Commit | Line | Data |
---|---|---|
b7b65b15 | 1 | /* Low-level bidirectional buffer-scanning functions for GNU Emacs. |
73b0cd50 | 2 | Copyright (C) 2000-2001, 2004-2005, 2009-2011 |
b118e65f | 3 | Free Software Foundation, Inc. |
b7b65b15 EZ |
4 | |
5 | This file is part of GNU Emacs. | |
6 | ||
a8d11bd3 | 7 | GNU Emacs is free software: you can redistribute it and/or modify |
b7b65b15 | 8 | it under the terms of the GNU General Public License as published by |
a8d11bd3 EZ |
9 | the Free Software Foundation, either version 3 of the License, or |
10 | (at your option) any later version. | |
b7b65b15 EZ |
11 | |
12 | GNU Emacs is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
b7b65b15 | 17 | You should have received a copy of the GNU General Public License |
a8d11bd3 | 18 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
b7b65b15 | 19 | |
2d6e4628 EZ |
20 | /* Written by Eli Zaretskii <eliz@gnu.org>. |
21 | ||
22 | A sequential implementation of the Unicode Bidirectional algorithm, | |
b7b65b15 EZ |
23 | as per UAX#9, a part of the Unicode Standard. |
24 | ||
25 | Unlike the reference and most other implementations, this one is | |
940afb59 EZ |
26 | designed to be called once for every character in the buffer or |
27 | string. | |
b7b65b15 | 28 | |
4b292a22 | 29 | The main entry point is bidi_move_to_visually_next. Each time it |
b7b65b15 EZ |
30 | is called, it finds the next character in the visual order, and |
31 | returns its information in a special structure. The caller is then | |
32 | expected to process this character for display or any other | |
4b292a22 EZ |
33 | purposes, and call bidi_move_to_visually_next for the next |
34 | character. See the comments in bidi_move_to_visually_next for more | |
35 | details about its algorithm that finds the next visual-order | |
b7b65b15 EZ |
36 | character by resolving their levels on the fly. |
37 | ||
940afb59 EZ |
38 | The two other entry points are bidi_paragraph_init and |
39 | bidi_mirror_char. The first determines the base direction of a | |
40 | paragraph, while the second returns the mirrored version of its | |
41 | argument character. | |
42 | ||
89d3374a EZ |
43 | If you want to understand the code, you will have to read it |
44 | together with the relevant portions of UAX#9. The comments include | |
45 | references to UAX#9 rules, for that very reason. | |
46 | ||
b7b65b15 EZ |
47 | A note about references to UAX#9 rules: if the reference says |
48 | something like "X9/Retaining", it means that you need to refer to | |
49 | rule X9 and to its modifications decribed in the "Implementation | |
50 | Notes" section of UAX#9, under "Retaining Format Codes". */ | |
51 | ||
b7b65b15 | 52 | #include <config.h> |
b7b65b15 | 53 | #include <stdio.h> |
29e3d8d1 EZ |
54 | #include <setjmp.h> |
55 | ||
b7b65b15 EZ |
56 | #include "lisp.h" |
57 | #include "buffer.h" | |
58 | #include "character.h" | |
59 | #include "dispextern.h" | |
60 | ||
61 | static int bidi_initialized = 0; | |
62 | ||
