = d[8];
-
-// 		cif::matrix4x4<float> m({
-// 			Qxx - Qyy - Qzz, Qyx + Qxy, Qzx + Qxz, Qzy - Qyz,
-// 			Qyx + Qxy, Qyy - Qxx - Qzz, Qzy + Qyz, Qxz - Qzx,
-// 			Qzx + Qxz, Qzy + Qyz, Qzz - Qxx - Qyy, Qyx - Qxy,
-// 			Qzy - Qyz, Qxz - Qzx, Qyx - Qxy, Qxx + Qyy + Qzz
-// 		});
-
-// 		auto &&[ev, em] = cif::eigen(m * (1/3.0f), false);
-
-// 		std::size_t bestJ = 0;
-// 		float bestEV = -1;
-
-// 		for (std::size_t j = 0; j < 4; ++j)
-// 		{
-// 			if (bestEV < ev[j])
-// 			{
-// 				bestEV = ev[j];
-// 				bestJ = j;
-// 			}
-// 		}
-
-// 		if (std::abs(bestEV - 1) > 0.01)
-// 			continue; // not a rotation matrix
-
-// 		auto q = normalize(cif::quaternion{
-// 			static_cast<float>(em(bestJ, 3)),
-// 			static_cast<float>(em(bestJ, 0)),
-// 			static_cast<float>(em(bestJ, 1)),
-// 			static_cast<float>(em(bestJ, 2)) });
-
-// 		cif::point p1{ 1, 1, 1 };
-// 		cif::point p2 = p1;
-// 		p2.rotate(q);
-
-// 		cif::point p3 = rot * p1;
-
-// 		REQUIRE(p2.m_x == p3.m_x);
-// 		REQUIRE(p2.m_y == p3.m_y);
-// 		REQUIRE(p2.m_z == p3.m_z);
 // 	}
 // }
 
@@ -435,11 +304,11 @@ TEST_CASE("symm_4")
 
 	// based on 2b8h
 	auto sg = cif::spacegroup(154); // p 32 2 1
-	auto c = cif::cell(107.516, 107.516, 338.487, 90.00, 90.00, 120.00);
+	auto c = cif::cell(107.516f, 107.516f, 338.487f, 90.00f, 90.00f, 120.00f);
 
-	cif::point a{ -8.688, 79.351, 10.439 };  // O6 NAG A 500
-	cif::point b{ -35.356, 33.693, -3.236 }; // CG2 THR D 400
-	cif::point sb(-6.916, 79.34, 3.236);     // 4_565 copy of b
+	cif::point a{ -8.688f, 79.351f, 10.439f };  // O6 NAG A 500
+	cif::point b{ -35.356f, 33.693f, -3.236f }; // CG2 THR D 400
+	cif::point sb(-6.916f, 79.34f, 3.236f);     // 4_565 copy of b
 
 	CHECK_THAT(distance(a, sg(a, c, "1_455"_symop)), Catch::Matchers::WithinRel(static_cast<float>(c.get_a()), 0.01f));
 	CHECK_THAT(distance(a, sg(a, c, "1_545"_symop)), Catch::Matchers::WithinRel(static_cast<float>(c.get_b()), 0.01f));
@@ -455,37 +324,10 @@ TEST_CASE("symm_4")
 
