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-rw-r--r--src/openvic-dataloader/detail/Detect.hpp627
1 files changed, 627 insertions, 0 deletions
diff --git a/src/openvic-dataloader/detail/Detect.hpp b/src/openvic-dataloader/detail/Detect.hpp
new file mode 100644
index 0000000..ad36d04
--- /dev/null
+++ b/src/openvic-dataloader/detail/Detect.hpp
@@ -0,0 +1,627 @@
+/// Based heavily on https://github.com/hsivonen/chardetng/tree/143dadde20e283a46ef33ba960b517a3283a3d22
+
+#pragma once
+
+#include <array>
+#include <cassert>
+#include <cstdint>
+#include <optional>
+#include <span>
+#include <type_traits>
+#include <variant>
+#include <vector>
+
+#include <openvic-dataloader/detail/Encoding.hpp>
+
+#include <lexy/action/match.hpp>
+#include <lexy/callback/constant.hpp>
+#include <lexy/dsl.hpp>
+#include <lexy/dsl/ascii.hpp>
+#include <lexy/dsl/newline.hpp>
+#include <lexy/encoding.hpp>
+#include <lexy/input/buffer.hpp>
+
+#include "detail/dsl.hpp"
+
+namespace ovdl::encoding_detect {
+ using cbyte = char;
+ using ubyte = unsigned char;
+
+ using Encoding = detail::Encoding;
+
+ struct DetectAscii {
+ // & 0b10000000 == 0b00000000
+ static constexpr auto rule = lexy::dsl::while_(lexy::dsl::ascii::character) + lexy::dsl::eol;
+ static constexpr auto value = lexy::constant(true);
+ };
+
+ template<bool IncludeAscii>
+ struct DetectUtf8 {
+ struct not_utf8 {
+ static constexpr auto name = "not utf8";
+ };
+
+ static constexpr auto rule = [] {
+ constexpr auto is_not_ascii_flag = lexy::dsl::context_flag<DetectUtf8>;
+
+ // & 0b10000000 == 0b00000000
+ constexpr auto ascii_values = lexy::dsl::ascii::character;
+ // & 0b11100000 == 0b11000000
+ constexpr auto two_byte = dsl::lit_b_range<0b11000000, 0b11011111>;
+ // & 0b11110000 == 0b11100000
+ constexpr auto three_byte = dsl::lit_b_range<0b11100000, 0b11101111>;
+ // & 0b11111000 == 0b11110000
+ constexpr auto four_byte = dsl::lit_b_range<0b11110000, 0b11110111>;
+ // & 0b11000000 == 0b10000000
+ constexpr auto check_bytes = dsl::lit_b_range<0b10000000, 0b10111111>;
+
+ constexpr auto utf8_check =
+ ((four_byte >> lexy::dsl::times<3>(check_bytes)) |
+ (three_byte >> lexy::dsl::times<2>(check_bytes)) |
+ (two_byte >> lexy::dsl::times<1>(check_bytes))) >>
+ is_not_ascii_flag.set();
+
+ return is_not_ascii_flag.template create<IncludeAscii>() +
+ lexy::dsl::while_(utf8_check | ascii_values) +
+ lexy::dsl::must(is_not_ascii_flag.is_set()).template error<not_utf8> + lexy::dsl::eof;
+ }();
+
+ static constexpr auto value = lexy::constant(true);
+ };
+
+ extern template struct DetectUtf8<true>;
+ extern template struct DetectUtf8<false>;
+
+ template<typename Input>
+ constexpr bool is_ascii(const Input& input) {
+ return lexy::match<DetectAscii>(input);
+ }
+
+ template<typename Input>
+ constexpr bool is_utf8_no_ascii(const Input& input) {
+ return lexy::match<DetectUtf8<false>>(input);
+ }
+
+ template<typename Input>
+ constexpr bool is_utf8(const Input& input) {
+ return lexy::match<DetectUtf8<true>>(input);
+ }
+
+ struct DetectorData {
+ static constexpr std::array latin_ascii = std::to_array<ubyte>({
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //
+ 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 0, 0, 0, 0, 0, 0, //
+ 0, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, //
+ 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 0, 0, 0, 0, 0, //
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, //
+ 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 0, 0, 0, 0, 0, //
+ });
+
+ static constexpr std::array non_latin_ascii = std::to_array<ubyte>({
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //
+ 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 0, 0, 0, 0, 0, 0, //
+ 0, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, //
+ 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 0, 0, 0, 0, 0, //
+ 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, //
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, //
+ });
+
+ static constexpr std::array windows_1251 = std::to_array<ubyte>({
+ 131, 130, 0, 2, 0, 0, 0, 0, 0, 0, 132, 0, 133, 130, 134, 135, //
