summaryrefslogtreecommitdiff
path: root/src/utf8.c
blob: e3f8dd3c2c278bb8b937808185459df229f63334 (plain)
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
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>

#include "stmd.h"

static const int8_t utf8proc_utf8class[256] = {
	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, 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, 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, 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, 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, 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, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
	3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
	4, 4, 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0 };

ssize_t utf8proc_charlen(const uint8_t *str, ssize_t str_len)
{
	ssize_t length, i;

	if (!str_len)
		return 0;

	length = utf8proc_utf8class[str[0]];

	if (!length)
		return -1;

	if (str_len >= 0 && length > str_len)
		return -1;

	for (i = 1; i < length; i++) {
		if ((str[i] & 0xC0) != 0x80)
			return -1;
	}

	return length;
}

ssize_t utf8proc_iterate(const uint8_t *str, ssize_t str_len, int32_t *dst)
{
	ssize_t length;
	int32_t uc = -1;

	*dst = -1;
	length = utf8proc_charlen(str, str_len);
	if (length < 0)
		return -1;

	switch (length) {
		case 1:
			uc = str[0];
			break;
		case 2:
			uc = ((str[0] & 0x1F) <<  6) + (str[1] & 0x3F);
			if (uc < 0x80) uc = -1;
			break;
		case 3:
			uc = ((str[0] & 0x0F) << 12) + ((str[1] & 0x3F) <<  6)
				+ (str[2] & 0x3F);
			if (uc < 0x800 || (uc >= 0xD800 && uc < 0xE000) ||
					(uc >= 0xFDD0 && uc < 0xFDF0)) uc = -1;
			break;
		case 4:
			uc = ((str[0] & 0x07) << 18) + ((str[1] & 0x3F) << 12)
				+ ((str[2] & 0x3F) <<  6) + (str[3] & 0x3F);
			if (uc < 0x10000 || uc >= 0x110000) uc = -1;
			break;
	}

	if (uc < 0 || ((uc & 0xFFFF) >= 0xFFFE))
		return -1;

	*dst = uc;
	return length;
}

void utf8_encode_char(int32_t uc, gh_buf *buf)
{
	char dst[4];
	int len = 0;

	if (uc < 0x00) {
		assert(false);
	} else if (uc < 0x80) {
		dst[0] = uc;
		len = 1;
	} else if (uc < 0x800) {
		dst[0] = 0xC0 + (uc >> 6);
		dst[1] = 0x80 + (uc & 0x3F);
		len = 2;
	} else if (uc == 0xFFFF) {
		dst[0] = 0xFF;
		return 1;
	} else if (uc == 0xFFFE) {
		dst[0] = 0xFE;
		len = 1;
	} else if (uc < 0x10000) {
		dst[0] = 0xE0 + (uc >> 12);
		dst[1] = 0x80 + ((uc >> 6) & 0x3F);
		dst[2] = 0x80 + (uc & 0x3F);
		len = 3;
	} else if (uc < 0x110000) {
		dst[0] = 0xF0 + (uc >> 18);
		dst[1] = 0x80 + ((uc >> 12) & 0x3F);
		dst[2] = 0x80 + ((uc >> 6) & 0x3F);
		dst[3] = 0x80 + (uc & 0x3F);
		len = 4;
	} else {
		assert(false);
	}

	gh_buf_put(buf, dst, len);
}

void utf8proc_case_fold(gh_buf *dest, const unsigned char *str, int len)
{
	int32_t c;

#define bufpush(x) \
	utf8proc_encode_char(x, dest)

	while (len > 0) {
		ssize_t char_len = utf8proc_iterate(str, len, &c);

		if (char_len < 0) {
			bufpush(0xFFFD);
			continue;
		}

#include "case_fold_switch.inc"

		str += char_len;
		len -= char_len;
	}
}