OLD | NEW |
| (Empty) |
1 /* | |
2 ******************************************************************************* | |
3 * | |
4 * Copyright (C) 1999-2009, International Business Machines | |
5 * Corporation and others. All Rights Reserved. | |
6 * | |
7 ******************************************************************************* | |
8 * file name: utf8.h | |
9 * encoding: US-ASCII | |
10 * tab size: 8 (not used) | |
11 * indentation:4 | |
12 * | |
13 * created on: 1999sep13 | |
14 * created by: Markus W. Scherer | |
15 */ | |
16 | |
17 /** | |
18 * \file | |
19 * \brief C API: 8-bit Unicode handling macros | |
20 * | |
21 * This file defines macros to deal with 8-bit Unicode (UTF-8) code units (bytes
) and strings. | |
22 * utf8.h is included by utf.h after unicode/umachine.h | |
23 * and some common definitions. | |
24 * | |
25 * For more information see utf.h and the ICU User Guide Strings chapter | |
26 * (http://icu-project.org/userguide/strings.html). | |
27 * | |
28 * <em>Usage:</em> | |
29 * ICU coding guidelines for if() statements should be followed when using these
macros. | |
30 * Compound statements (curly braces {}) must be used for if-else-while... | |
31 * bodies and all macro statements should be terminated with semicolon. | |
32 */ | |
33 | |
34 #ifndef __UTF8_H__ | |
35 #define __UTF8_H__ | |
36 | |
37 /* utf.h must be included first. */ | |
38 #ifndef __UTF_H__ | |
39 # include "unicode/utf.h" | |
40 #endif | |
41 | |
42 /* internal definitions ----------------------------------------------------- */ | |
43 | |
44 /** | |
45 * \var utf8_countTrailBytes | |
46 * Internal array with numbers of trail bytes for any given byte used in | |
47 * lead byte position. | |
48 * | |
49 * This is internal since it is not meant to be called directly by external clie
nts; | |
50 * however it is called by public macros in this file and thus must remain stabl
e, | |
51 * and should not be hidden when other internal functions are hidden (otherwise | |
52 * public macros would fail to compile). | |
53 * @internal | |
54 */ | |
55 #ifdef U_UTF8_IMPL | |
56 U_EXPORT const uint8_t | |
57 #elif defined(U_STATIC_IMPLEMENTATION) || defined(U_COMMON_IMPLEMENTATION) | |
58 U_CFUNC const uint8_t | |
59 #else | |
60 U_CFUNC U_IMPORT const uint8_t /* U_IMPORT2? */ /*U_IMPORT*/ | |
61 #endif | |
62 utf8_countTrailBytes[256]; | |
63 | |
64 /** | |
65 * Count the trail bytes for a UTF-8 lead byte. | |
66 * | |
67 * This is internal since it is not meant to be called directly by external clie
nts; | |
68 * however it is called by public macros in this file and thus must remain stabl
e. | |
69 * @internal | |
70 */ | |
71 #define U8_COUNT_TRAIL_BYTES(leadByte) (utf8_countTrailBytes[(uint8_t)leadByte]) | |
72 | |
73 /** | |
74 * Mask a UTF-8 lead byte, leave only the lower bits that form part of the code
point value. | |
75 * | |
76 * This is internal since it is not meant to be called directly by external clie
nts; | |
77 * however it is called by public macros in this file and thus must remain stabl
e. | |
78 * @internal | |
79 */ | |
80 #define U8_MASK_LEAD_BYTE(leadByte, countTrailBytes) ((leadByte)&=(1<<(6-(countT
railBytes)))-1) | |
81 | |
82 /** | |
83 * Function for handling "next code point" with error-checking. | |
84 * | |