+ 3, 0, 0, 0, 0, 0, 0, 0, 255, 0, 4, 0, 5, 2, 6, 7, //
+ 0, 136, 8, 140, 47, 130, 46, 47, 138, 49, 139, 49, 50, 46, 48, 141, //
+ 49, 50, 137, 9, 2, 49, 48, 46, 10, 47, 11, 48, 12, 130, 2, 13, //
+ 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, //
+ 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, //
+ 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, //
+ 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, //
+ });
+
+ static constexpr std::array windows_1252 = std::to_array<ubyte>({
+ 0, 255, 0, 60, 0, 0, 0, 0, 0, 0, 156, 0, 157, 255, 185, 255, //
+ 255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 28, 0, 29, 255, 57, 186, //
+ 0, 62, 60, 60, 60, 60, 59, 60, 60, 62, 60, 59, 63, 59, 61, 60, //
+ 62, 63, 61, 61, 60, 62, 61, 59, 60, 61, 60, 59, 62, 62, 62, 62, //
+ 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, //
+ 188, 174, 175, 176, 177, 178, 179, 63, 180, 181, 182, 183, 184, 188, 188, 27, //
+ 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, //
+ 60, 46, 47, 48, 49, 50, 51, 63, 52, 53, 54, 55, 56, 60, 60, 58, //
+ });
+
+ // clang-format off
+ static constexpr std::array cyrillic = std::to_array<ubyte>({
+ 0, 0, 0, 0, 1, 0, 16, 38, 0, 2, 5, 10,121, 4, 20, 25, 26, 53, 9, 5, 61, 23, 20, 26, 15, 95, 60, 2, 26, 15, 25, 29, 0, 14, 6, 6, 25, 1, 0, 27, 25, 8, 5, 39, // ,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // a,
+ 0, 0, 0,255, 0, 0,255, 0,255, 0,255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,255,255, 0, 0,255, 0, 0, // ѓ,
+ 0, 0,255, 0, 0, 0, 0, 0,255,255,255,255, 0,255, 2, 0, 0, 0, 0, 0, 0, 0, 0,255, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,255,255,255,255,255,255,255, // ђ,
+ 0, 0, 0, 0, 0, 0, 0, 0,255,255,255,255, 0,255, 0, 0, 0, 0, 0, 4, 0, 0, 0,255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,255,255,255,255,255,255,255, // љ,
+ 0, 0, 0, 0, 0, 0, 0, 0,255,255,255, 0, 0,255, 5, 0, 0, 0, 0, 2, 0, 0, 0,255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,255,255,255,255,255,255,255, // њ,
+ 0, 0,255, 0, 0, 0, 0, 0,255, 0,255,255, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 1,255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,255,255,255,255,255,255,255, // ћ,
+ 0, 0, 0, 0, 0, 0, 0, 0,255,255,255,255, 0,255, 0, 0, 0, 0, 0, 0, 0, 0, 0,255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,255,255,255,255,255,255,255, // џ,
+ 7, 0, 0,255,255,255,255,255, 0, 1, 0,255,255,255, 15, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,255,255, 1, 0, 0, 0, 1, // ў,
+ 12, 0, 0,255,255, 0,255,255, 0, 2, 0, 0, 0, 0, 2, 3, 15, 5, 5, 0, 0, 4, 0, 0, 21, 15, 10, 17, 0, 6, 14, 4, 6, 0, 3, 1, 8, 1, 0, 0, 0, 2, 0, 0, 0, 0, // і,
+ 0, 0,255,255,255,255,255,255, 0, 0, 0,255,255, 0, 4, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ё,
+ 6, 0, 0,255,255,255,255,255, 0, 0,255, 5,255, 0, 1, 7, 0, 3, 2, 0, 0, 0, 0, 0, 0, 2, 2, 2, 0, 0, 2, 2, 5, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // є,
+ 12, 0, 0, 0, 0, 0, 0, 0,255, 0,255, 0, 0, 0, 5, 1, 0, 0, 0, 2, 0, 0, 20,255, 0, 0, 0, 0, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,255,255, 0,255,255,255,255, // ј,
+ 9, 0, 0,255,255,255,255,255,255, 5,255, 0, 0, 13, 3, 3, 0, 4, 1, 0, 1, 2, 0, 0, 0, 1, 0, 0, 4, 0, 0, 1, 3, 0, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ї,
+ 32, 0, 0, 2, 2, 2, 0, 0, 0, 1, 0, 0, 28, 0, 23, 22, 26, 22, 19, 0, 3, 12, 5, 0, 44, 38, 18, 58, 1, 21, 44, 17, 54, 1, 2, 28, 5, 8, 3, 1, 9, 0, 12, 0, 0, 0, // а,
+ 40, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 7, 0, 0, 0, 1, 7, 0, 1, 1, 0, 0, 7, 4, 1, 9, 0, 1, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, // б,
+ 31, 0, 0, 0, 0, 0, 0, 0, 0, 11, 0, 3, 0, 0, 19, 0, 0, 1, 1, 6, 0, 2, 6, 0, 1, 0, 1, 0, 32, 0, 2, 2, 23, 9, 0, 0, 0, 1, 0, 0, 1, 1, 0, 3, 0, 2, // в,
+ 23, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 7, 0, 1, 20, 0, 0, 1, 0, 9, 0, 0, 9, 7, 0, 5, 2, 18, 11, 0, 8, 3, 2, 3, 0, 0, 0, 0, 0, 0, 0, 3, 0, 13, 0, 3, // г,
+ 26, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 2, 0, 2, 19, 0, 1, 5, 0, 13, 2, 2, 3, 2, 0, 6, 1, 12, 30, 0, 4, 0, 0, 7, 0, 0, 0, 0, 0, 0, 1, 0, 0, 5, 0, 1, // д,
