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xn65/includes/csharp/text/unicode.hpp
2024-12-13 13:40:51 -03:00

91 lines
3.5 KiB
C++

#ifndef CSHARP_TEXT_UNICODE_HPP
#define CSHARP_TEXT_UNICODE_HPP
#include <cstdint>
#include <vector>
#include "csharp/exception.hpp"
//
// The char type keyword is an alias for the .NET System.Char structure type that represents a Unicode UTF-16 character.
// https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/char
//
namespace csharp {
struct UnicodeUtility {
// The Unicode replacement character U+FFFD.
inline static uint32_t ReplacementChar = 0xFFFD;
// Returns the Unicode plane (0 through 16, inclusive) which contains this code point.
static constexpr int32_t GetPlane(uint32_t codePoint) {
return static_cast<int32_t>(codePoint >> 16);
}
// Returns a Unicode scalar value from two code points representing a UTF-16 surrogate pair.
static constexpr uint32_t GetScalarFromUtf16SurrogatePair(uint32_t highSurrogateCodePoint, uint32_t lowSurrogateCodePoint) {
return (highSurrogateCodePoint << 10) + lowSurrogateCodePoint - ((0xD800U << 10) + 0xDC00U - (1 << 16));
}
// Given a Unicode scalar value, gets the number of UTF-16 code units required to represent this value.
static constexpr int32_t GetUtf16SequenceLength(uint32_t value) {
value -= 0x10000;
value += (2 << 24);
value >>= 24;
return static_cast<int32_t>(value);
}
// Decomposes an astral Unicode scalar into UTF-16 high and low surrogate code units.
static constexpr void GetUtf16SurrogatesFromSupplementaryPlaneScalar(uint32_t value, char16_t& highSurrogateCodePoint, char16_t& lowSurrogateCodePoint) {
highSurrogateCodePoint = static_cast<char16_t>((value + ((0xD800u - 0x40u) << 10)) >> 10);
lowSurrogateCodePoint = static_cast<char16_t>((value & 0x3FFu) + 0xDC00u);
}
// Given a Unicode scalar value, gets the number of UTF-8 code units required to represent this value.
static constexpr int32_t GetUtf8SequenceLength(uint32_t value) {
int32_t a = (static_cast<int32_t>(value) - 0x0800) >> 31;
value ^= 0xF800u;
value -= 0xF880u;
value += (4 << 24);
value >>= 24;
return static_cast<int32_t>(value) + (a * 2);
}
// Returns true if is an ASCII
static constexpr bool IsAsciiCodePoint(uint32_t value) {
return value <= 0x7Fu;
}
//Returns true if is a UTF-16 high surrogate code point, i.e., is in [ U+D800..U+DBFF ], inclusive.
static constexpr bool IsHighSurrogateCodePoint(uint32_t value) {
return IsInRangeInclusive(value, 0xD800U, 0xDBFFU);
}
//Returns true if is between
static constexpr bool IsInRangeInclusive(uint32_t value, uint32_t lowerBound, uint32_t upperBound) {
return (value - lowerBound) <= (upperBound - lowerBound);
}
//Returns true if value is a UTF-16 low surrogate code point, i.e., is in [ U+DC00..U+DFFF ], inclusive.
static constexpr bool IsLowSurrogateCodePoint(uint32_t value) {
return IsInRangeInclusive(value, 0xDC00U, 0xDFFFU);
}
//Returns true if value is a UTF-16 low surrogate code point, i.e., is in [ U+D800..U+DFFF ], inclusive.
static constexpr bool IsSurrogateCodePoint(uint32_t value) {
return IsInRangeInclusive(value, 0xD800U, 0xDFFFU);
}
//Returns true if value is a valid Unicode code point, i.e., is in [ U+0000..U+10FFFF ], inclusive.
static constexpr bool IsValidCodePoint(uint32_t codePoint) {
return codePoint <= 0x10FFFFU;
}
//Returns true if value is a valid Unicode scalar value, i.e., is in [ U+0000..U+D7FF ], inclusive; or [ U+E000..U+10FFFF ], inclusive.
static constexpr bool IsValidUnicodeScalar(uint32_t value) {
return ((value - 0x110000u) ^ 0xD800u) >= 0xFFEF0800u;
}
};
}
#endif