85 * This is internal since it is not meant to be called directly by external clie
nts; | |
86 * however it is U_STABLE (not U_INTERNAL) since it is called by public macros i
n this | |
87 * file and thus must remain stable, and should not be hidden when other interna
l | |
88 * functions are hidden (otherwise public macros would fail to compile). | |
89 * @internal | |
90 */ | |
91 U_STABLE UChar32 U_EXPORT2 | |
92 utf8_nextCharSafeBody(const uint8_t *s, int32_t *pi, int32_t length, UChar32 c,
UBool strict); | |
93 | |
94 /** | |
95 * Function for handling "append code point" with error-checking. | |
96 * | |
97 * This is internal since it is not meant to be called directly by external clie
nts; | |
98 * however it is U_STABLE (not U_INTERNAL) since it is called by public macros i
n this | |
99 * file and thus must remain stable, and should not be hidden when other interna
l | |
100 * functions are hidden (otherwise public macros would fail to compile). | |
101 * @internal | |
102 */ | |
103 U_STABLE int32_t U_EXPORT2 | |
104 utf8_appendCharSafeBody(uint8_t *s, int32_t i, int32_t length, UChar32 c, UBool
*pIsError); | |
105 | |
106 /** | |
107 * Function for handling "previous code point" with error-checking. | |
108 * | |
109 * This is internal since it is not meant to be called directly by external clie
nts; | |
110 * however it is U_STABLE (not U_INTERNAL) since it is called by public macros i
n this | |
111 * file and thus must remain stable, and should not be hidden when other interna
l | |
112 * functions are hidden (otherwise public macros would fail to compile). | |
113 * @internal | |
114 */ | |
115 U_STABLE UChar32 U_EXPORT2 | |
116 utf8_prevCharSafeBody(const uint8_t *s, int32_t start, int32_t *pi, UChar32 c, U
Bool strict); | |
117 | |
118 /** | |
119 * Function for handling "skip backward one code point" with error-checking. | |
120 * | |
121 * This is internal since it is not meant to be called directly by external clie
nts; | |
122 * however it is U_STABLE (not U_INTERNAL) since it is called by public macros i
n this | |
123 * file and thus must remain stable, and should not be hidden when other interna
l | |
124 * functions are hidden (otherwise public macros would fail to compile). | |
125 * @internal | |
126 */ | |
127 U_STABLE int32_t U_EXPORT2 | |
128 utf8_back1SafeBody(const uint8_t *s, int32_t start, int32_t i); | |
129 | |
130 /* single-code point definitions -------------------------------------------- */ | |
131 | |
132 /** | |
133 * Does this code unit (byte) encode a code point by itself (US-ASCII 0..0x7f)? | |
134 * @param c 8-bit code unit (byte) | |
135 * @return TRUE or FALSE | |
136 * @stable ICU 2.4 | |
137 */ | |
138 #define U8_IS_SINGLE(c) (((c)&0x80)==0) | |
139 | |
140 /** | |
141 * Is this code unit (byte) a UTF-8 lead byte? | |
142 * @param c 8-bit code unit (byte) | |
143 * @return TRUE or FALSE | |
144 * @stable ICU 2.4 | |
145 */ | |
146 #define U8_IS_LEAD(c) ((uint8_t)((c)-0xc0)<0x3e) | |
147 | |
148 /** | |
149 * Is this code unit (byte) a UTF-8 trail byte? | |
150 * @param c 8-bit code unit (byte) | |
151 * @return TRUE or FALSE | |
152 * @stable ICU 2.4 | |
153 */ | |
154 #define U8_IS_TRAIL(c) (((c)&0xc0)==0x80) | |
155 | |
156 /** | |
