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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
/*
*******************************************************************************
*
* Copyright (C) 1999-2004, International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
* file name: utf.h
* encoding: US-ASCII
* tab size: 8 (not used)
* indentation:4
*
* created on: 1999sep09
* created by: Markus W. Scherer
*/
/**
* \file
* \brief C API: Code point macros
*
* This file defines macros for checking whether a code point is
* a surrogate or a non-character etc.
*
* The UChar and UChar32 data types for Unicode code units and code points
* are defined in umachines.h because they can be machine-dependent.
*
* utf.h is included by utypes.h and itself includes utf8.h and utf16.h after some
* common definitions. Those files define macros for efficiently getting code points
* in and out of UTF-8/16 strings.
* utf16.h macros have "U16_" prefixes.
* utf8.h defines similar macros with "U8_" prefixes for UTF-8 string handling.
*
* ICU processes 16-bit Unicode strings.
* Most of the time, such strings are well-formed UTF-16.
* Single, unpaired surrogates must be handled as well, and are treated in ICU
* like regular code points where possible.
* (Pairs of surrogate code points are indistinguishable from supplementary
* code points encoded as pairs of supplementary code units.)
*
* In fact, almost all Unicode code points in normal text (>99%)
* are on the BMP (<=U+ffff) and even <=U+d7ff.
* ICU functions handle supplementary code points (U+10000..U+10ffff)
* but are optimized for the much more frequently occurring BMP code points.
*
* utf.h defines UChar to be an unsigned 16-bit integer. If this matches wchar_t, then
* UChar is defined to be exactly wchar_t, otherwise uint16_t.
*
* UChar32 is defined to be a signed 32-bit integer (int32_t), large enough for a 21-bit
* Unicode code point (Unicode scalar value, 0..0x10ffff).
* Before ICU 2.4, the definition of UChar32 was similarly platform-dependent as
* the definition of UChar. For details see the documentation for UChar32 itself.
*
* utf.h also defines a small number of C macros for single Unicode code points.
* These are simple checks for surrogates and non-characters.
* For actual Unicode character properties see uchar.h.
*
* By default, string operations must be done with error checking in case
* a string is not well-formed UTF-16.
* The macros will detect if a surrogate code unit is unpaired
* (lead unit without trail unit or vice versa) and just return the unit itself
* as the code point.
* (It is an accidental property of Unicode and UTF-16 that all
* malformed sequences can be expressed unambiguously with a distinct subrange
* of Unicode code points.)
*
* When it is safe to assume that text is well-formed UTF-16
* (does not contain single, unpaired surrogates), then one can use
* U16_..._UNSAFE macros.
* These do not check for proper code unit sequences or truncated text and may
* yield wrong results or even cause a crash if they are used with "malformed"
* text.
* In practice, U16_..._UNSAFE macros will produce slightly less code but
* should not be faster because the processing is only different when a
* surrogate code unit is detected, which will be rare.
*
* Similarly for UTF-8, there are "safe" macros without a suffix,
* and U8_..._UNSAFE versions.
* The performance differences are much larger here because UTF-8 provides so
* many opportunities for malformed sequences.
* The unsafe UTF-8 macros are entirely implemented inside the macro definitions
* and are fast, while the safe UTF-8 macros call functions for all but the
* trivial (ASCII) cases.
*
* Unlike with UTF-16, malformed sequences cannot be expressed with distinct
* code point values (0..U+10ffff). They are indicated with negative values instead.
*
* For more information see the ICU User Guide Strings chapter
* (http://oss.software.ibm.com/icu/userguide/).
*
* <em>Usage:</em>
* ICU coding guidelines for if() statements should be followed when using these macros.
* Compound statements (curly braces {}) must be used for if-else-while...
* bodies and all macro statements should be terminated with semicolon.
*
* @stable ICU 2.4
*/
#ifndef __UTF_H__
#define __UTF_H__
#include "unicode/utypes.h"
/* include the utfXX.h after the following definitions */
/* single-code point definitions -------------------------------------------- */
/**
* This value is intended for sentinel values for APIs that
* (take or) return single code points (UChar32).