+ 12, 0, 0, 1, 4, 5, 0, 0, 0, 0, 0, 0, 24, 1, 5, 7, 11, 3, 12, 1, 6, 6, 11, 0, 3, 15, 14, 14, 4, 8, 25, 14, 29, 0, 1, 1, 4, 8, 8, 2, 0, 3, 1, 0, 0, 0, // е,
+ 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 1, 2, 2, 0, 0, 0, 0, 0, 3, 2, 1, 2, 0, 2, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, // ж,
+ 19, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 1, 6, 0, 0, 0, 11, 8, 0, 0, 8, 0, 0, 0, 0, 0, 4, 0, 1, 0, 0, 3, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, // з,
+ 24, 0, 0, 0, 0, 1, 5, 0, 0, 0, 0, 0, 1, 0, 1, 10, 16, 21, 22, 0, 6, 5, 6, 1, 15, 15, 8, 38, 2, 4, 27, 9, 15, 0, 3, 8, 12, 7, 6, 1, 0, 0, 0, 0, 0, 0, // и,
+ 6, 0, 0, 0,255,255,255,255, 0, 7, 0, 0,255, 4, 21, 0, 0, 0, 0, 5, 0, 0, 39, 0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 5, 0, 3, 0, 0, // й,
+ 54, 0, 0, 0, 0, 0, 0, 0, 1, 8, 0, 0, 0, 0, 10, 0, 1, 0, 1, 11, 0, 0, 12, 0, 1, 2, 0, 4, 8, 0, 2, 23, 2, 4, 0, 2, 3, 3, 8, 0, 0, 3, 16, 1, 4, 3, // к,
+ 12, 0, 0, 0, 0, 0, 0, 0, 2, 6, 0, 6, 0, 4, 29, 12, 4, 5, 2, 18, 0, 0, 17, 4, 5, 11, 0, 0, 21, 2, 3, 4, 1, 15, 1, 0, 0, 0, 0, 0, 4, 3, 2, 12, 0, 2, // л,
+ 23, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 4, 0, 0, 17, 1, 0, 0, 0, 7, 0, 1, 13, 2, 0, 0, 0, 0, 13, 0, 2, 4, 0, 2, 0, 0, 0, 0, 0, 0, 1, 4, 2, 4, 1, 1, // м,
+ 42, 0, 0, 0, 0, 0, 0, 0, 4, 12, 6, 7, 1, 7, 76, 0, 22, 1, 4, 27, 1, 3, 34, 30, 0, 7, 1, 13, 24, 1, 3, 5, 3, 4, 0, 1, 0, 4, 1, 0, 2, 18, 7, 16, 0, 4, // н,
+ 37, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 1, 0, 1, 10, 27, 22, 15, 1, 2, 3, 7, 5, 32, 11, 7, 38, 8, 21, 24, 11, 23, 0, 2, 10, 2, 2, 3, 2, 0, 0, 1, 0, 0, 0, // о,
+ 47, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 1, 0, 0, 2, 0, 1, 2, 4, 0, 0, 2, 0, 6, 0, 0, 5, 0, 2, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, // п,
+ 19, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 8, 0, 5, 47, 4, 6, 6, 5, 23, 0, 0, 5, 2, 6, 0, 0, 0, 23, 22, 0, 1, 14, 9, 1, 0, 1, 0, 0, 0, 7, 2, 8, 16, 0, 3, // р,
+ 53, 0, 0, 0, 0, 0, 0, 0, 4, 9, 2, 0, 1, 2, 21, 1, 4, 1, 2, 11, 0, 0, 12, 2, 4, 7, 1, 13, 15, 1, 4, 6, 3, 6, 0, 0, 0, 0, 0, 0, 1, 2, 3, 5, 0, 1, // с,
+ 28, 0, 0, 0, 0, 0, 0, 0, 1, 6, 0, 1, 0, 1, 32, 0, 1, 3, 0, 12, 0, 1, 22, 1, 4, 7, 1, 6, 23, 0, 14, 41, 14, 3, 0, 1, 1, 1, 21, 0, 2, 2, 6, 2, 1, 4, // т,
+ 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 2, 4, 2, 4, 6, 3, 0, 2, 0, 0, 6, 5, 6, 3, 0, 3, 7, 4, 7, 18, 1, 6, 0, 2, 0, 0, 0, 0, 0, 0, 1, 0, // у,
+ 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ф,
+ 41, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 1, 0, 2, 30, 0, 2, 0, 0, 11, 0, 0, 5, 1, 14, 3, 0, 3, 6, 0, 7, 0, 0, 1, 0, 1, 0, 2, 0, 0, 0, 4, 3, 5, 0, 0, // х,
+ 8, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 7, 0, 0, 0, 0, 4, 0, 0, 7, 1, 0, 1, 0, 2, 1, 0, 0, 9, 0, 0, 0, 0, 2, 0, 0, 0, 0, 1, 0, 0, 1, 1, // ц,
+ 6, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 5, 0, 1, 5, 0, 2, 0, 0, 6, 0, 0, 1, 0, 0, 3, 0, 2, 0, 0, 2, 0, 1, 0, 0, 3, 0, 0, 2, 0, 0, 0, 0, // ч,
+ 12, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 17, 0, 0, 1, 0, 2, 0, 0, 26, 0, 0, 0, 0, 0, 22, 2, 6, 0, 0, 5, 0, 0, 0, 0, 2, 0, 0, 1, 0, 0, 0, 0, // ш,
+ 2, 0,255, 0,255,255,255,255,255, 0, 0, 0,255, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, // щ,
+ 0, 0,255,255,255,255, 0,255, 0, 0, 0,255,255,255, 0, 3, 4, 0, 2, 0, 0, 0, 0, 0, 11, 0, 1, 0, 0, 2, 2, 5, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ъ,
+ 1, 0, 0,255,255,255,255,255, 0, 0, 0, 0, 0,255, 0, 3, 11, 0, 4, 0, 2, 1, 0, 0, 0, 3, 1, 16, 0, 0, 22, 2, 10, 0, 0, 0, 8, 6, 3, 0, 0, 0, 0, 0, 0, 0, // ы,
+ 0, 0, 0,255,255, 0, 0, 0,255, 0, 0, 0, 0, 0, 5, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 15, 0, 7, 3, 0, 1, 13, 7, 7, 0, 35, 6, 0, 0, 0, 0, 0, 0, 0, 6, 0, // ь,
+ 10, 0, 0,255,255,255,255,255, 0, 0, 0, 0,255, 0, 0, 1, 1, 10, 11, 0, 2, 2, 0, 0, 0, 9, 3, 9, 0, 0, 7, 6, 9, 0, 0, 8, 3, 2, 1, 0, 0, 0, 0, 17, 0, 0, // э,
+ 14, 0, 0, 0,255,255,255,255, 0, 0, 0, 0,255, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 2, 0, 0, 2, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ю,