157 * How many code units (bytes) are used for the UTF-8 encoding | |
158 * of this Unicode code point? | |
159 * @param c 32-bit code point | |
160 * @return 1..4, or 0 if c is a surrogate or not a Unicode code point | |
161 * @stable ICU 2.4 | |
162 */ | |
163 #define U8_LENGTH(c) \ | |
164 ((uint32_t)(c)<=0x7f ? 1 : \ | |
165 ((uint32_t)(c)<=0x7ff ? 2 : \ | |
166 ((uint32_t)(c)<=0xd7ff ? 3 : \ | |
167 ((uint32_t)(c)<=0xdfff || (uint32_t)(c)>0x10ffff ? 0 : \ | |
168 ((uint32_t)(c)<=0xffff ? 3 : 4)\ | |
169 ) \ | |
170 ) \ | |
171 ) \ | |
172 ) | |
173 | |
174 /** | |
175 * The maximum number of UTF-8 code units (bytes) per Unicode code point (U+0000
..U+10ffff). | |
176 * @return 4 | |
177 * @stable ICU 2.4 | |
178 */ | |
179 #define U8_MAX_LENGTH 4 | |
180 | |
181 /** | |
182 * Get a code point from a string at a random-access offset, | |
183 * without changing the offset. | |
184 * The offset may point to either the lead byte or one of the trail bytes | |
185 * for a code point, in which case the macro will read all of the bytes | |
186 * for the code point. | |
187 * The result is undefined if the offset points to an illegal UTF-8 | |
188 * byte sequence. | |
189 * Iteration through a string is more efficient with U8_NEXT_UNSAFE or U8_NEXT. | |
190 * | |
191 * @param s const uint8_t * string | |
192 * @param i string offset | |
193 * @param c output UChar32 variable | |
194 * @see U8_GET | |
195 * @stable ICU 2.4 | |
196 */ | |
197 #define U8_GET_UNSAFE(s, i, c) { \ | |
198 int32_t _u8_get_unsafe_index=(int32_t)(i); \ | |
199 U8_SET_CP_START_UNSAFE(s, _u8_get_unsafe_index); \ | |
200 U8_NEXT_UNSAFE(s, _u8_get_unsafe_index, c); \ | |
201 } | |
202 | |
203 /** | |
204 * Get a code point from a string at a random-access offset, | |
205 * without changing the offset. | |
206 * The offset may point to either the lead byte or one of the trail bytes | |
207 * for a code point, in which case the macro will read all of the bytes | |
208 * for the code point. | |
209 * If the offset points to an illegal UTF-8 byte sequence, then | |
210 * c is set to a negative value. | |
211 * Iteration through a string is more efficient with U8_NEXT_UNSAFE or U8_NEXT. | |
212 * | |
213 * @param s const uint8_t * string | |
214 * @param start starting string offset | |
215 * @param i string offset, must be start<=i<length | |
216 * @param length string length | |
217 * @param c output UChar32 variable, set to <0 in case of an error | |
218 * @see U8_GET_UNSAFE | |
219 * @stable ICU 2.4 | |
220 */ | |
221 #define U8_GET(s, start, i, length, c) { \ | |
222 int32_t _u8_get_index=(int32_t)(i); \ | |
223 U8_SET_CP_START(s, start, _u8_get_index); \ | |
224 U8_NEXT(s, _u8_get_index, length, c); \ | |
225 } | |
226 | |
227 /* definitions with forward iteration --------------------------------------- */ | |
228 | |
229 /** | |
230 * Get a code point from a string at a code point boundary offset, | |
231 * and advance the offset to the next code point boundary. | |
232 * (Post-incrementing forward iteration.) | |
233 * "Unsafe" macro, assumes well-formed UTF-8. | |
234 * | |
235 * The offset may point to the lead byte of a multi-byte sequence, | |
236 * in which case the macro will read the whole sequence. | |
237 * The result is undefined if the offset points to a trail byte | |