cbc4fd20 | 63 | static Lisp_Object bidi_type_table, bidi_mirror_table; |
b7b65b15 EZ |
64 | |
65 | #define LRM_CHAR 0x200E | |
66 | #define RLM_CHAR 0x200F | |
b7b65b15 | 67 | #define BIDI_EOB -1 |
b7b65b15 | 68 | |
b7b65b15 EZ |
69 | /* Local data structures. (Look in dispextern.h for the rest.) */ |
70 | ||
71 | /* What we need to know about the current paragraph. */ | |
72 | struct bidi_paragraph_info { | |
61bfec98 EZ |
73 | EMACS_INT start_bytepos; /* byte position where it begins */ |
74 | EMACS_INT end_bytepos; /* byte position where it ends */ | |
75 | int embedding_level; /* its basic embedding level */ | |
76 | bidi_dir_t base_dir; /* its base direction */ | |
b7b65b15 EZ |
77 | }; |
78 | ||
79 | /* Data type for describing the bidirectional character categories. */ | |
80 | typedef enum { | |
81 | UNKNOWN_BC, | |
82 | NEUTRAL, | |
83 | WEAK, | |
84 | STRONG | |
85 | } bidi_category_t; | |
86 | ||
e78aecca | 87 | extern int bidi_ignore_explicit_marks_for_paragraph_level EXTERNALLY_VISIBLE; |
b7b65b15 EZ |
88 | int bidi_ignore_explicit_marks_for_paragraph_level = 1; |
89 | ||
372b7a95 | 90 | static Lisp_Object paragraph_start_re, paragraph_separate_re; |
6bff6497 | 91 | static Lisp_Object Qparagraph_start, Qparagraph_separate; |
b7b65b15 | 92 | |
b7b65b15 | 93 | static void |
971de7fb | 94 | bidi_initialize (void) |
b7b65b15 | 95 | { |
317fbf33 EZ |
96 | |
97 | #include "biditype.h" | |
cbc4fd20 | 98 | #include "bidimirror.h" |
317fbf33 | 99 | |
b7b65b15 EZ |
100 | int i; |
101 | ||
102 | bidi_type_table = Fmake_char_table (Qnil, make_number (STRONG_L)); | |
2d6e4628 | 103 | staticpro (&bidi_type_table); |
b7b65b15 EZ |
104 | |
105 | for (i = 0; i < sizeof bidi_type / sizeof bidi_type[0]; i++) | |
317fbf33 | 106 | char_table_set_range (bidi_type_table, bidi_type[i].from, bidi_type[i].to, |
b7b65b15 | 107 | make_number (bidi_type[i].type)); |
6bff6497 | 108 | |
cbc4fd20 EZ |
109 | bidi_mirror_table = Fmake_char_table (Qnil, Qnil); |
110 | staticpro (&bidi_mirror_table); | |
111 | ||
112 | for (i = 0; i < sizeof bidi_mirror / sizeof bidi_mirror[0]; i++) | |
113 | char_table_set (bidi_mirror_table, bidi_mirror[i].from, | |
114 | make_number (bidi_mirror[i].to)); | |
115 | ||
b4bf28b7 SM |
116 | Qparagraph_start = intern ("paragraph-start"); |
117 | staticpro (&Qparagraph_start); | |
372b7a95 EZ |
118 | paragraph_start_re = Fsymbol_value (Qparagraph_start); |
119 | if (!STRINGP (paragraph_start_re)) | |
120 | paragraph_start_re = build_string ("\f\\|[ \t]*$"); | |
121 | staticpro (¶graph_start_re); | |
b4bf28b7 SM |
122 | Qparagraph_separate = intern ("paragraph-separate"); |
123 | staticpro (&Qparagraph_separate); | |
372b7a95 EZ |
124 | paragraph_separate_re = Fsymbol_value (Qparagraph_separate); |
125 | if (!STRINGP (paragraph_separate_re)) | |
126 | paragraph_separate_re = build_string ("[ \t\f]*$"); | |
127 | staticpro (¶graph_separate_re); | |
b7b65b15 EZ |
128 | bidi_initialized = 1; |
129 | } | |
130 | ||
6bff6497 EZ |
131 | /* Return the bidi type of a character CH, subject to the current |