+ 5, 0, 0,255,255,255,255,255, 0, 9, 0, 0,255, 0, 11, 0, 3, 0, 0, 0, 0, 2, 24, 0, 0, 5, 2, 14, 1, 0, 2, 3, 1, 0, 0, 1, 3, 0, 0, 0, 0, 16, 1, 0, 0, 0, // я,
+ // , a, ѓ, ђ, љ, њ, ћ, џ, ў, і, ё, є, ј, ї, а, б, в, г, д, е, ж, з, и, й, к, л, м, н, о, п, р, с, т, у, ф, х, ц, ч, ш, щ, ъ, ы, ь, э, ю, я,
+ });
+ // clang-format on
+
+ // clang-format off
+ static constexpr std::array western = std::to_array<ubyte>({
+ 18, 3, 0,254, 74, 0, 5,254,254, 2, 25,254,149, 4,254, 66,148,254, 0,254,122,238, 8, 1, 20, 13,254, 35, 20, 3, 1, 0, // ,
+ 0, 3, 0, 0, 0, 0, 0, 5, 2, 0, 86, 9, 76, 0, 0, 0,241, 0, 0, 49, 0, 0, 0, 0, 11, 2, 0, 34, 0, 1, 2, 0, // a,
+ 19, 0, 0, 5, 5, 0, 0, 8, 13, 5, 0, 34, 22, 0, 0, 0, 4, 0, 0, 0, 6, 1, 3, 3, 42, 37, 8, 8, 0, 67, 0, 0, // b,
+ 0, 0, 0, 9, 6, 1, 0, 22, 10, 1, 0, 19, 54, 1, 0, 1, 18, 3, 1, 2, 40, 7, 0, 0, 6, 0, 3, 5, 1, 34, 0, 0, // c,
+ 0, 0, 0, 5, 5, 0, 0, 12, 45, 16, 1, 6, 42, 0, 13, 3, 10, 0, 2, 0, 66, 11, 5, 8, 33,104, 3, 4, 0, 19, 0, 0, // d,
+ 63, 5, 0, 0, 0, 0, 2, 33, 15, 1, 3, 0, 87, 0, 0, 0, 0, 0, 1, 21, 0, 0, 0, 49, 1, 11, 0, 3, 0, 9, 1, 0, // e,
+ 0, 0, 0, 8, 8, 0, 0, 10, 2, 7, 0,162, 23, 0, 13, 0, 4, 0, 0, 0, 1, 3, 0, 0, 15, 4, 0, 0, 0, 4, 0, 0, // f,
+ 1, 0, 0, 14, 16, 24, 0, 29, 11, 41, 0, 13, 86, 0, 14, 9, 3, 0, 0, 0, 20, 8, 7, 7, 13, 37, 14, 0, 0, 12, 0, 0, // g,
+ 1, 0, 0, 0, 0, 0, 0, 47, 2, 0, 0, 0, 1, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 29, 20, 0, 0, 0, 0, 45, 0, 0, // h,
+ 5, 4, 0,166,120, 0, 0,144, 0, 2, 3, 88,254, 0, 0, 0, 0, 0, 0, 3, 28,107, 0,112, 8, 2, 44, 32, 0, 3, 3, 0, // i,
+ 0, 0, 0, 0, 0, 0, 0, 39, 9, 0, 0, 2, 1, 0, 2, 0, 0, 0, 0, 4, 0, 0, 0, 16, 18, 44, 0, 0, 0, 0, 0,255, // j,
+ 0, 2, 0, 0, 1, 0, 0, 48, 31, 32, 1, 60, 1, 0, 4, 0, 1, 0, 0, 0, 1, 3, 0, 2, 20, 47, 0, 0, 0, 20, 0, 0, // k,
+ 4, 0, 0, 12, 16, 0, 0, 54, 40, 48, 0, 64, 36, 0, 39, 6, 12, 3, 0, 0, 27, 9, 3, 24, 42, 33, 2, 9, 7, 77, 0, 0, // l,
+ 0, 0, 0, 14, 5, 4, 0, 60, 11, 4, 3, 48, 30, 7, 28, 1, 10, 1, 0, 0, 24, 41, 3, 3, 19, 24, 1, 8, 2, 36, 0, 0, // m,
+ 1, 1, 0, 24, 91, 16, 0,132, 62, 73, 1, 56, 71, 33, 78, 7, 35, 2, 3, 0, 94,254, 10, 21, 33, 38, 24, 21, 1, 61, 0, 0, // n,
+ 0, 1, 0, 0, 0, 0,254, 6, 0, 1, 27, 0, 13, 0, 0, 84,127, 0, 0, 62, 0, 1, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, // o,
+ 0, 0, 0, 5, 2, 0, 0, 9, 15, 0, 0, 4, 34, 0, 6, 0, 6, 0, 0, 0, 20, 12, 9, 28, 10, 22, 0, 3, 0, 7, 0, 0, // p,
+ 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 33, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,255,255, // q,
+ 0, 0, 0, 83, 62, 1, 0,198,139,125, 0,229, 94, 54,190, 38, 18, 1, 0, 0,176, 24, 16, 29,193,181, 13, 13, 2,131, 0, 0, // r,
+ 1, 0, 0, 41, 34, 0, 0, 41, 24, 42, 0, 68,113, 15,159, 6, 43, 19, 4, 58, 14, 18, 1, 4, 48, 42, 4, 12, 9, 20, 0, 0, // s,
+ 7, 1, 0, 14, 20, 8, 0, 56, 37, 31, 0,104, 67, 14,113, 3, 50, 9, 5, 0, 89, 7, 19, 22, 13, 14, 40, 12, 15, 18, 0, 0, // t,
+ 0, 1, 5, 1, 2, 0, 0, 30, 0, 0, 1, 15, 2, 0, 1, 0, 1, 0, 0, 2, 4, 0, 0, 36, 0, 0, 0, 0, 0, 0, 0, 0, // u,
+ 0, 2, 0, 1, 6, 0, 0, 29, 33, 13, 0, 19, 46, 0, 15, 0, 7, 0, 1, 31, 2, 2, 3, 1, 32, 27, 0, 0, 1, 1, 0, 0, // v,
+ 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 3, 0, 0, 4, 0, 0, 0, 0, 0, 0, 2, 0, 0, 1, 0, 0, 0, 0, 0, 0,255, // w,
+ 0, 0, 0, 1, 16, 0, 0, 23, 0, 0, 0, 3, 14, 0, 0, 0, 2, 3, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0,255, 0, // x,
+ 0, 0, 0, 0, 0, 0, 0, 58, 8, 0, 0, 1, 1, 62, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 6, 82, 0, 0, 0, 0, 0,255, // y,
+ 0, 0, 0, 0, 2, 0, 0, 0, 14, 0, 0, 7, 3, 0, 6, 0, 3, 5, 0, 0, 0, 0, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, // z,
+ 0, 29, 0, 0, 0, 15, 0, 0, 0, 11, 0, 0, 0, 0, 0, 20, 0, 0, 0, 0, 0, 37, 0, 0, 0, 0, 0, 0,255,255, 0, 0,255,255, 4, 0, 0,255,255, 0,255, 0,255, 0, 0,255,255,255, 0, 0, 0, 8, 0,255, 0, 0, 2, 0, 0, // ß,
+ 6, 2, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 10, 1, 0, 0, 0, 0, 0, 0, 0,255, 0, 1, 0, 0, 0, 0, 0,255, 0, 0, 0, 0, 0, 0, 0,255,255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // š,
+ 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,255, 0, 0, 0, 0, 0, 0, 0, 0, 0,255, 0, 0,255,255,255, 0, 0, 0,255,255,255, 0,255,255,255,255, 0, 0,255,255,255,255,255,255, 0,255,255,255, 0,255,255, // œ,