238 * or an illegal UTF-8 sequence. | |
239 * | |
240 * @param s const uint8_t * string | |
241 * @param i string offset | |
242 * @param c output UChar32 variable | |
243 * @see U8_NEXT | |
244 * @stable ICU 2.4 | |
245 */ | |
246 #define U8_NEXT_UNSAFE(s, i, c) { \ | |
247 (c)=(uint8_t)(s)[(i)++]; \ | |
248 if((uint8_t)((c)-0xc0)<0x35) { \ | |
249 uint8_t __count=U8_COUNT_TRAIL_BYTES(c); \ | |
250 U8_MASK_LEAD_BYTE(c, __count); \ | |
251 switch(__count) { \ | |
252 /* each following branch falls through to the next one */ \ | |
253 case 3: \ | |
254 (c)=((c)<<6)|((s)[(i)++]&0x3f); \ | |
255 case 2: \ | |
256 (c)=((c)<<6)|((s)[(i)++]&0x3f); \ | |
257 case 1: \ | |
258 (c)=((c)<<6)|((s)[(i)++]&0x3f); \ | |
259 /* no other branches to optimize switch() */ \ | |
260 break; \ | |
261 } \ | |
262 } \ | |
263 } | |
264 | |
265 /** | |
266 * Get a code point from a string at a code point boundary offset, | |
267 * and advance the offset to the next code point boundary. | |
268 * (Post-incrementing forward iteration.) | |
269 * "Safe" macro, checks for illegal sequences and for string boundaries. | |
270 * | |
271 * The offset may point to the lead byte of a multi-byte sequence, | |
272 * in which case the macro will read the whole sequence. | |
273 * If the offset points to a trail byte or an illegal UTF-8 sequence, then | |
274 * c is set to a negative value. | |
275 * | |
276 * @param s const uint8_t * string | |
277 * @param i string offset, must be i<length | |
278 * @param length string length | |
279 * @param c output UChar32 variable, set to <0 in case of an error | |
280 * @see U8_NEXT_UNSAFE | |
281 * @stable ICU 2.4 | |
282 */ | |
283 #define U8_NEXT(s, i, length, c) { \ | |
284 (c)=(uint8_t)(s)[(i)++]; \ | |
285 if((c)>=0x80) { \ | |
286 uint8_t __t1, __t2; \ | |
287 if( /* handle U+1000..U+CFFF inline */ \ | |
288 (0xe0<(c) && (c)<=0xec) && \ | |
289 (((i)+1)<(length)) && \ | |
290 (__t1=(uint8_t)((s)[i]-0x80))<=0x3f && \ | |
291 (__t2=(uint8_t)((s)[(i)+1]-0x80))<= 0x3f \ | |
292 ) { \ | |
293 /* no need for (c&0xf) because the upper bits are truncated after <<
12 in the cast to (UChar) */ \ | |
294 (c)=(UChar)(((c)<<12)|(__t1<<6)|__t2); \ | |
295 (i)+=2; \ | |
296 } else if( /* handle U+0080..U+07FF inline */ \ | |
297 ((c)<0xe0 && (c)>=0xc2) && \ | |
298 ((i)<(length)) && \ | |
299 (__t1=(uint8_t)((s)[i]-0x80))<=0x3f \ | |
300 ) { \ | |
301 (c)=(UChar)((((c)&0x1f)<<6)|__t1); \ | |
302 ++(i); \ | |
303 } else if(U8_IS_LEAD(c)) { \ | |
304 /* function call for "complicated" and error cases */ \ | |
305 (c)=utf8_nextCharSafeBody((const uint8_t *)s, &(i), (int32_t)(length
), c, -1); \ | |
306 } else { \ | |
307 (c)=U_SENTINEL; \ | |
308 } \ | |
309 } \ | |
310 } | |
311 | |
312 /** | |
313 * Append a code point to a string, overwriting 1 to 4 bytes. | |
314 * The offset points to the current end of the string contents | |
315 * and is advanced (post-increment). | |
316 * "Unsafe" macro, assumes a valid code point and sufficient space in the string
. | |
317 * Otherwise, the result is undefined. | |
318 * | |
319 * @param s const uint8_t * string buffer | |
320 * @param i string offset | |
321 * @param c code point to append | |
322 * @see U8_APPEND | |
323 * @stable ICU 2.4 | |
324 */ | |
325 #define U8_APPEND_UNSAFE(s, i, c) { \ | |
