diff options
Diffstat (limited to 'src/win/String.cpp')
| -rw-r--r-- | src/win/String.cpp | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/src/win/String.cpp b/src/win/String.cpp new file mode 100644 index 00000000..65a280f2 --- /dev/null +++ b/src/win/String.cpp @@ -0,0 +1,188 @@ +#include "cru/win/String.hpp" + +#include "cru/win/Exception.hpp" + +#include <type_traits> + +namespace cru::platform::win { +std::string ToUtf8String(const std::wstring_view& string) { + if (string.empty()) return std::string{}; + + const auto length = ::WideCharToMultiByte( + CP_UTF8, WC_ERR_INVALID_CHARS, string.data(), + static_cast<int>(string.size()), nullptr, 0, nullptr, nullptr); + if (length == 0) { + throw Win32Error(::GetLastError(), + "Failed to convert wide string to UTF-8."); + } + + std::string result; + result.resize(length); + if (::WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, string.data(), + static_cast<int>(string.size()), result.data(), + static_cast<int>(result.size()), nullptr, + nullptr) == 0) + throw Win32Error(::GetLastError(), + "Failed to convert wide string to UTF-8."); + return result; +} + +std::wstring ToUtf16String(const std::string_view& string) { + if (string.empty()) return std::wstring{}; + + const auto length = + ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, string.data(), + static_cast<int>(string.size()), nullptr, 0); + if (length == 0) { + throw Win32Error(::GetLastError(), + "Failed to convert wide string to UTF-16."); + } + + std::wstring result; + result.resize(length); + if (::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, string.data(), + static_cast<int>(string.size()), result.data(), + static_cast<int>(result.size())) == 0) + throw win::Win32Error(::GetLastError(), + "Failed to convert wide string to UTF-16."); + return result; +} + +template <typename UInt, int number_of_bit> +inline std::enable_if_t<std::is_unsigned_v<UInt>, CodePoint> ExtractBits( + UInt n) { + return static_cast<CodePoint>(n & ((1u << number_of_bit) - 1)); +} + +CodePoint Utf8Iterator::Next() { + if (position_ == static_cast<int>(string_.length())) return k_code_point_end; + + const auto cu0 = static_cast<std::uint8_t>(string_[position_++]); + + auto read_next_folowing_code = [this]() -> CodePoint { + if (this->position_ == static_cast<int>(string_.length())) + throw TextEncodeException( + "Unexpected end when read continuing byte of multi-byte code point."); + +#ifdef CRU_DEBUG + const auto u = static_cast<std::uint8_t>(string_[position_]); + if (!(u & (1u << 7)) || (u & (1u << 6))) { + throw TextEncodeException( + "Unexpected bad-format (not 0b10xxxxxx) continuing byte of " + "multi-byte code point."); + } +#endif + + return ExtractBits<std::uint8_t, 6>(string_[position_++]); + }; + + if ((1u << 7) & cu0) { + if ((1u << 6) & cu0) { // 2~4-length code point + if ((1u << 5) & cu0) { // 3~4-length code point + if ((1u << 4) & cu0) { // 4-length code point +#ifdef CRU_DEBUG + if (cu0 & (1u << 3)) { + throw TextEncodeException( + "Unexpected bad-format begin byte (not 0b10xxxxxx) of 4-byte " + "code point."); + } +#endif + + const CodePoint s0 = ExtractBits<std::uint8_t, 3>(cu0) << (6 * 3); + const CodePoint s1 = read_next_folowing_code() << (6 * 2); + const CodePoint s2 = read_next_folowing_code() << 6; + const CodePoint s3 = read_next_folowing_code(); + return s0 + s1 + s2 + s3; + } else { // 3-length code point + const CodePoint s0 = ExtractBits<std::uint8_t, 4>(cu0) << (6 * 2); + const CodePoint s1 = read_next_folowing_code() << 6; + const CodePoint s2 = read_next_folowing_code(); + return s0 + s1 + s2; + } + } else { // 2-length code point + const CodePoint s0 = ExtractBits<std::uint8_t, 5>(cu0) << 6; + const CodePoint s1 = read_next_folowing_code(); + return s0 + s1; + } + } else { + throw TextEncodeException( + "Unexpected bad-format (0b10xxxxxx) begin byte of a code point."); + } + } else { + return static_cast<CodePoint>(cu0); + } +} + +CodePoint Utf16Iterator::Next() { + if (position_ == static_cast<int>(string_.length())) return k_code_point_end; + + const auto cu0 = static_cast<std::uint16_t>(string_[position_++]); + + if (cu0 < 0xd800u || cu0 >= 0xe000u) { // 1-length code point + return static_cast<CodePoint>(cu0); + } else if (cu0 <= 0xdbffu) { // 2-length code point + if (position_ == static_cast<int>(string_.length())) { + throw TextEncodeException( + "Unexpected end when reading second code unit of surrogate pair."); + } + const auto cu1 = static_cast<std::uint16_t>(string_[position_++]); + +#ifdef CRU_DEBUG + if (cu1 < 0xDC00u || cu1 > 0xdfffu) { + throw TextEncodeException( + "Unexpected bad-format second code unit of surrogate pair."); + } +#endif + + const auto s0 = ExtractBits<std::uint16_t, 10>(cu0) << 10; + const auto s1 = ExtractBits<std::uint16_t, 10>(cu1); + + return s0 + s1 + 0x10000; + + } else { + throw TextEncodeException( + "Unexpected bad-format first code unit of surrogate pair."); + } +} + +int IndexUtf8ToUtf16(const std::string_view& utf8_string, int utf8_index, + const std::wstring_view& utf16_string) { + if (utf8_index >= static_cast<int>(utf8_string.length())) + return static_cast<int>(utf16_string.length()); + + int cp_index = 0; + Utf8Iterator iter{utf8_string}; + while (iter.CurrentPosition() <= utf8_index) { + iter.Next(); + cp_index++; + } + + Utf16Iterator result_iter{utf16_string}; + for (int i = 0; i < cp_index - 1; i++) { + if (result_iter.Next() == k_code_point_end) break; + } + + return result_iter.CurrentPosition(); +} + +int IndexUtf16ToUtf8(const std::wstring_view& utf16_string, int utf16_index, + const std::string_view& utf8_string) { + if (utf16_index >= static_cast<int>(utf16_string.length())) + return static_cast<int>(utf8_string.length()); + + int cp_index = 0; + Utf16Iterator iter{utf16_string}; + while (iter.CurrentPosition() <= utf16_index) { + iter.Next(); + cp_index++; + } + + Utf8Iterator result_iter{utf8_string}; + for (int i = 0; i < cp_index - 1; i++) { + if (result_iter.Next() == k_code_point_end) break; + } + + return result_iter.CurrentPosition(); +} + +} // namespace cru::platform::win |