132 | directional OVERRIDE. */ | |
fd3998ff | 133 | static INLINE bidi_type_t |
6bff6497 | 134 | bidi_get_type (int ch, bidi_dir_t override) |
b7b65b15 | 135 | { |
6bff6497 EZ |
136 | bidi_type_t default_type; |
137 | ||
e7402cb2 EZ |
138 | if (ch == BIDI_EOB) |
139 | return NEUTRAL_B; | |
e342a24d EZ |
140 | if (ch < 0 || ch > MAX_CHAR) |
141 | abort (); | |
6bff6497 EZ |
142 | |
143 | default_type = (bidi_type_t) XINT (CHAR_TABLE_REF (bidi_type_table, ch)); | |
144 | ||
145 | if (override == NEUTRAL_DIR) | |
146 | return default_type; | |
147 | ||
148 | switch (default_type) | |
149 | { | |
150 | /* Although UAX#9 does not tell, it doesn't make sense to | |
151 | override NEUTRAL_B and LRM/RLM characters. */ | |
152 | case NEUTRAL_B: | |
153 | case LRE: | |
154 | case LRO: | |
155 | case RLE: | |
156 | case RLO: | |
157 | case PDF: | |
158 | return default_type; | |
159 | default: | |
160 | switch (ch) | |
161 | { | |
162 | case LRM_CHAR: | |
163 | case RLM_CHAR: | |
164 | return default_type; | |
165 | default: | |
166 | if (override == L2R) /* X6 */ | |
167 | return STRONG_L; | |
168 | else if (override == R2L) | |
169 | return STRONG_R; | |
170 | else | |
171 | abort (); /* can't happen: handled above */ | |
172 | } | |
173 | } | |
b7b65b15 EZ |
174 | } |
175 | ||
7d3b3862 | 176 | static void |
2d6e4628 EZ |
177 | bidi_check_type (bidi_type_t type) |
178 | { | |
179 | if (type < UNKNOWN_BT || type > NEUTRAL_ON) | |
180 | abort (); | |
181 | } | |
182 | ||
b7b65b15 | 183 | /* Given a bidi TYPE of a character, return its category. */ |
fd3998ff | 184 | static INLINE bidi_category_t |
b7b65b15 EZ |
185 | bidi_get_category (bidi_type_t type) |
186 | { | |
187 | switch (type) | |
188 | { | |
189 | case UNKNOWN_BT: | |
190 | return UNKNOWN_BC; | |
191 | case STRONG_L: | |
192 | case STRONG_R: | |
193 | case STRONG_AL: | |
194 | case LRE: | |
195 | case LRO: | |
196 | case RLE: | |
197 | case RLO: | |
198 | return STRONG; | |
199 | case PDF: /* ??? really?? */ | |
200 | case WEAK_EN: | |
201 | case WEAK_ES: | |
202 | case WEAK_ET: | |
203 | case WEAK_AN: | |
204 | case WEAK_CS: | |
205 | case WEAK_NSM: | |
206 | case WEAK_BN: | |
207 | return WEAK; | |
208 | case NEUTRAL_B: | |
209 | case NEUTRAL_S: | |
210 | case NEUTRAL_WS: | |
211 | case NEUTRAL_ON: | |
212 | return NEUTRAL; | |
213 | default: | |
214 | abort (); | |
215 | } | |
216 | } | |
217 | ||
a6e8d97c EZ |
218 | /* Return the mirrored character of C, if it has one. If C has no |
219 | mirrored counterpart, return C. | |
220 | Note: The conditions in UAX#9 clause L4 regarding the surrounding | |
221 | context must be tested by the caller. */ | |
b7b65b15 EZ |
222 | int |
223 | bidi_mirror_char (int c) | |
224 | { | |
cbc4fd20 EZ |
225 | Lisp_Object val; |
226 | ||
227 | if (c == BIDI_EOB) | |
228 | return c; | |
229 | if (c < 0 || c > MAX_CHAR) | |
230 | abort (); | |
b7b65b15 | 231 | |
cbc4fd20 EZ |
232 | val = CHAR_TABLE_REF (bidi_mirror_table, c); |
233 | if (INTEGERP (val)) | |
b7b65b15 | 234 | { |