326 if((uint32_t)(c)<=0x7f) { \ | |
327 (s)[(i)++]=(uint8_t)(c); \ | |
328 } else { \ | |
329 if((uint32_t)(c)<=0x7ff) { \ | |
330 (s)[(i)++]=(uint8_t)(((c)>>6)|0xc0); \ | |
331 } else { \ | |
332 if((uint32_t)(c)<=0xffff) { \ | |
333 (s)[(i)++]=(uint8_t)(((c)>>12)|0xe0); \ | |
334 } else { \ | |
335 (s)[(i)++]=(uint8_t)(((c)>>18)|0xf0); \ | |
336 (s)[(i)++]=(uint8_t)((((c)>>12)&0x3f)|0x80); \ | |
337 } \ | |
338 (s)[(i)++]=(uint8_t)((((c)>>6)&0x3f)|0x80); \ | |
339 } \ | |
340 (s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80); \ | |
341 } \ | |
342 } | |
343 | |
344 /** | |
345 * Append a code point to a string, overwriting 1 to 4 bytes. | |
346 * The offset points to the current end of the string contents | |
347 * and is advanced (post-increment). | |
348 * "Safe" macro, checks for a valid code point. | |
349 * If a non-ASCII code point is written, checks for sufficient space in the stri
ng. | |
350 * If the code point is not valid or trail bytes do not fit, | |
351 * then isError is set to TRUE. | |
352 * | |
353 * @param s const uint8_t * string buffer | |
354 * @param i string offset, must be i<capacity | |
355 * @param capacity size of the string buffer | |
356 * @param c code point to append | |
357 * @param isError output UBool set to TRUE if an error occurs, otherwise not mod
ified | |
358 * @see U8_APPEND_UNSAFE | |
359 * @stable ICU 2.4 | |
360 */ | |
361 #define U8_APPEND(s, i, capacity, c, isError) { \ | |
362 if((uint32_t)(c)<=0x7f) { \ | |
363 (s)[(i)++]=(uint8_t)(c); \ | |
364 } else if((uint32_t)(c)<=0x7ff && (i)+1<(capacity)) { \ | |
365 (s)[(i)++]=(uint8_t)(((c)>>6)|0xc0); \ | |
366 (s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80); \ | |
367 } else if((uint32_t)(c)<=0xd7ff && (i)+2<(capacity)) { \ | |
368 (s)[(i)++]=(uint8_t)(((c)>>12)|0xe0); \ | |
369 (s)[(i)++]=(uint8_t)((((c)>>6)&0x3f)|0x80); \ | |
370 (s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80); \ | |
371 } else { \ | |
372 (i)=utf8_appendCharSafeBody(s, (int32_t)(i), (int32_t)(capacity), c, &(i
sError)); \ | |
373 } \ | |
374 } | |
375 | |
376 /** | |
377 * Advance the string offset from one code point boundary to the next. | |
378 * (Post-incrementing iteration.) | |
379 * "Unsafe" macro, assumes well-formed UTF-8. | |
380 * | |
381 * @param s const uint8_t * string | |
382 * @param i string offset | |
383 * @see U8_FWD_1 | |
384 * @stable ICU 2.4 | |
385 */ | |
386 #define U8_FWD_1_UNSAFE(s, i) { \ | |
387 (i)+=1+U8_COUNT_TRAIL_BYTES((s)[i]); \ | |
388 } | |
389 | |
390 /** | |
391 * Advance the string offset from one code point boundary to the next. | |
392 * (Post-incrementing iteration.) | |
393 * "Safe" macro, checks for illegal sequences and for string boundaries. | |
394 * | |
395 * @param s const uint8_t * string | |
396 * @param i string offset, must be i<length | |
397 * @param length string length | |
398 * @see U8_FWD_1_UNSAFE | |
399 * @stable ICU 2.4 | |
400 */ | |
401 #define U8_FWD_1(s, i, length) { \ | |
402 uint8_t __b=(uint8_t)(s)[(i)++]; \ | |
403 if(U8_IS_LEAD(__b)) { \ | |
404 uint8_t __count=U8_COUNT_TRAIL_BYTES(__b); \ | |
405 if((i)+__count>(length)) { \ | |
406 __count=(uint8_t)((length)-(i)); \ | |
407 } \ | |
408 while(__count>0 && U8_IS_TRAIL((s)[i])) { \ | |