+ 107, 0, 22, 16, 18, 14, 6, 24, 46, 15, 2, 0, 42, 18, 17, 0, 36, 0, 34, 4,254, 1, 2, 0, 0, 1, 0, 0, 0,255, 0, 0, 0, 0, 0,255,255, 0, 0, 0, 0, 0, 0, 0,255, 0, 0, 0,255,255,255,255,255, 0, 0,255, 0, 0, 0, // à,
+ 41, 0, 10, 8, 21, 34, 5, 5, 60, 18, 5, 1, 29, 42, 26, 2, 16, 0, 27, 9, 43, 28, 7, 0, 0, 1, 4, 0, 0,255, 0, 0,255,255,255, 0,255, 0, 0, 0, 0,255, 0, 0, 0, 0, 0, 0, 0, 0,255,255,255, 0, 0, 0, 0, 0,255, // á,
+ 24, 0, 1, 2, 0, 0, 0, 0, 7, 0, 0, 0, 3, 1, 0, 0, 0, 0, 2, 0, 5, 0, 1, 0, 0, 0, 0,255, 0,255, 0, 0, 0,255, 0,255, 0, 0, 0, 2, 0,255, 0,255, 0, 0, 0, 0,255, 0,255,255,255,255,255, 0,255, 0,255, // â,
+ 0, 0, 0, 1, 2, 3, 0, 1, 2, 12, 0, 0, 1, 7, 29, 4, 1,255, 11, 66, 11, 0, 1, 0, 0, 0, 0,255, 0,255,255,255, 0, 0, 0,255,255,127,255,255,255,255,255, 0, 0,255, 0, 0,255,255, 0,255,255,255,255,255,255,255,255, // ã,
+ 134, 1, 11, 0, 25, 6, 15, 11, 61, 24,123, 95,114, 68, 53, 1, 49, 0, 60, 98,198, 0, 88, 29, 0, 6, 12, 0, 0,255, 0,255, 0, 0,118, 0,255, 0,255, 0,255, 0,255, 0,255,255, 0,255,255, 0,255, 2,255,255,255, 0, 0, 0,255, // ä,
+ 156, 0, 12, 14, 19, 3, 12, 47, 17, 3, 12, 5, 30, 47, 22, 0,205, 0,184, 70, 19, 0, 22, 8, 0, 6, 1,255, 0,255,255, 0,255, 0, 0, 0, 0, 0,255, 0,255, 0,255, 0, 0,255,255,255,255,255,255, 0, 0,255,255,255,255,255,255, // å,
+ 26, 0, 7, 0, 4, 0, 23, 8, 15, 0, 18, 19, 56, 23, 24, 0, 9, 0, 82, 37, 24, 0, 71, 0, 0, 0, 0,255, 0,255,255, 0,255,255, 0, 0, 0, 0,255, 0,255,255,255, 0,255,255, 0,255,255,255,255, 0, 0,255,255,255,255, 0,255, // æ,
+ 17,112, 0, 2, 0, 15, 0, 0, 0, 35, 0, 0, 2, 0, 59, 9, 1, 0, 36, 0, 0, 8, 0, 0, 0, 0, 0,255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,255,255, // ç,
+ 254, 0, 9, 14, 20, 0, 15, 6, 70,144, 14, 45, 47, 92, 16, 3,123, 0, 38, 23,115, 52, 22, 42, 2, 80, 19,255, 0,255, 0, 0,255,255, 0,255,255, 0, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0,255, 0,255,255,255, 0, 0, 0, 1,255,255, // è,
+ 152, 2, 19, 24, 85, 0, 29, 23, 26, 25, 2, 9, 43, 60, 62, 1, 32, 0,122, 45,169, 15, 13, 30, 7, 4, 8, 0, 0,255, 0, 0, 0, 0, 0,255, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 1,255, 0, 0, 0, 0,255, 0, 0, 0, 0, 0, 0, // é,
+ 5, 0, 0, 3, 7, 0, 0, 10, 2, 3, 0, 26, 6, 6, 20, 1, 2, 0, 20, 1, 11, 5, 5, 2, 0, 0, 1,255, 0,255,255,255, 0,255,255,255,255, 0, 0, 0, 0, 0,255, 0, 0, 0, 0,255, 0, 0,255,255,255, 0,255, 0, 0, 0,255, // ê,
+ 36, 2, 23, 15, 36,143, 5, 23, 52, 52, 66, 48, 92, 57,216, 10,125, 35, 89, 58,254, 9, 24, 14, 0, 0, 8,255, 0,255, 0,255,255,255, 0, 0,255, 1, 0, 0, 0, 0, 0,255, 0, 0, 0,255,255,255, 0, 0, 0, 0,255, 0, 0, 0,255, // ë,
+ 12, 0, 1, 4, 6, 0, 3, 21, 10, 0, 0, 0, 18, 8, 4, 0, 1, 0, 65, 35, 8, 3, 0, 0, 0, 0, 0,255, 0,255, 0, 0,255,255,255,255,255,255, 0, 0, 0,255, 0, 0, 0,255, 0, 0,255, 0,255,255,255, 0,255,255, 0, 0,255, // ì,
+ 40, 72, 7, 10, 16, 2, 23, 10, 34, 0, 0, 1, 34, 15, 21, 1, 3, 0,203, 28, 58, 23, 11, 0, 10, 0, 2, 0, 0, 0, 0, 0, 0,255, 0,255,255, 0, 0, 0, 0,255, 0, 0,255,255, 1,255, 0,255,255, 0,255,255, 0,255, 2, 0,255, // í,
+ 6, 5, 1, 9, 5, 0, 0, 0, 22, 0, 9, 8, 8, 6, 9, 1, 10, 0, 20, 6,182, 0, 13, 0, 0, 24, 1,255, 0,255,255,255, 0, 0,255, 0,255, 0,255, 0, 0, 0, 0, 0, 0, 0, 0, 0,255, 0,255,255,255,255,255, 0,255,255,255, // î,
+ 0, 6, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 0,255,255, 0, 0, 0, 0,255, 0,255, 0, 0, 0, 0, 0, 0,255, 0, 0, 0, 0,255, 0, 0, 0, 0,255,255, 0, 0, 0,255,255, // ï,
+ 0,254, 0, 0, 0, 26, 0, 0, 0, 61, 0, 0, 0, 0, 0, 14, 0, 0, 0, 0, 0, 25, 0, 0, 0, 0, 0,255,255,255, 0, 0, 0, 0, 0, 0,255,255, 0, 0, 0,255, 0, 1, 0, 0, 0,255, 0, 0, 0, 0, 0, 0, 0,255, 0,255,255, // ñ,
+ 20, 0, 56, 43, 8,162, 14, 3, 23, 19, 2,118, 31, 26, 46, 0, 20, 0, 23, 6, 24, 19, 6, 21, 5, 27, 63,255, 0,255, 0, 0,255,255,255,255,255, 3, 0,255,255,255, 0, 0,255, 0, 0, 0, 0,255, 0,255,255, 0,255,255, 0,255,255, // ò,
+ 67, 0, 12, 15, 9, 7, 8, 66, 13,254, 3, 23, 14, 16, 16, 0, 8, 0, 29, 11, 26, 0, 5, 5, 1, 10, 13,255, 0,255,255, 0,255, 0, 0,255,255, 1,255, 0,255,255, 0, 0,255, 0, 1, 0, 0, 0, 0,255,255,255, 0,255,255, 0,255, // ó,