cbc4fd20 | 235 | int v = XINT (val); |
b7b65b15 | 236 | |
cbc4fd20 EZ |
237 | if (v < 0 || v > MAX_CHAR) |
238 | abort (); | |
239 | ||
240 | return v; | |
b7b65b15 | 241 | } |
cbc4fd20 | 242 | |
b7b65b15 EZ |
243 | return c; |
244 | } | |
245 | ||
246 | /* Copy the bidi iterator from FROM to TO. To save cycles, this only | |
247 | copies the part of the level stack that is actually in use. */ | |
fd3998ff | 248 | static INLINE void |
b7b65b15 EZ |
249 | bidi_copy_it (struct bidi_it *to, struct bidi_it *from) |
250 | { | |
251 | int i; | |
252 | ||
e69a9370 | 253 | /* Copy everything except the level stack and beyond. */ |
182ce2d2 | 254 | memcpy (to, from, offsetof (struct bidi_it, level_stack[0])); |
b7b65b15 EZ |
255 | |
256 | /* Copy the active part of the level stack. */ | |
257 | to->level_stack[0] = from->level_stack[0]; /* level zero is always in use */ | |
258 | for (i = 1; i <= from->stack_idx; i++) | |
259 | to->level_stack[i] = from->level_stack[i]; | |
260 | } | |
261 | ||
262 | /* Caching the bidi iterator states. */ | |
263 | ||
2fe72643 EZ |
264 | #define BIDI_CACHE_CHUNK 200 |
265 | static struct bidi_it *bidi_cache; | |
266 | static size_t bidi_cache_size = 0; | |
0416466c | 267 | static size_t elsz = sizeof (struct bidi_it); |
2fe72643 EZ |
268 | static int bidi_cache_idx; /* next unused cache slot */ |
269 | static int bidi_cache_last_idx; /* slot of last cache hit */ | |
b7b65b15 | 270 | |
fd3998ff | 271 | static INLINE void |
b7b65b15 EZ |
272 | bidi_cache_reset (void) |
273 | { | |
274 | bidi_cache_idx = 0; | |
275 | bidi_cache_last_idx = -1; | |
276 | } | |
277 | ||
2fe72643 EZ |
278 | static INLINE void |
279 | bidi_cache_shrink (void) | |
280 | { | |
281 | if (bidi_cache_size > BIDI_CACHE_CHUNK) | |
282 | { | |
0416466c EZ |
283 | bidi_cache_size = BIDI_CACHE_CHUNK; |
284 | bidi_cache = | |
285 | (struct bidi_it *) xrealloc (bidi_cache, bidi_cache_size * elsz); | |
2fe72643 EZ |
286 | } |
287 | bidi_cache_reset (); | |
288 | } | |
289 | ||
fd3998ff | 290 | static INLINE void |
b7b65b15 EZ |
291 | bidi_cache_fetch_state (int idx, struct bidi_it *bidi_it) |
292 | { | |
293 | int current_scan_dir = bidi_it->scan_dir; | |
294 | ||
295 | if (idx < 0 || idx >= bidi_cache_idx) | |
296 | abort (); | |
297 | ||
298 | bidi_copy_it (bidi_it, &bidi_cache[idx]); | |
299 | bidi_it->scan_dir = current_scan_dir; | |
300 | bidi_cache_last_idx = idx; | |
301 | } | |
302 | ||
303 | /* Find a cached state with a given CHARPOS and resolved embedding | |
304 | level less or equal to LEVEL. if LEVEL is -1, disregard the | |
305 | resolved levels in cached states. DIR, if non-zero, means search | |
306 | in that direction from the last cache hit. */ | |
fd3998ff | 307 | static INLINE int |
61bfec98 | 308 | bidi_cache_search (EMACS_INT charpos, int level, int dir) |
b7b65b15 EZ |
309 | { |
310 | int i, i_start; | |
311 | ||
312 | if (bidi_cache_idx) | |
313 | { | |
314 | if (charpos < bidi_cache[bidi_cache_last_idx].charpos) | |
182ce2d2 EZ |
315 | { |