409 ++(i); \ | |
410 --__count; \ | |
411 } \ | |
412 } \ | |
413 } | |
414 | |
415 /** | |
416 * Advance the string offset from one code point boundary to the n-th next one, | |
417 * i.e., move forward by n code points. | |
418 * (Post-incrementing iteration.) | |
419 * "Unsafe" macro, assumes well-formed UTF-8. | |
420 * | |
421 * @param s const uint8_t * string | |
422 * @param i string offset | |
423 * @param n number of code points to skip | |
424 * @see U8_FWD_N | |
425 * @stable ICU 2.4 | |
426 */ | |
427 #define U8_FWD_N_UNSAFE(s, i, n) { \ | |
428 int32_t __N=(n); \ | |
429 while(__N>0) { \ | |
430 U8_FWD_1_UNSAFE(s, i); \ | |
431 --__N; \ | |
432 } \ | |
433 } | |
434 | |
435 /** | |
436 * Advance the string offset from one code point boundary to the n-th next one, | |
437 * i.e., move forward by n code points. | |
438 * (Post-incrementing iteration.) | |
439 * "Safe" macro, checks for illegal sequences and for string boundaries. | |
440 * | |
441 * @param s const uint8_t * string | |
442 * @param i string offset, must be i<length | |
443 * @param length string length | |
444 * @param n number of code points to skip | |
445 * @see U8_FWD_N_UNSAFE | |
446 * @stable ICU 2.4 | |
447 */ | |
448 #define U8_FWD_N(s, i, length, n) { \ | |
449 int32_t __N=(n); \ | |
450 while(__N>0 && (i)<(length)) { \ | |
451 U8_FWD_1(s, i, length); \ | |
452 --__N; \ | |
453 } \ | |
454 } | |
455 | |
456 /** | |
457 * Adjust a random-access offset to a code point boundary | |
458 * at the start of a code point. | |
459 * If the offset points to a UTF-8 trail byte, | |
460 * then the offset is moved backward to the corresponding lead byte. | |
461 * Otherwise, it is not modified. | |
462 * "Unsafe" macro, assumes well-formed UTF-8. | |
463 * | |
464 * @param s const uint8_t * string | |
465 * @param i string offset | |
466 * @see U8_SET_CP_START | |
467 * @stable ICU 2.4 | |
468 */ | |
469 #define U8_SET_CP_START_UNSAFE(s, i) { \ | |
470 while(U8_IS_TRAIL((s)[i])) { --(i); } \ | |
471 } | |
472 | |
473 /** | |
474 * Adjust a random-access offset to a code point boundary | |
475 * at the start of a code point. | |
476 * If the offset points to a UTF-8 trail byte, | |
477 * then the offset is moved backward to the corresponding lead byte. | |
478 * Otherwise, it is not modified. | |
479 * "Safe" macro, checks for illegal sequences and for string boundaries. | |
480 * | |
481 * @param s const uint8_t * string | |
482 * @param start starting string offset (usually 0) | |
483 * @param i string offset, must be start<=i | |
484 * @see U8_SET_CP_START_UNSAFE | |
485 * @stable ICU 2.4 | |
486 */ | |
487 #define U8_SET_CP_START(s, start, i) { \ | |
488 if(U8_IS_TRAIL((s)[(i)])) { \ | |
489 (i)=utf8_back1SafeBody(s, start, (int32_t)(i)); \ | |
490 } \ | |
491 } | |
492 | |
493 /* definitions with backward iteration -------------------------------------- */ | |
494 | |
495 /** | |
496 * Move the string offset from one code point boundary to the previous one | |
497 * and get the code point between them. | |
498 * (Pre-decrementing backward iteration.) | |
499 * "Unsafe" macro, assumes well-formed UTF-8. | |
500 * | |
501 * The input offset may be the same as the string length. | |
502 * If the offset is behind a multi-byte sequence, then the macro will read | |