* It is outside of the Unicode code point range 0..0x10ffff.
*
* For example, a "done" or "error" value in a new API
* could be indicated with U_SENTINEL.
*
* ICU APIs designed before ICU 2.4 usually define service-specific "done"
* values, mostly 0xffff.
* Those may need to be distinguished from
* actual U+ffff text contents by calling functions like
* CharacterIterator::hasNext() or UnicodeString::length().
*
* @return -1
* @see UChar32
* @stable ICU 2.4
*/
#define U_SENTINEL (-1)
/**
* Is this code point a Unicode noncharacter?
* @param c 32-bit code point
* @return TRUE or FALSE
* @stable ICU 2.4
*/
#define U_IS_UNICODE_NONCHAR(c) \
((c)>=0xfdd0 && \
((uint32_t)(c)<=0xfdef || ((c)&0xfffe)==0xfffe) && \
(uint32_t)(c)<=0x10ffff)
/**
* Is c a Unicode code point value (0..U+10ffff)
* that can be assigned a character?
*
* Code points that are not characters include:
* - single surrogate code points (U+d800..U+dfff, 2048 code points)
* - the last two code points on each plane (U+__fffe and U+__ffff, 34 code points)
* - U+fdd0..U+fdef (new with Unicode 3.1, 32 code points)
* - the highest Unicode code point value is U+10ffff
*
* This means that all code points below U+d800 are character code points,
* and that boundary is tested first for performance.
*
* @param c 32-bit code point
* @return TRUE or FALSE
* @stable ICU 2.4
*/
#define U_IS_UNICODE_CHAR(c) \
((uint32_t)(c)<0xd800 || \
((uint32_t)(c)>0xdfff && \
(uint32_t)(c)<=0x10ffff && \
!U_IS_UNICODE_NONCHAR(c)))
#ifndef U_HIDE_DRAFT_API
/**
* Is this code point a BMP code point (U+0000..U+ffff)?
* @param c 32-bit code point
* @return TRUE or FALSE
* @draft ICU 2.8
*/
#define U_IS_BMP(c) ((uint32_t)(c)<=0xffff)
/**
* Is this code point a supplementary code point (U+10000..U+10ffff)?
* @param c 32-bit code point
* @return TRUE or FALSE
* @draft ICU 2.8
*/
#define U_IS_SUPPLEMENTARY(c) ((uint32_t)((c)-0x10000)<=0xfffff)
#endif /*U_HIDE_DRAFT_API*/
/**
* Is this code point a lead surrogate (U+d800..U+dbff)?
* @param c 32-bit code point
* @return TRUE or FALSE
* @stable ICU 2.4
*/
#define U_IS_LEAD(c) (((c)&0xfffffc00)==0xd800)
/**
* Is this code point a trail surrogate (U+dc00..U+dfff)?
* @param c 32-bit code point
* @return TRUE or FALSE
* @stable ICU 2.4
*/
#define U_IS_TRAIL(c) (((c)&0xfffffc00)==0xdc00)
/**
* Is this code point a surrogate (U+d800..U+dfff)?
* @param c 32-bit code point
* @return TRUE or FALSE
* @stable ICU 2.4
*/
#define U_IS_SURROGATE(c) (((c)&0xfffff800)==0xd800)
/**
* Assuming c is a surrogate code point (U_IS_SURROGATE(c)),
* is it a lead surrogate?
* @param c 32-bit code point
* @return TRUE or FALSE
* @stable ICU 2.4
*/
#define U_IS_SURROGATE_LEAD(c) (((c)&0x400)==0)
/* include the utfXX.h ------------------------------------------------------ */
#include "unicode/utf8.h"
#include "unicode/utf16.h"
/* utf_old.h contains deprecated, pre-ICU 2.4 definitions */
#include "unicode/utf_old.h"
#endif
|