316 | dir = -1; | |
317 | i_start = bidi_cache_last_idx - 1; | |
318 | } | |
319 | else if (charpos > (bidi_cache[bidi_cache_last_idx].charpos | |
320 | + bidi_cache[bidi_cache_last_idx].nchars - 1)) | |
321 | { | |
322 | dir = 1; | |
323 | i_start = bidi_cache_last_idx + 1; | |
324 | } | |
325 | else if (dir) | |
b7b65b15 EZ |
326 | i_start = bidi_cache_last_idx; |
327 | else | |
328 | { | |
329 | dir = -1; | |
330 | i_start = bidi_cache_idx - 1; | |
331 | } | |
332 | ||
333 | if (dir < 0) | |
334 | { | |
335 | /* Linear search for now; FIXME! */ | |
336 | for (i = i_start; i >= 0; i--) | |
182ce2d2 EZ |
337 | if (bidi_cache[i].charpos <= charpos |
338 | && charpos < bidi_cache[i].charpos + bidi_cache[i].nchars | |
b7b65b15 EZ |
339 | && (level == -1 || bidi_cache[i].resolved_level <= level)) |
340 | return i; | |
341 | } | |
342 | else | |
343 | { | |
344 | for (i = i_start; i < bidi_cache_idx; i++) | |
182ce2d2 EZ |
345 | if (bidi_cache[i].charpos <= charpos |
346 | && charpos < bidi_cache[i].charpos + bidi_cache[i].nchars | |
b7b65b15 EZ |
347 | && (level == -1 || bidi_cache[i].resolved_level <= level)) |
348 | return i; | |
349 | } | |
350 | } | |
351 | ||
352 | return -1; | |
353 | } | |
354 | ||
355 | /* Find a cached state where the resolved level changes to a value | |
356 | that is lower than LEVEL, and return its cache slot index. DIR is | |
357 | the direction to search, starting with the last used cache slot. | |
358 | BEFORE, if non-zero, means return the index of the slot that is | |
359 | ``before'' the level change in the search direction. That is, | |
360 | given the cached levels like this: | |
361 | ||
362 | 1122333442211 | |
363 | AB C | |
364 | ||
365 | and assuming we are at the position cached at the slot marked with | |
366 | C, searching backwards (DIR = -1) for LEVEL = 2 will return the | |
367 | index of slot B or A, depending whether BEFORE is, respectively, | |
368 | non-zero or zero. */ | |
369 | static int | |
370 | bidi_cache_find_level_change (int level, int dir, int before) | |
371 | { | |
372 | if (bidi_cache_idx) | |
373 | { | |
374 | int i = dir ? bidi_cache_last_idx : bidi_cache_idx - 1; | |
375 | int incr = before ? 1 : 0; | |
376 | ||
377 | if (!dir) | |
378 | dir = -1; | |
379 | else if (!incr) | |
380 | i += dir; | |
381 | ||
382 | if (dir < 0) | |
383 | { | |
384 | while (i >= incr) | |
385 | { | |
386 | if (bidi_cache[i - incr].resolved_level >= 0 | |
387 | && bidi_cache[i - incr].resolved_level < level) | |
388 | return i; | |
389 | i--; | |
390 | } | |
391 | } | |
392 | else | |
393 | { | |
394 | while (i < bidi_cache_idx - incr) | |
395 | { | |
396 | if (bidi_cache[i + incr].resolved_level >= 0 | |
397 | && bidi_cache[i + incr].resolved_level < level) | |
398 | return i; | |
399 | i++; | |
400 | } | |
401 | } | |
402 | } | |
403 | ||
404 | return -1; | |
405 | } | |
406 | ||
fd3998ff | 407 | static INLINE void |
b7b65b15 EZ |
408 | bidi_cache_iterator_state (struct bidi_it *bidi_it, int resolved) |
409 | { | |
410 | int idx; | |