503 * the whole sequence. | |
504 * If the offset is behind a lead byte, then that itself | |
505 * will be returned as the code point. | |
506 * The result is undefined if the offset is behind an illegal UTF-8 sequence. | |
507 * | |
508 * @param s const uint8_t * string | |
509 * @param i string offset | |
510 * @param c output UChar32 variable | |
511 * @see U8_PREV | |
512 * @stable ICU 2.4 | |
513 */ | |
514 #define U8_PREV_UNSAFE(s, i, c) { \ | |
515 (c)=(uint8_t)(s)[--(i)]; \ | |
516 if(U8_IS_TRAIL(c)) { \ | |
517 uint8_t __b, __count=1, __shift=6; \ | |
518 \ | |
519 /* c is a trail byte */ \ | |
520 (c)&=0x3f; \ | |
521 for(;;) { \ | |
522 __b=(uint8_t)(s)[--(i)]; \ | |
523 if(__b>=0xc0) { \ | |
524 U8_MASK_LEAD_BYTE(__b, __count); \ | |
525 (c)|=(UChar32)__b<<__shift; \ | |
526 break; \ | |
527 } else { \ | |
528 (c)|=(UChar32)(__b&0x3f)<<__shift; \ | |
529 ++__count; \ | |
530 __shift+=6; \ | |
531 } \ | |
532 } \ | |
533 } \ | |
534 } | |
535 | |
536 /** | |
537 * Move the string offset from one code point boundary to the previous one | |
538 * and get the code point between them. | |
539 * (Pre-decrementing backward iteration.) | |
540 * "Safe" macro, checks for illegal sequences and for string boundaries. | |
541 * | |
542 * The input offset may be the same as the string length. | |
543 * If the offset is behind a multi-byte sequence, then the macro will read | |
544 * the whole sequence. | |
545 * If the offset is behind a lead byte, then that itself | |
546 * will be returned as the code point. | |
547 * If the offset is behind an illegal UTF-8 sequence, then c is set to a negativ
e value. | |
548 * | |
549 * @param s const uint8_t * string | |
550 * @param start starting string offset (usually 0) | |
551 * @param i string offset, must be start<i | |
552 * @param c output UChar32 variable, set to <0 in case of an error | |
553 * @see U8_PREV_UNSAFE | |
554 * @stable ICU 2.4 | |
555 */ | |
556 #define U8_PREV(s, start, i, c) { \ | |
557 (c)=(uint8_t)(s)[--(i)]; \ | |
558 if((c)>=0x80) { \ | |
559 if((c)<=0xbf) { \ | |
560 (c)=utf8_prevCharSafeBody((const uint8_t *)s, start, &(i), c, -1); \ | |
561 } else { \ | |
562 (c)=U_SENTINEL; \ | |
563 } \ | |
564 } \ | |
565 } | |
566 | |
567 /** | |
568 * Move the string offset from one code point boundary to the previous one. | |
569 * (Pre-decrementing backward iteration.) | |
570 * The input offset may be the same as the string length. | |
571 * "Unsafe" macro, assumes well-formed UTF-8. | |
572 * | |
573 * @param s const uint8_t * string | |
574 * @param i string offset | |
575 * @see U8_BACK_1 | |
576 * @stable ICU 2.4 | |
577 */ | |
578 #define U8_BACK_1_UNSAFE(s, i) { \ | |
579 while(U8_IS_TRAIL((s)[--(i)])) {} \ | |
580 } | |
581 | |
582 /** | |
583 * Move the string offset from one code point boundary to the previous one. | |
584 * (Pre-decrementing backward iteration.) | |
585 * The input offset may be the same as the string length. | |
586 * "Safe" macro, checks for illegal sequences and for string boundaries. | |
587 * | |
588 * @param s const uint8_t * string | |
589 * @param start starting string offset (usually 0) | |
590 * @param i string offset, must be start<i | |
591 * @see U8_BACK_1_UNSAFE | |
592 * @stable ICU 2.4 | |
593 */ | |
