mirror of
https://github.com/abseil/abseil-cpp.git
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71 lines
2.1 KiB
C++
71 lines
2.1 KiB
C++
// Copyright 2024 The Abseil Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "absl/debugging/internal/utf8_for_code_point.h"
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#include <cstdint>
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#include "absl/base/config.h"
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namespace absl {
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ABSL_NAMESPACE_BEGIN
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namespace debugging_internal {
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namespace {
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// UTF-8 encoding bounds.
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constexpr uint32_t kMinSurrogate = 0xd800, kMaxSurrogate = 0xdfff;
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constexpr uint32_t kMax1ByteCodePoint = 0x7f;
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constexpr uint32_t kMax2ByteCodePoint = 0x7ff;
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constexpr uint32_t kMax3ByteCodePoint = 0xffff;
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constexpr uint32_t kMaxCodePoint = 0x10ffff;
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} // namespace
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Utf8ForCodePoint::Utf8ForCodePoint(uint64_t code_point) {
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if (code_point <= kMax1ByteCodePoint) {
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length = 1;
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bytes[0] = static_cast<char>(code_point);
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return;
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}
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if (code_point <= kMax2ByteCodePoint) {
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length = 2;
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bytes[0] = static_cast<char>(0xc0 | (code_point >> 6));
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bytes[1] = static_cast<char>(0x80 | (code_point & 0x3f));
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return;
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}
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if (kMinSurrogate <= code_point && code_point <= kMaxSurrogate) return;
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if (code_point <= kMax3ByteCodePoint) {
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length = 3;
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bytes[0] = static_cast<char>(0xe0 | (code_point >> 12));
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bytes[1] = static_cast<char>(0x80 | ((code_point >> 6) & 0x3f));
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bytes[2] = static_cast<char>(0x80 | (code_point & 0x3f));
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return;
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}
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if (code_point > kMaxCodePoint) return;
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length = 4;
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bytes[0] = static_cast<char>(0xf0 | (code_point >> 18));
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bytes[1] = static_cast<char>(0x80 | ((code_point >> 12) & 0x3f));
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bytes[2] = static_cast<char>(0x80 | ((code_point >> 6) & 0x3f));
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bytes[3] = static_cast<char>(0x80 | (code_point & 0x3f));
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}
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} // namespace debugging_internal
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ABSL_NAMESPACE_END
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} // namespace absl
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