411 | ||
412 | /* We should never cache on backward scans. */ | |
413 | if (bidi_it->scan_dir == -1) | |
414 | abort (); | |
415 | idx = bidi_cache_search (bidi_it->charpos, -1, 1); | |
416 | ||
417 | if (idx < 0) | |
418 | { | |
419 | idx = bidi_cache_idx; | |
2fe72643 EZ |
420 | /* Enlarge the cache as needed. */ |
421 | if (idx >= bidi_cache_size) | |
422 | { | |
0416466c | 423 | bidi_cache_size += BIDI_CACHE_CHUNK; |
2fe72643 | 424 | bidi_cache = |
0416466c | 425 | (struct bidi_it *) xrealloc (bidi_cache, bidi_cache_size * elsz); |
2fe72643 | 426 | } |
bd924a5d EZ |
427 | /* Character positions should correspond to cache positions 1:1. |
428 | If we are outside the range of cached positions, the cache is | |
429 | useless and must be reset. */ | |
430 | if (idx > 0 && | |
182ce2d2 EZ |
431 | (bidi_it->charpos > (bidi_cache[idx - 1].charpos |
432 | + bidi_cache[idx - 1].nchars) | |
bd924a5d EZ |
433 | || bidi_it->charpos < bidi_cache[0].charpos)) |
434 | { | |
435 | bidi_cache_reset (); | |
436 | idx = 0; | |
437 | } | |
102ebb00 EZ |
438 | if (bidi_it->nchars <= 0) |
439 | abort (); | |
b7b65b15 EZ |
440 | bidi_copy_it (&bidi_cache[idx], bidi_it); |
441 | if (!resolved) | |
442 | bidi_cache[idx].resolved_level = -1; | |
443 | } | |
444 | else | |
445 | { | |
446 | /* Copy only the members which could have changed, to avoid | |
447 | costly copying of the entire struct. */ | |
448 | bidi_cache[idx].type = bidi_it->type; | |
2d6e4628 | 449 | bidi_check_type (bidi_it->type); |
89d3374a EZ |
450 | bidi_cache[idx].type_after_w1 = bidi_it->type_after_w1; |
451 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 EZ |
452 | if (resolved) |
453 | bidi_cache[idx].resolved_level = bidi_it->resolved_level; | |
454 | else | |
455 | bidi_cache[idx].resolved_level = -1; | |
456 | bidi_cache[idx].invalid_levels = bidi_it->invalid_levels; | |
457 | bidi_cache[idx].invalid_rl_levels = bidi_it->invalid_rl_levels; | |
458 | bidi_cache[idx].next_for_neutral = bidi_it->next_for_neutral; | |
459 | bidi_cache[idx].next_for_ws = bidi_it->next_for_ws; | |
460 | bidi_cache[idx].ignore_bn_limit = bidi_it->ignore_bn_limit; | |
461 | } | |
462 | ||
463 | bidi_cache_last_idx = idx; | |
464 | if (idx >= bidi_cache_idx) | |
465 | bidi_cache_idx = idx + 1; | |
466 | } | |
467 | ||
fd3998ff | 468 | static INLINE bidi_type_t |
61bfec98 | 469 | bidi_cache_find (EMACS_INT charpos, int level, struct bidi_it *bidi_it) |
b7b65b15 EZ |
470 | { |
471 | int i = bidi_cache_search (charpos, level, bidi_it->scan_dir); | |
472 | ||
473 | if (i >= 0) | |
474 | { | |
475 | bidi_dir_t current_scan_dir = bidi_it->scan_dir; | |
476 | ||
5009f85e | 477 | bidi_copy_it (bidi_it, &bidi_cache[i]); |
b7b65b15 EZ |
478 | bidi_cache_last_idx = i; |
479 | /* Don't let scan direction from from the cached state override | |
480 | the current scan direction. */ | |
481 | bidi_it->scan_dir = current_scan_dir; | |
482 | return bidi_it->type; | |
483 | } | |
484 | ||
485 | return UNKNOWN_BT; | |
486 | } | |
487 | ||