+ 18, 3, 3, 12, 1, 0, 2, 0, 7, 0, 1, 0, 2, 2, 8, 0, 6, 0, 6, 7, 4, 0, 2, 0, 0, 0, 1,255, 0, 0,255, 0, 0,255,255,255, 0, 0, 0, 0, 0,255,255, 0, 0, 0, 0, 0, 0, 0,255,255,255,255, 0, 0,255,255,255, // ô,
+ 29, 2, 0, 0, 0, 0, 0, 0, 5, 2, 22, 30, 25, 38, 19, 0, 33,255, 4, 39, 24, 0, 88, 0, 0, 0, 0,255, 0,255,255, 0,255, 0,255,255,255, 36,255,255,255,255,255, 0,255,255, 0,255, 0, 0, 6, 0,255,255,255, 0, 0, 0,255, // õ,
+ 44, 0, 33, 0, 25, 0,142, 5, 46, 10, 25, 32, 26, 13, 6, 0, 3, 0, 30, 8, 35, 0, 25, 5, 0, 44, 7, 0, 0,255,255, 0,255,255, 73, 0,255, 0, 0, 0,255,255,255,255,255, 0, 0,255, 0, 0, 0, 39, 0,255,255,255, 0, 0, 0, // ö,
+ 52, 0, 21, 0, 57, 0,119, 12, 47, 3, 59, 33, 45, 15, 12, 0, 3, 0, 52, 82, 49, 1, 11, 0, 0, 0, 0, 0,255, 0,255,255,255,255,255, 0, 0, 0,255, 0,255,255,255, 0,255,255, 0,255,255,255,255, 0, 0,255,255,255,255,255, 0, // ø,
+ 25, 0, 4, 3, 53, 0, 0, 2, 12, 72, 0, 0, 30, 0, 0,254, 0, 0, 6, 3, 3, 0, 0, 0, 0, 0, 0,255, 0,255, 0,255, 0,255,255,255,255, 0, 0, 0, 0,255, 0,255,255,255,255, 0,255, 0, 0,255,255, 0, 0, 0, 0, 0, 0, // ù,
+ 19, 2, 1, 7, 9, 1, 12, 5, 9, 41, 1, 0, 10, 7, 9, 0, 8, 0, 12, 28, 8, 0, 0, 0, 0, 1, 0,255, 0,255,255, 0,255,255,255,255, 0, 0,255, 0,255,255,255, 0,255,255, 0, 0, 0,255, 0,255,255, 0, 0,255,255, 0,255, // ú,
+ 0, 0, 0, 0, 1, 5, 0, 0, 1, 0, 0, 0, 0, 0, 0, 45, 0, 0, 3, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,255,255,255, 0,255,255,255,255, 0,255, 0,255,255,255, 0, 0,255,255,255,255, 0,255,255,255, 0,255, 0, 0,255, 0, // û,
+ 95, 2, 19, 0, 6, 2,121, 9, 15, 1, 5, 44, 18, 26, 7, 0, 11, 2, 68, 49, 20, 0, 2, 17, 0, 0, 6, 0, 0,255, 0,255,255,255, 0,255,255, 0,255, 0,255, 0,255,255,255, 0, 0,255,255,255, 0, 0,255, 0, 0, 0, 31, 0, 0, // ü,
+ 1, 1, 0, 0, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,255, 0, 0, 0, 0, 0, 0, 0, 0,255, 0, 0,255,255, 0, 0,255, 0,255, 0,255,255,255,255, 0, 0, 0, 0,255, 0, 0, 0, 0, 0,255, // ž,
+ 0, 0, 0, 0, 0, 0,255, 0, 0,255, 0, 0, 0, 0, 0, 0, 0,255, 0, 0, 0, 0, 0, 0,255,255, 0,255,255,255,255,255,255, 0,255, 0,255,255,255,255,255,255,255,255,255,255,255,255,255, 0, 0,255, 0,255,255,255, 0, 0, 0, // ÿ,
+ // , a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z, ß, š, œ, à, á, â, ã, ä, å, æ, ç, è, é, ê, ë, ì, í, î, ï, ñ, ò, ó, ô, õ, ö, ø, ù, ú, û, ü, ž, ÿ,
+
+ });
+ // clang-format on
+ };
+
+ namespace class_size {
+ constexpr std::size_t cyrillic_ascii = 2;
+ constexpr std::size_t cyrillic_non_ascii = 44;
+ constexpr std::size_t western_ascii = 27;
+ constexpr std::size_t western_non_ascii = 32;
+ }
+
+ constexpr std::size_t ASCII_DIGIT = 100;
+
+ struct ByteScore {
+ const Encoding encoding;
+ const std::array<ubyte, 128>& lower;
+ const std::array<ubyte, 128>& upper;
+ const std::span<const ubyte> probabilities;
+ const std::size_t ascii;
+ const std::size_t non_ascii;
+
+ static inline constexpr std::optional<std::size_t> compute_index(std::size_t x, std::size_t y, std::size_t ascii_classes, std::size_t non_ascii_classes) {
+ if (x == 0 && y == 0) {
+ return std::nullopt;
+ }
+
+ if (x < ascii_classes && y < ascii_classes) {
+ return std::nullopt;
+ }
+
+ if (y >= ascii_classes) {
+ return (ascii_classes * non_ascii_classes) + (ascii_classes + non_ascii_classes) * (y - ascii_classes) + x;
+ }
+
+ return y * non_ascii_classes + x - ascii_classes;
+ }
+
+ inline constexpr cbyte classify(cbyte byte) const {
+ cbyte high = byte >> 7;
+ cbyte low = byte & 0x7F;
+ if (high == 0) {
+ return lower[low];
+ }
+
+ return upper[low];
+ }
+
+ inline constexpr bool is_latin_alphabetic(cbyte caseless_class) const {
+ return caseless_class > 0 && caseless_class < (ascii + non_ascii);
+ }
+
+ inline constexpr bool is_non_latin_alphabetic(cbyte caseless_class) const {
+ return caseless_class > 1 && caseless_class < (ascii + non_ascii);
+ }
+
+ inline constexpr int64_t score(cbyte current_class, cbyte previous_class) const {
+ constexpr std::size_t IMPLAUSABILITY_PENALTY = -220;
+
+ constexpr std::size_t PLAUSIBLE_NEXT_TO_ALPHABETIC_ON_EITHER_SIDE = 0;
+ constexpr std::size_t IMPLAUSIBLE_NEXT_TO_ALPHABETIC_ON_EITHER_SIDE = 1;
+ constexpr std::size_t IMPLAUSIBLE_BEFORE_ALPHABETIC = 2;