594 #define U8_BACK_1(s, start, i) { \ | |
595 if(U8_IS_TRAIL((s)[--(i)])) { \ | |
596 (i)=utf8_back1SafeBody(s, start, (int32_t)(i)); \ | |
597 } \ | |
598 } | |
599 | |
600 /** | |
601 * Move the string offset from one code point boundary to the n-th one before it
, | |
602 * i.e., move backward by n code points. | |
603 * (Pre-decrementing backward iteration.) | |
604 * The input offset may be the same as the string length. | |
605 * "Unsafe" macro, assumes well-formed UTF-8. | |
606 * | |
607 * @param s const uint8_t * string | |
608 * @param i string offset | |
609 * @param n number of code points to skip | |
610 * @see U8_BACK_N | |
611 * @stable ICU 2.4 | |
612 */ | |
613 #define U8_BACK_N_UNSAFE(s, i, n) { \ | |
614 int32_t __N=(n); \ | |
615 while(__N>0) { \ | |
616 U8_BACK_1_UNSAFE(s, i); \ | |
617 --__N; \ | |
618 } \ | |
619 } | |
620 | |
621 /** | |
622 * Move the string offset from one code point boundary to the n-th one before it
, | |
623 * i.e., move backward by n code points. | |
624 * (Pre-decrementing backward iteration.) | |
625 * The input offset may be the same as the string length. | |
626 * "Safe" macro, checks for illegal sequences and for string boundaries. | |
627 * | |
628 * @param s const uint8_t * string | |
629 * @param start index of the start of the string | |
630 * @param i string offset, must be start<i | |
631 * @param n number of code points to skip | |
632 * @see U8_BACK_N_UNSAFE | |
633 * @stable ICU 2.4 | |
634 */ | |
635 #define U8_BACK_N(s, start, i, n) { \ | |
636 int32_t __N=(n); \ | |
637 while(__N>0 && (i)>(start)) { \ | |
638 U8_BACK_1(s, start, i); \ | |
639 --__N; \ | |
640 } \ | |
641 } | |
642 | |
643 /** | |
644 * Adjust a random-access offset to a code point boundary after a code point. | |
645 * If the offset is behind a partial multi-byte sequence, | |
646 * then the offset is incremented to behind the whole sequence. | |
647 * Otherwise, it is not modified. | |
648 * The input offset may be the same as the string length. | |
649 * "Unsafe" macro, assumes well-formed UTF-8. | |
650 * | |
651 * @param s const uint8_t * string | |
652 * @param i string offset | |
653 * @see U8_SET_CP_LIMIT | |
654 * @stable ICU 2.4 | |
655 */ | |
656 #define U8_SET_CP_LIMIT_UNSAFE(s, i) { \ | |
657 U8_BACK_1_UNSAFE(s, i); \ | |
658 U8_FWD_1_UNSAFE(s, i); \ | |
659 } | |
660 | |
661 /** | |
662 * Adjust a random-access offset to a code point boundary after a code point. | |
663 * If the offset is behind a partial multi-byte sequence, | |
664 * then the offset is incremented to behind the whole sequence. | |
665 * Otherwise, it is not modified. | |
666 * The input offset may be the same as the string length. | |
667 * "Safe" macro, checks for illegal sequences and for string boundaries. | |
668 * | |
669 * @param s const uint8_t * string | |
670 * @param start starting string offset (usually 0) | |
671 * @param i string offset, must be start<=i<=length | |
672 * @param length string length | |
673 * @see U8_SET_CP_LIMIT_UNSAFE | |
674 * @stable ICU 2.4 | |
675 */ | |
676 #define U8_SET_CP_LIMIT(s, start, i, length) { \ | |
677 if((start)<(i) && (i)<(length)) { \ | |
678 U8_BACK_1(s, start, i); \ | |
679 U8_FWD_1(s, i, length); \ | |
680 } \ | |
681 } | |
682 | |
683 #endif | |
OLD | NEW |