fd3998ff | 488 | static INLINE int |
b7b65b15 EZ |
489 | bidi_peek_at_next_level (struct bidi_it *bidi_it) |
490 | { | |
491 | if (bidi_cache_idx == 0 || bidi_cache_last_idx == -1) | |
492 | abort (); | |
493 | return bidi_cache[bidi_cache_last_idx + bidi_it->scan_dir].resolved_level; | |
494 | } | |
495 | ||
be39f003 EZ |
496 | /* Check if buffer position CHARPOS/BYTEPOS is the end of a paragraph. |
497 | Value is the non-negative length of the paragraph separator | |
498 | following the buffer position, -1 if position is at the beginning | |
499 | of a new paragraph, or -2 if position is neither at beginning nor | |
500 | at end of a paragraph. */ | |
fd3998ff | 501 | static EMACS_INT |
6bff6497 | 502 | bidi_at_paragraph_end (EMACS_INT charpos, EMACS_INT bytepos) |
b7b65b15 | 503 | { |
372b7a95 EZ |
504 | Lisp_Object sep_re; |
505 | Lisp_Object start_re; | |
be39f003 EZ |
506 | EMACS_INT val; |
507 | ||
372b7a95 EZ |
508 | sep_re = paragraph_separate_re; |
509 | start_re = paragraph_start_re; | |
be39f003 EZ |
510 | |
511 | val = fast_looking_at (sep_re, charpos, bytepos, ZV, ZV_BYTE, Qnil); | |
512 | if (val < 0) | |
513 | { | |
514 | if (fast_looking_at (start_re, charpos, bytepos, ZV, ZV_BYTE, Qnil) >= 0) | |
515 | val = -1; | |
516 | else | |
517 | val = -2; | |
518 | } | |
b7b65b15 | 519 | |
be39f003 | 520 | return val; |
b7b65b15 EZ |
521 | } |
522 | ||
523 | /* Determine the start-of-run (sor) directional type given the two | |
524 | embedding levels on either side of the run boundary. Also, update | |
525 | the saved info about previously seen characters, since that info is | |
526 | generally valid for a single level run. */ | |
fd3998ff | 527 | static INLINE void |
b7b65b15 EZ |
528 | bidi_set_sor_type (struct bidi_it *bidi_it, int level_before, int level_after) |
529 | { | |
530 | int higher_level = level_before > level_after ? level_before : level_after; | |
531 | ||
532 | /* The prev_was_pdf gork is required for when we have several PDFs | |
533 | in a row. In that case, we want to compute the sor type for the | |
534 | next level run only once: when we see the first PDF. That's | |
535 | because the sor type depends only on the higher of the two levels | |
536 | that we find on the two sides of the level boundary (see UAX#9, | |
537 | clause X10), and so we don't need to know the final embedding | |
538 | level to which we descend after processing all the PDFs. */ | |
e342a24d | 539 | if (!bidi_it->prev_was_pdf || level_before < level_after) |
b7b65b15 EZ |
540 | /* FIXME: should the default sor direction be user selectable? */ |
541 | bidi_it->sor = (higher_level & 1) != 0 ? R2L : L2R; | |
542 | if (level_before > level_after) | |
543 | bidi_it->prev_was_pdf = 1; | |
544 | ||
545 | bidi_it->prev.type = UNKNOWN_BT; | |
89d3374a EZ |
546 | bidi_it->last_strong.type = bidi_it->last_strong.type_after_w1 = |
547 | bidi_it->last_strong.orig_type = UNKNOWN_BT; | |
b7b65b15 EZ |
548 | bidi_it->prev_for_neutral.type = bidi_it->sor == R2L ? STRONG_R : STRONG_L; |