 // --------------------------------------------------------------------
 
-TEST_CASE("symm_4wvp_1")
-{
-	using namespace cif::literals;
-
-	cif::file f(gTestDir / "4wvp.cif.gz");
-
-	auto &db = f.front();
-	cif::mm::structure s(db);
-
-	cif::crystal c(db);
-
-	cif::point p{ -78.722, 98.528, 11.994 };
-	auto a = s.get_residue("A", 10, "").get_atom_by_atom_id("O");
-
-	auto sp1 = c.symmetry_copy(a.get_location(), "2_565"_symop);
-	CHECK_THAT(sp1.m_x, Catch::Matchers::WithinAbs(p.m_x, 0.5f));
-	CHECK_THAT(sp1.m_y, Catch::Matchers::WithinAbs(p.m_y, 0.5f));
-	CHECK_THAT(sp1.m_z, Catch::Matchers::WithinAbs(p.m_z, 0.5f));
-
-	const auto &[d, sp2, so] = c.closest_symmetry_copy(p, a.get_location());
-
-	REQUIRE(d < 1);
-
-	CHECK_THAT(sp2.m_x, Catch::Matchers::WithinAbs(p.m_x, 0.5f));
-	CHECK_THAT(sp2.m_y, Catch::Matchers::WithinAbs(p.m_y, 0.5f));
-	CHECK_THAT(sp2.m_z, Catch::Matchers::WithinAbs(p.m_z, 0.5f));
-}
-
 TEST_CASE("symm_2bi3_1")
 {
 	cif::file f(gTestDir / "2bi3.cif.gz");
+	f.front().set_validator(cif::validator_factory::instance().get("mmcif_pdbx.dic"));
 
 	auto &db = f.front();
 	cif::mm::structure s(db);
@@ -532,6 +374,7 @@ TEST_CASE("symm_2bi3_1a")
 	using namespace cif::literals;
 
 	cif::file f(gTestDir / "2bi3.cif.gz");
+	f.front().set_validator(cif::validator_factory::instance().get("mmcif_pdbx.dic"));
 
 	auto &db = f.front();
 
@@ -575,6 +418,7 @@ TEST_CASE("symm_2bi3_1a")
 TEST_CASE("symm_3bwh_1")
 {
 	cif::file f(gTestDir / "3bwh.cif.gz");
+	f.front().set_validator(cif::validator_factory::instance().get("mmcif_pdbx.dic"));
 
 	auto &db = f.front();
 
@@ -595,9 +439,100 @@ TEST_CASE("symm_3bwh_1")
 	}
 }
 
+TEST_CASE("symm_476d")
+{
+	cif::file f(gTestDir / "476d.cif.gz");
+	f.front().set_validator(cif::validator_factory::instance().get("mmcif_pdbx.dic"));
+
+	auto &db = f.front();
+	cif::mm::structure s(db);
+
+	cif::crystal c(db);
+
+	auto struct_conn = db["struct_conn"];
+	for (const auto &[asym1, seqid1, authseqid1, atomid1, symm1,
+			 asym2, seqid2, authseqid2, atomid2, symm2,
+			 dist] : struct_conn.find<std::string, int, std::string, std::string, std::string,
+			 std::string, int, std::string, std::string, std::string,
+			 float>(
+			 cif::key("ptnr1_symmetry") != "1_555" or cif::key("ptnr2_symmetry") != "1_555",
+			 "ptnr1_label_asym_id", "ptnr1_label_seq_id", "ptnr1_auth_seq_id", "ptnr1_label_atom_id", "ptnr1_symmetry",
+			 "ptnr2_label_asym_id", "ptnr2_label_seq_id", "ptnr2_auth_seq_id", "ptnr2_label_atom_id", "ptnr2_symmetry",
+			 "pdbx_dist_value"))
+	{
+		auto &r1 = s.get_residue(asym1, seqid1, authseqid1);
+		auto &r2 = s.get_residue(asym2, seqid2, authseqid2);
+
+		auto a1 = r1.get_atom_by_atom_id(atomid1);
+		auto a2 = r2.get_atom_by_atom_id(atomid2);
+
+		auto p1 = a1.get_location();
+		auto p2 = a2.get_location();
+
+		cif::sym_op so1(symm1);
+		cif::sym_op so2(symm2);
+
+		auto sa1 = c.symmetry_copy(p1, so1);
+		auto sa2 = c.symmetry_copy(p2, so2);
+
+		CHECK_THAT(cif::distance(sa1, sa2), Catch::Matchers::WithinAbs(dist, 0.01f));
+	}
+}
+
+TEST_CASE("symm-P_32_2_1_a")
+{
+	cif::cell c{ 80, 80, 120, 90, 90, 120 };
+	cif::spacegroup sg{ 154 };
+
+	cif::crystal crystal{ c, sg };
+
+	cif::point a{ 1, 90, 1 };
+	cif::point p1{ 2, 2, 2 };
+
+	auto d = distance(a, p1);
+
+	auto [d2, p, so] = crystal.closest_symmetry_copy(a, p1);
+
+	std::cout << "d: " << d2 << " p: " << p << " so: " << so.string() << '\n';
+
+	auto p2 = crystal.symmetry_copy(p1, so);
+	auto d3 = distance(p2, a);
+
+	CHECK_THAT(cif::distance(p2, p), Catch::Matchers::WithinAbs(0.f, 0.01f));
+	CHECK_THAT(d3, Catch::Matchers::WithinAbs(d2, 0.01f));
+
+	CHECK(d2 <= d);
+}
+
+TEST_CASE("symm-P_32_2_1")
+{
+	cif::cell c{ 82.162, 82.162, 135.202, 90, 90, 120 };
+	cif::spacegroup sg{ 154 };
+
+	cif::crystal crystal{ c, sg };
+
+	cif::point a{ 1.73727,89.1813,11.1388 };
+	cif::point p1{ -8.98574, 50.3861, -11.6447 };
+
+	auto d = distance(a, p1);
+
+	auto [d2, p, so] = crystal.closest_symmetry_copy(a, p1);
+
+	std::cout << "d: " << d2 << " p: " << p << " so: " << so.string() << '\n';
+
+	auto p2 = crystal.symmetry_copy(p1, so);
+	auto d3 = distance(p2, a);
+
+	CHECK_THAT(cif::distance(p2, p), Catch::Matchers::WithinAbs(0.f, 0.01f));
+	CHECK_THAT(d3, Catch::Matchers::WithinAbs(d2, 0.01f));
+
+	CHECK(d2 <= d);
+}
+
 TEST_CASE("volume_3bwh_1")
 {
 	cif::file f(gTestDir / "1juh.cif.gz");
+	f.front().set_validator(cif::validator_factory::instance().get("mmcif_pdbx.dic"));
 
