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// Copyright 2022 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef SRC_TINT_TEXT_UNICODE_H_
#define SRC_TINT_TEXT_UNICODE_H_
#include <cstddef>
#include <cstdint>
#include <string_view>
#include <utility>
namespace tint::text {
/// CodePoint is a unicode code point.
struct CodePoint {
/// Constructor
inline CodePoint() = default;
/// Constructor
/// @param v the code point value
inline explicit CodePoint(uint32_t v) : value(v) {}
/// @returns the code point value
inline operator uint32_t() const { return value; }
/// Assignment operator
/// @param v the new value for the code point
/// @returns this CodePoint
inline CodePoint& operator=(uint32_t v) {
value = v;
return *this;
}
/// @returns true if this CodePoint is in the XID_Start set.
/// @see https://unicode.org/reports/tr31/
bool IsXIDStart() const;
/// @returns true if this CodePoint is in the XID_Continue set.
/// @see https://unicode.org/reports/tr31/
bool IsXIDContinue() const;
/// The code point value
uint32_t value = 0;
};
namespace utf8 {
/// Decodes the first code point in the utf8 string.
/// @param ptr the pointer to the first byte of the utf8 sequence
/// @param len the maximum number of bytes to read
/// @returns a pair of CodePoint and width in code units (bytes).
/// If the next code point cannot be decoded then returns [0,0].
std::pair<CodePoint, size_t> Decode(const uint8_t* ptr, size_t len);
/// Decodes the first code point in the utf8 string.
/// @param utf8_string the string view that contains the utf8 sequence
/// @returns a pair of CodePoint and width in code units (bytes).
/// If the next code point cannot be decoded then returns [0,0].
std::pair<CodePoint, size_t> Decode(std::string_view utf8_string);
/// @returns true if all the utf-8 code points in the string are ASCII
/// (code-points 0x00..0x7f).
bool IsASCII(std::string_view);
} // namespace utf8
} // namespace tint::text
#endif // SRC_TINT_TEXT_UNICODE_H_