aboutsummaryrefslogtreecommitdiff
path: root/src/common/StringUtil.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/common/StringUtil.cpp')
-rw-r--r--src/common/StringUtil.cpp179
1 files changed, 136 insertions, 43 deletions
diff --git a/src/common/StringUtil.cpp b/src/common/StringUtil.cpp
index 31a5effd..0b6332ce 100644
--- a/src/common/StringUtil.cpp
+++ b/src/common/StringUtil.cpp
@@ -1,5 +1,7 @@
#include "cru/common/StringUtil.hpp"
+#include <codecvt>
+
namespace cru {
template <typename UInt, int number_of_bit>
inline std::enable_if_t<std::is_unsigned_v<UInt>, CodePoint> ExtractBits(
@@ -7,63 +9,154 @@ inline std::enable_if_t<std::is_unsigned_v<UInt>, CodePoint> ExtractBits(
return static_cast<CodePoint>(n & ((1u << number_of_bit) - 1));
}
-CodePoint Utf8Iterator::Next() {
- if (position_ == static_cast<Index>(string_.length()))
- return k_code_point_end;
+CodePoint Utf16Iterator::Previous() {
+ if (position_ <= 0) return k_invalid_code_point;
- const auto cu0 = static_cast<std::uint8_t>(string_[position_++]);
+ const auto cu0 = static_cast<std::uint16_t>(string_[--position_]);
- auto read_next_folowing_code = [this]() -> CodePoint {
- if (this->position_ == static_cast<Index>(string_.length()))
+ if (cu0 < 0xd800u || cu0 >= 0xe000u) { // 1-length code point
+ return static_cast<CodePoint>(cu0);
+ } else if (cu0 < 0xdc00u || cu0 > 0xdfffu) { // 2-length code point
+ if (position_ <= 0) {
throw TextEncodeException(
- "Unexpected end when read continuing byte of multi-byte code point.");
+ "Unexpected end when reading first code unit of surrogate pair "
+ "during backward.");
+ }
+ const auto cu1 = static_cast<std::uint16_t>(string_[--position_]);
#ifdef CRU_DEBUG
- const auto u = static_cast<std::uint8_t>(string_[position_]);
- if (!(u & (1u << 7)) || (u & (1u << 6))) {
+ if (cu1 <= 0xdbffu) {
throw TextEncodeException(
- "Unexpected bad-format (not 0b10xxxxxx) continuing byte of "
- "multi-byte code point.");
+ "Unexpected bad-range first code unit of surrogate pair during "
+ "backward.");
}
#endif
- return ExtractBits<std::uint8_t, 6>(string_[position_++]);
- };
+ const auto s0 = ExtractBits<std::uint16_t, 10>(cu1) << 10;
+ const auto s1 = ExtractBits<std::uint16_t, 10>(cu0);
- 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
+ return s0 + s1 + 0x10000;
+
+ } else {
+ throw TextEncodeException(
+ "Unexpected bad-range second code unit of surrogate pair during "
+ "backward.");
+ }
+}
- 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 {
+CodePoint Utf16Iterator::Next() {
+ if (position_ >= static_cast<Index>(string_.length()))
+ return k_invalid_code_point;
+
+ 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<Index>(string_.length())) {
throw TextEncodeException(
- "Unexpected bad-format (0b10xxxxxx) begin byte of a code point.");
+ "Unexpected end when reading second code unit of surrogate pair "
+ "during forward.");
}
+ 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 during "
+ "forward.");
+ }
+#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 {
- return static_cast<CodePoint>(cu0);
+ throw TextEncodeException(
+ "Unexpected bad-format first code unit of surrogate pair during "
+ "forward.");
}
}
+
+Index PreviousIndex(std::u16string_view string, Index current) {
+ Utf16Iterator iterator{string, current};
+ iterator.Previous();
+ return iterator.CurrentPosition();
+}
+
+Index NextIndex(std::u16string_view string, Index current) {
+ Utf16Iterator iterator{string, current};
+ iterator.Next();
+ return iterator.CurrentPosition();
+}
+
+std::string ToUtf8(const std::u16string& s) {
+ // TODO: Implement this by myself.
+ return std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t>{}
+ .to_bytes(s);
+}
+
+// CodePoint Utf8Iterator::Next() {
+// if (position_ == static_cast<Index>(string_.length()))
+// return k_invalid_code_point;
+
+// const auto cu0 = static_cast<std::uint8_t>(string_[position_++]);
+
+// auto read_next_folowing_code = [this]() -> CodePoint {
+// if (this->position_ == static_cast<Index>(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);
+// }
+// }
+
} // namespace cru
generated by cgit v1.2.3 (git 2.46.0) at 2025-09-28 17:38:33 +0000