 	auto &db = f.front();
 
@@ -605,3 +540,40 @@ TEST_CASE("volume_3bwh_1")
 
 	CHECK_THAT(c.get_cell().get_volume(), Catch::Matchers::WithinRel(741009.625f, 0.01f));
 }
+
+// --------------------------------------------------------------------
+
+TEST_CASE("smallest_sphere-1")
+{
+	std::vector<cif::point> pts{
+		{ 0.9295, 4.9006, 46.9706 },
+		{ -0.1215, 5.5936, 46.0726 },
+		{ -0.7975, 4.7046, 45.0796 },
+		{ -1.4875, 3.5486, 45.7196 },
+		{ -0.6535, 2.8816, 46.8186 },
+		{ 0.3825, 3.5156, 47.4496 },
+		{ 1.1995, 2.9206, 48.5286 },
+		{ 0.8255, 2.0466, 49.4716 },
+		{ 1.6625, 1.5036, 50.5176 },
+		{ 1.1165, 0.6056, 51.3626 },
+		{ 1.8325, -0.0064, 52.4656 },
+		{ 1.1945, -0.9044, 53.2216 },
+		{ 1.8135, -1.5534, 54.3566 },
+		{ 1.0925, -2.4574, 55.0656 },
+		{ 1.5205, -3.2204, 56.2476 },
+		{ 1.1955, 5.8066, 48.1796 },
+		{ 2.2495, 4.6896, 46.1796 },
+		{ -1.2515, 1.5186, 47.1786 },
+		{ 3.1385, 1.9106, 50.6166 },
+		{ 3.2605, -1.1834, 54.7206 },
+		{ 2.5975, -3.8554, 56.2096 },
+		{ 0.7975, -3.2184, 57.2686 }
+	};
+
+	for (int i = 0; i < 1000; ++i)
+	{
+		auto [c, r] = cif::smallest_sphere_around_points(pts);
+		CHECK_THAT(cif::distance(c, cif::point{ 0, 0.743099928, 51.1741028 }), Catch::Matchers::WithinAbs(0.f, 0.01f));
+		CHECK_THAT(r, Catch::Matchers::WithinAbs(7.31248331f, 0.01f));
+	}
+}