blob: 4cba14fb03d9fe5812b80106c6530fc82f6ff9ea (
plain) (
blame)
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
|
/*
Copyright 2021 Gabriel Jensen
This file is part of u8c.
u8c is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
u8c is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with u8c.
If not, see <https://www.gnu.org/licenses/>.
*/
# include <assert.h>
# include <stdbool.h>
# include <stddef.h>
# include <stdint.h>
# include <u8c/SIZE_C.h>
# include <u8c/err.h>
# include <u8c/str.h>
# include <u8c/u8.h>
# include <uchar.h>
struct u8c_u8dec_tuple u8c_u8dec(unsigned char const * const restrict _in) {
struct u8c_u8dec_tuple ret = {
.stat = false,
};
register size_t insz = SIZE_C(0x0);
for(register size_t n = SIZE_C(0x0);n <= SIZE_MAX;ret.strsz += SIZE_C(0x1)) { /* First pass: get size of input array and determine size of output array. */
register unsigned char const tmp = _in[n];
if(tmp == UINT8_C(0x0)) { /* Null-terminator: end of string has been reached. */
insz = n;
goto nottoobig;
}
if(tmp >= UINT8_C(0b11111000)) { /* Too big. */
u8c_seterr(u8c_errtyp_u8oor,U"u8c_u8dec: Character out of range (too big).");
ret.stat = true;
return ret;
}
if(tmp >= UINT8_C(0b11110000)) { /* Four byte. */
n += SIZE_C(0x4);
continue;
}
if(tmp >= UINT8_C(0b11100000)) { /* Three bytes. */
n += SIZE_C(0x3);
continue;
}
if(tmp >= UINT8_C(0b11000000)) { /* Two bytes. */
n += SIZE_C(0x2);
continue;
}
/* One byte. */
n += SIZE_C(0x1);
}
/* Input is not null-terminated. */
u8c_seterr(u8c_errtyp_untermin,U"u8c_u8dec: Unterminated input.");
ret.stat = true;
return ret;
nottoobig:;
uint_least32_t * out = NULL;
{
struct u8c_stralloc_tuple const tuple = u8c_stralloc(ret.strsz + SIZE_C(0x1));
if(tuple.stat) {
ret.stat = true;
return ret;
}
out = tuple.str;
}
for(register size_t n = SIZE_C(0x0),outn = SIZE_C(0x0);n < insz;outn += SIZE_C(0x1)) { /* Second pass: decode UTF-8. */
if(_in[n] >= UINT8_C(0b11110000)) { /* Four bytes. */
uint_least32_t codep = (_in[n] ^ UINT32_C(0b11110000)) << UINT32_C(0x12);
n += SIZE_C(0x1);
codep += (_in[n] ^ UINT32_C(0b10000000)) << UINT32_C(0xC);
n += SIZE_C(0x1);
codep += (_in[n] ^ UINT32_C(0b10000000)) << UINT32_C(0x6);
n += SIZE_C(0x1);
codep += (uint_least32_t)(_in[n]) ^ SIZE_C(0b10000000);
n += SIZE_C(0x1);
out[outn] = codep;
continue;
}
if(_in[n] >= UINT8_C(0b11100000)) { /* Three bytes. */
uint_least32_t codep = (_in[n] ^ UINT32_C(0b11100000)) << UINT32_C(0xC);
n += SIZE_C(0x1);
codep += (_in[n] ^ UINT32_C(0b10000000)) << UINT32_C(0x6);
n += SIZE_C(0x1);
codep += _in[n] ^ UINT32_C(0b10000000);
n += SIZE_C(0x1);
out[outn] = codep;
continue;
}
if(_in[n] >= UINT8_C(0b11000000)) { /* Two bytes. */
uint_least32_t codep = (_in[n] ^ UINT32_C(0b11000000)) << UINT32_C(0x6);
n += SIZE_C(0x1);
codep += _in[n] ^ UINT32_C(0b10000000);
n += SIZE_C(0x1);
out[outn] = codep;
continue;
}
/* One byte. */
out[outn] = (uint_least32_t)(_in[n]);
n += SIZE_C(0x1);
continue;
}
ret.str = out;
return ret;
}
|
