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
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
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
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
/*
* MIT License
*
* Copyright (c) 2017-2019 Mikhail Pilin
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#pragma once
#include <cstdint>
#include <utility>
#include <stdexcept>
#include "base/result.h"
namespace ww898 {
namespace utf {
// Supported combinations:
// 0xxx_xxxx
// 110x_xxxx 10xx_xxxx
// 1110_xxxx 10xx_xxxx 10xx_xxxx
// 1111_0xxx 10xx_xxxx 10xx_xxxx 10xx_xxxx
// 1111_10xx 10xx_xxxx 10xx_xxxx 10xx_xxxx 10xx_xxxx
// 1111_110x 10xx_xxxx 10xx_xxxx 10xx_xxxx 10xx_xxxx 10xx_xxxx
struct utf8 final
{
static size_t const max_unicode_symbol_size = 4;
static size_t const max_supported_symbol_size = 6;
static uint32_t const max_supported_code_point = 0x7FFFFFFF;
using char_type = uint8_t;
template<typename PeekFn>
static Result<size_t, const char *> char_size(PeekFn && peek_fn)
{
const std::pair<char_type, size_t> peek_res = std::forward<PeekFn>(peek_fn)();
const auto ch0 = peek_res.first;
const auto remaining = peek_res.second;
size_t retval = 0;
if (ch0 < 0x80) { // 0xxx_xxxx
retval = 1;
} else if (ch0 < 0xC0) {
return Err("The utf8 first char in sequence is incorrect");
} else if (ch0 < 0xE0) { // 110x_xxxx 10xx_xxxx
retval = 2;
} else if (ch0 < 0xF0) { // 1110_xxxx 10xx_xxxx 10xx_xxxx
retval = 3;
} else if (ch0 < 0xF8) { // 1111_0xxx 10xx_xxxx 10xx_xxxx 10xx_xxxx
retval = 4;
} else if (ch0 < 0xFC) { // 1111_10xx 10xx_xxxx 10xx_xxxx 10xx_xxxx 10xx_xxxx
retval = 5;
} else if (ch0 < 0xFE) { // 1111_110x 10xx_xxxx 10xx_xxxx 10xx_xxxx 10xx_xxxx 10xx_xxxx
retval = 6;
} else {
return Err("The utf8 first char in sequence is incorrect");
}
if (retval - 1 > remaining) {
return Err("Truncated utf8 sequence");
}
return Ok(retval);
}
template<typename ReadFn>
static uint32_t read(ReadFn && read_fn)
{
char_type const ch0 = read_fn();
if (ch0 < 0x80) // 0xxx_xxxx
return ch0;
if (ch0 < 0xC0)
throw std::runtime_error("The utf8 first char in sequence is incorrect");
if (ch0 < 0xE0) // 110x_xxxx 10xx_xxxx
{
char_type const ch1 = read_fn(); if (ch1 >> 6 != 2) goto _err;
return (ch0 << 6) + ch1 - 0x3080;
}
if (ch0 < 0xF0) // 1110_xxxx 10xx_xxxx 10xx_xxxx
{
char_type const ch1 = read_fn(); if (ch1 >> 6 != 2) goto _err;
char_type const ch2 = read_fn(); if (ch2 >> 6 != 2) goto _err;
return (ch0 << 12) + (ch1 << 6) + ch2 - 0xE2080;
}
if (ch0 < 0xF8) // 1111_0xxx 10xx_xxxx 10xx_xxxx 10xx_xxxx
{
char_type const ch1 = read_fn(); if (ch1 >> 6 != 2) goto _err;
char_type const ch2 = read_fn(); if (ch2 >> 6 != 2) goto _err;
char_type const ch3 = read_fn(); if (ch3 >> 6 != 2) goto _err;
return (ch0 << 18) + (ch1 << 12) + (ch2 << 6) + ch3 - 0x3C82080;
}
if (ch0 < 0xFC) // 1111_10xx 10xx_xxxx 10xx_xxxx 10xx_xxxx 10xx_xxxx
{
char_type const ch1 = read_fn(); if (ch1 >> 6 != 2) goto _err;
char_type const ch2 = read_fn(); if (ch2 >> 6 != 2) goto _err;
char_type const ch3 = read_fn(); if (ch3 >> 6 != 2) goto _err;
char_type const ch4 = read_fn(); if (ch4 >> 6 != 2) goto _err;
return (ch0 << 24) + (ch1 << 18) + (ch2 << 12) + (ch3 << 6) + ch4 - 0xFA082080;
}
if (ch0 < 0xFE) // 1111_110x 10xx_xxxx 10xx_xxxx 10xx_xxxx 10xx_xxxx 10xx_xxxx
{
char_type const ch1 = read_fn(); if (ch1 >> 6 != 2) goto _err;
char_type const ch2 = read_fn(); if (ch2 >> 6 != 2) goto _err;
char_type const ch3 = read_fn(); if (ch3 >> 6 != 2) goto _err;
char_type const ch4 = read_fn(); if (ch4 >> 6 != 2) goto _err;
char_type const ch5 = read_fn(); if (ch5 >> 6 != 2) goto _err;
return (ch0 << 30) + (ch1 << 24) + (ch2 << 18) + (ch3 << 12) + (ch4 << 6) + ch5 - 0x82082080;
}
throw std::runtime_error("The utf8 first char in sequence is incorrect");
_err: throw std::runtime_error("The utf8 slave char in sequence is incorrect");
}
template<typename WriteFn>
static void write(uint32_t const cp, WriteFn && write_fn)
{
if (cp < 0x80) // 0xxx_xxxx
write_fn(static_cast<char_type>(cp));
else if (cp < 0x800) // 110x_xxxx 10xx_xxxx
{
write_fn(static_cast<char_type>(0xC0 | cp >> 6));
goto _1;
}
else if (cp < 0x10000) // 1110_xxxx 10xx_xxxx 10xx_xxxx
{
write_fn(static_cast<char_type>(0xE0 | cp >> 12));
goto _2;
}
else if (cp < 0x200000) // 1111_0xxx 10xx_xxxx 10xx_xxxx 10xx_xxxx
{
write_fn(static_cast<char_type>(0xF0 | cp >> 18));
goto _3;
}
else if (cp < 0x4000000) // 1111_10xx 10xx_xxxx 10xx_xxxx 10xx_xxxx 10xx_xxxx
{
write_fn(static_cast<char_type>(0xF8 | cp >> 24));
goto _4;
}
else if (cp < 0x80000000) // 1111_110x 10xx_xxxx 10xx_xxxx 10xx_xxxx 10xx_xxxx 10xx_xxxx
{
write_fn(static_cast<char_type>(0xFC | cp >> 30));
goto _5;
}
else
throw std::runtime_error("Tool large UTF8 code point");
return;
_5: write_fn(static_cast<char_type>(0x80 | (cp >> 24 & 0x3F)));
_4: write_fn(static_cast<char_type>(0x80 | (cp >> 18 & 0x3F)));
_3: write_fn(static_cast<char_type>(0x80 | (cp >> 12 & 0x3F)));
_2: write_fn(static_cast<char_type>(0x80 | (cp >> 6 & 0x3F)));
_1: write_fn(static_cast<char_type>(0x80 | (cp & 0x3F)));
}
};
}}
|
