summaryrefslogtreecommitdiff
path: root/utf8.h
blob: 786b13f80ba797f609198d9c90556ce608ad442c (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
#ifndef UTF8_UTIL_H
#define UTF8_UTIL_H
/**
 * UTF-8 utility functions
 *
 * (c) 2010 Steve Bennett <steveb@workware.net.au>
 *
 * See LICENCE for licence details.
 */
#include <jim-config.h>

/**
 * Converts the given unicode codepoint (0 - 0xffff) to utf-8
 * and stores the result at 'p'.
 *
 * Returns the number of utf-8 characters (1-3).
 */
int utf8_fromunicode(char *p, unsigned short uc);

#ifndef JIM_UTF8
#include <ctype.h>

/* No utf-8 support. 1 byte = 1 char */
#define utf8_strlen(S, B) (B) < 0 ? strlen(S) : (B)
#define utf8_tounicode(S, CP) (*(CP) = *(S), 1)
#define utf8_upper(C) toupper(C)
#define utf8_lower(C) tolower(C)
#define utf8_index(C, I) (I)
#define utf8_charlen(C) 1
#define utf8_prev_len(S, L) 1

#else
#if !defined(JIM_BOOTSTRAP)
/**
 * Returns the length of the utf-8 sequence starting with 'c'.
 *
 * Returns 1-4, or -1 if this is not a valid start byte.
 *
 * Note that charlen=4 is not supported by the rest of the API.
 */
int utf8_charlen(int c);

/**
 * Returns the number of characters in the utf-8
 * string of the given byte length.
 *
 * Any bytes which are not part of an valid utf-8
 * sequence are treated as individual characters.
 *
 * The string *must* be null terminated.
 *
 * Does not support unicode code points > \uffff
 */
int utf8_strlen(const char *str, int bytelen);

/**
 * Returns the byte index of the given character in the utf-8 string.
 *
 * The string *must* be null terminated.
 *
 * This will return the byte length of a utf-8 string
 * if given the char length.
 */
int utf8_index(const char *str, int charindex);

/**
 * Returns the unicode codepoint corresponding to the
 * utf-8 sequence 'str'.
 *
 * Stores the result in *uc and returns the number of bytes
 * consumed.
 *
 * If 'str' is null terminated, then an invalid utf-8 sequence
 * at the end of the string will be returned as individual bytes.
 *
 * If it is not null terminated, the length *must* be checked first.
 *
 * Does not support unicode code points > \uffff
 */
int utf8_tounicode(const char *str, int *uc);

/**
 * Returns the number of bytes before 'str' that the previous
 * utf-8 character sequence starts (which may be the middle of a sequence).
 *
 * Looks back at most 'len' bytes backwards, which must be > 0.
 * If no start char is found, returns -len
 */
int utf8_prev_len(const char *str, int len);

/**
 * Returns the upper-case variant of the given unicode codepoint.
 *
 * Does not support unicode code points > \uffff
 */
int utf8_upper(int uc);

/**
 * Returns the lower-case variant of the given unicode codepoint.
 *
 * NOTE: Use utf8_upper() in preference for case-insensitive matching.
 *
 * Does not support unicode code points > \uffff
 */
int utf8_lower(int uc);
#endif /* JIM_BOOTSTRAP */

#endif

#endif