+ constexpr std::size_t IMPLAUSIBLE_AFTER_ALPHABETIC = 3;
+ constexpr std::size_t PLAUSIBLE_NEXT_TO_NON_ASCII_ALPHABETIC_ON_EITHER_SIDE = 4;
+ constexpr std::size_t PLAUSIBLE_NEXT_TO_ASCII_ALPHABETIC_ON_EITHER_SIDE = 5;
+
+ std::size_t stored_boundary = ascii + non_ascii;
+ if (current_class < stored_boundary) {
+ if (previous_class < stored_boundary) {
+ if (auto index = compute_index(previous_class, current_class, ascii, non_ascii); index) {
+ ubyte b = probabilities[index.value()];
+ if (b == 255) {
+ return IMPLAUSABILITY_PENALTY;
+ }
+ return b;
+ }
+ return 0;
+ }
+
+ if (current_class == 0 || current_class == ASCII_DIGIT) {
+ return 0;
+ }
+
+ std::size_t previous_unstored = previous_class - stored_boundary;
+ switch (previous_unstored) {
+ case PLAUSIBLE_NEXT_TO_ALPHABETIC_ON_EITHER_SIDE:
+ case IMPLAUSIBLE_AFTER_ALPHABETIC:
+ return 0;
+ case IMPLAUSIBLE_NEXT_TO_ALPHABETIC_ON_EITHER_SIDE:
+ case IMPLAUSIBLE_BEFORE_ALPHABETIC:
+ return IMPLAUSABILITY_PENALTY;
+ case PLAUSIBLE_NEXT_TO_NON_ASCII_ALPHABETIC_ON_EITHER_SIDE:
+ if (current_class < ascii) {
+ return IMPLAUSABILITY_PENALTY;
+ }
+ return 0;
+ case PLAUSIBLE_NEXT_TO_ASCII_ALPHABETIC_ON_EITHER_SIDE:
+ if (current_class < ascii) {
+ return 0;
+ }
+ return IMPLAUSABILITY_PENALTY;
+ default:
+ assert(previous_class == ASCII_DIGIT);
+ return 0;
+ }
+ }
+
+ if (previous_class < stored_boundary) {
+ if (previous_class == 0 || previous_class == ASCII_DIGIT) {
+ return 0;
+ }
+
+ std::size_t current_unstored = current_class - stored_boundary;
+ switch (current_unstored) {
+ case PLAUSIBLE_NEXT_TO_ALPHABETIC_ON_EITHER_SIDE:
+ case IMPLAUSIBLE_BEFORE_ALPHABETIC:
+ return 0;
+ case IMPLAUSIBLE_NEXT_TO_ALPHABETIC_ON_EITHER_SIDE:
+ case IMPLAUSIBLE_AFTER_ALPHABETIC:
+ return IMPLAUSABILITY_PENALTY;
+ case PLAUSIBLE_NEXT_TO_NON_ASCII_ALPHABETIC_ON_EITHER_SIDE:
+ if (previous_class < ascii) {
+ return IMPLAUSABILITY_PENALTY;
+ }
+ return 0;
+ case PLAUSIBLE_NEXT_TO_ASCII_ALPHABETIC_ON_EITHER_SIDE:
+ if (previous_class < ascii) {
+ return 0;
+ }
+ return IMPLAUSABILITY_PENALTY;
+ default:
+ assert(current_class == ASCII_DIGIT);
+ return 0;
+ }
+ }
+
+ if (current_class == ASCII_DIGIT || previous_class == ASCII_DIGIT) {
+ return 0;
+ }
+
+ return IMPLAUSABILITY_PENALTY;
+ }
+ };
+
+ enum class ScoreIndex {
+ Windows1251,
+ Windows1252
+ };
+
+ static constexpr std::array byte_scores {
+ ByteScore {
+ .encoding = Encoding::Windows1251,
+ .lower = DetectorData::non_latin_ascii,
+ .upper = DetectorData::windows_1251,
+ .probabilities = DetectorData::cyrillic,
+ .ascii = class_size::cyrillic_ascii,
+ .non_ascii = class_size::cyrillic_non_ascii },
+ ByteScore {
+ .encoding = Encoding::Windows1252,
+ .lower = DetectorData::latin_ascii,
+ .upper = DetectorData::windows_1252,
+ .probabilities = DetectorData::western,
+ .ascii = class_size::western_ascii,
+ .non_ascii = class_size::western_non_ascii }
+ };
+
+ constexpr const ByteScore& get_byte_score(ScoreIndex index) {
+ return byte_scores[static_cast<std::underlying_type_t<ScoreIndex>>(index)];
+ }
+
+ struct Utf8Canidate {
+ std::optional<int64_t> read(const std::span<const cbyte>& buffer);
+ };
+
+ struct AsciiCanidate {
+ std::optional<int64_t> read(const std::span<const cbyte>& buffer);
+ };
+
+ struct NonLatinCasedCanidate {
+ enum class CaseState {
+ Space,
+ Upper,
+ Lower,
+ UpperLower,
+ AllCaps,
+ Mix,
+ };
+
+ const ByteScore& score_data;
+ cbyte prev {};
+ CaseState case_state = CaseState::Space;
+ bool prev_ascii = true;
+ uint64_t current_word_len {};
+ uint64_t longest_word {};
+ bool ibm866 = false;
+ bool prev_was_a0 = false;
+
+ std::optional<int64_t> read(const std::span<const cbyte>& buffer);
+ };
+
+ struct LatinCanidate {
+ enum class CaseState {
+ Space,
+ Upper,
+ Lower,
+ AllCaps,
+ };
+
+ enum class OrdinalState {
+ Other,
+ Space,
+ PeriodAfterN,
+ OrdinalExpectingSpace,
+ OrdinalExpectingSpaceUndoImplausibility,
+ OrdinalExpectingSpaceOrDigit,
+ OrdinalExpectingSpaceOrDigitUndoImplausibily,
+ UpperN,
+ LowerN,
+ FeminineAbbreviationStartLetter,
+ Digit,
+ Roman,
+ Copyright,
+ };
+
+ const ByteScore& score_data;
+ cbyte prev {};
+ CaseState case_state = CaseState::Space;
+ uint32_t prev_non_ascii {};
+ OrdinalState ordinal_state = OrdinalState::Space; // Used only when `windows1252 == true`
+ bool windows1252;
+
+ constexpr LatinCanidate(const ByteScore& data) : score_data(data) {
+ windows1252 = data.encoding == Encoding::Windows1252;
+ }
+
+ std::optional<int64_t> read(const std::span<const cbyte>& buffer);
+ };
+
+ using InnerCanidate = std::variant<NonLatinCasedCanidate, LatinCanidate, Utf8Canidate, AsciiCanidate>;
+
+ template<class... Ts>
+ struct overloaded : Ts... {
+ using Ts::operator()...;
+ };
+
+ template<class... Ts>
+ overloaded(Ts...) -> overloaded<Ts...>;
+
+ struct Canidate {
+ InnerCanidate inner;
+ std::optional<int64_t> score_value;
+
+ template<typename CanidateT>
+ static constexpr Canidate create_canidate() {
+ return {
+ .inner = CanidateT(),
+ .score_value = 0
+ };
+ }
+
+ template<typename CanidateT>
+ static constexpr Canidate create_canidate(const ByteScore& score) {
+ return {
+ .inner = CanidateT { score },
+ .score_value = 0
+ };
+ }
+
+ static constexpr Canidate new_utf8() {
+ return create_canidate<Utf8Canidate>();
+ }
+
+ static constexpr Canidate new_ascii() {
+ return create_canidate<AsciiCanidate>();
+ }
+
+ static constexpr Canidate new_latin(ScoreIndex index) {
+ return create_canidate<LatinCanidate>(get_byte_score(index));
+ }
+
+ static constexpr Canidate new_non_latin_cased(ScoreIndex index) {
+ return create_canidate<NonLatinCasedCanidate>(get_byte_score(index));
+ }
+
+ constexpr std::optional<int64_t> score(const std::span<const cbyte>& buffer, std::size_t encoding, bool expectation_is_valid) {
+ if (auto old_score = score_value) {
+ auto new_score = std::visit([&](auto& inner) {
+ return inner.read(buffer);
+ },
+ inner);
+ if (new_score) {
+ score_value = old_score.value() + new_score.value();
+ } else {
+ score_value = std::nullopt;
+ }
+ }
+
+ if (auto nlcc = std::get_if<NonLatinCasedCanidate>(&inner)) {
+ if (nlcc->longest_word < 2) {
+ return std::nullopt;
+ }
+ }
+ return score_value;
+ }
+
+ constexpr Encoding encoding() const {
+ return std::visit(
+ overloaded {
+ [](const Utf8Canidate& canidate) {
+ return Encoding::Utf8;
+ },
+ [](const AsciiCanidate& canidate) {
+ return Encoding::Ascii;
+ },
+ [](const LatinCanidate& canidate) {
+ return canidate.score_data.encoding;
+ },
+ [](const NonLatinCasedCanidate& canidate) {
+ return canidate.score_data.encoding;
+ } },
+ inner);
+ }
+ };
+
+ struct Detector {
+ std::vector<Canidate> canidates {
+ Canidate::new_ascii(),
+ Canidate::new_utf8(),
+ Canidate::new_latin(ScoreIndex::Windows1252),
+ Canidate::new_non_latin_cased(ScoreIndex::Windows1251),
+ };
+
+ Encoding default_fallback = Encoding::Unknown;
+
+ constexpr std::pair<Encoding, bool> detect_assess(std::span<const cbyte> buffer, bool allow_utf8 = true) {
+ int64_t max = 0;
+ Encoding encoding = default_fallback; // Presumes fallback, defaults to Unknown encoding if unknown (which skips conversion)
+ std::size_t i = 0;
+ for (Canidate& canidate : canidates) {
+ if (!allow_utf8 && canidate.encoding() == Encoding::Utf8) {
+ continue;
+ }
+
+ if (auto score = canidate.score(buffer, i, false)) {
+ switch (canidate.encoding()) {
+ using enum Encoding;
+ case Ascii:
+ case Utf8:
+ return { canidate.encoding(), true };
+ default: break;
+ }
+
+ auto value = score.value();
+ if (value > max) {
+ max = value;
+ encoding = canidate.encoding();
+ }
+ }
+ i++;
+ }
+ return { encoding, max >= 0 };
+ }
+
+ constexpr Encoding detect(std::span<const cbyte> buffer, bool allow_utf8 = true) {
+ return detect_assess(buffer, allow_utf8).first;
+ }
+
+ template<typename BufferEncoding>
+ std::pair<Encoding, bool> detect_assess(const lexy::buffer<BufferEncoding, void>& buffer, bool allow_utf8 = true) {
+ auto span = std::span<const cbyte>(buffer.data(), buffer.size());
+ return detect_assess(span);
+ }
+
+ template<typename BufferEncoding>
+ constexpr Encoding detect(const lexy::buffer<BufferEncoding, void>& buffer, bool allow_utf8 = true) {
+ return detect_assess(buffer, allow_utf8).first;
+ }
+ };
+} \ No newline at end of file