549 | bidi_it->prev_for_neutral.charpos = bidi_it->charpos; | |
550 | bidi_it->prev_for_neutral.bytepos = bidi_it->bytepos; | |
89d3374a EZ |
551 | bidi_it->next_for_neutral.type = bidi_it->next_for_neutral.type_after_w1 = |
552 | bidi_it->next_for_neutral.orig_type = UNKNOWN_BT; | |
b7b65b15 EZ |
553 | bidi_it->ignore_bn_limit = 0; /* meaning it's unknown */ |
554 | } | |
555 | ||
182ce2d2 | 556 | /* Perform initializations for reordering a new line of bidi text. */ |
6bff6497 | 557 | static void |
be39f003 EZ |
558 | bidi_line_init (struct bidi_it *bidi_it) |
559 | { | |
560 | bidi_it->scan_dir = 1; /* FIXME: do we need to have control on this? */ | |
561 | bidi_it->resolved_level = bidi_it->level_stack[0].level; | |
562 | bidi_it->level_stack[0].override = NEUTRAL_DIR; /* X1 */ | |
563 | bidi_it->invalid_levels = 0; | |
564 | bidi_it->invalid_rl_levels = -1; | |
565 | bidi_it->next_en_pos = -1; | |
566 | bidi_it->next_for_ws.type = UNKNOWN_BT; | |
b44d9321 EZ |
567 | bidi_set_sor_type (bidi_it, |
568 | bidi_it->paragraph_dir == R2L ? 1 : 0, | |
be39f003 EZ |
569 | bidi_it->level_stack[0].level); /* X10 */ |
570 | ||
571 | bidi_cache_reset (); | |
572 | } | |
573 | ||
102ebb00 EZ |
574 | /* Fetch and return the character at BYTEPOS/CHARPOS. If that |
575 | character is covered by a display string, treat the entire run of | |
576 | covered characters as a single character u+FFFC, and return their | |
577 | combined length in CH_LEN and NCHARS. DISP_POS specifies the | |
578 | character position of the next display string, or -1 if not yet | |
579 | computed. When the next character is at or beyond that position, | |
580 | the function updates DISP_POS with the position of the next display | |
581 | string. */ | |
182ce2d2 | 582 | static INLINE int |
102ebb00 | 583 | bidi_fetch_char (EMACS_INT bytepos, EMACS_INT charpos, EMACS_INT *disp_pos, |
182ce2d2 EZ |
584 | EMACS_INT *ch_len, EMACS_INT *nchars) |
585 | { | |
586 | int ch; | |
587 | ||
588 | /* FIXME: Support strings in addition to buffers. */ | |
589 | /* If we got past the last known position of display string, compute | |
590 | the position of the next one. That position could be at BYTEPOS. */ | |
102ebb00 EZ |
591 | if (charpos < ZV && charpos > *disp_pos) |
592 | *disp_pos = compute_display_string_pos (charpos); | |
593 | ||
594 | /* Fetch the character at BYTEPOS. */ | |
182ce2d2 EZ |
595 | if (bytepos >= ZV_BYTE) |
596 | { | |
597 | ch = BIDI_EOB; | |
598 | *ch_len = 1; | |
599 | *nchars = 1; | |
600 | } | |
601 | #if 0 | |
102ebb00 | 602 | else if (charpos >= *disp_pos) |
182ce2d2 EZ |
603 | { |
604 | /* support characters covered by a display string */ | |
605 | ch = 0xFFFC; /* Unicode Object Replacement Character */ | |
606 | } | |
607 | #endif | |
608 | else | |
609 | { | |
610 | ch = FETCH_MULTIBYTE_CHAR (bytepos); | |
611 | *ch_len = CHAR_BYTES (ch); | |
612 | *nchars = 1; | |
613 | } | |
614 | ||
615 | /* If we just entered a run of characters covered by a display | |
616 | string, compute the position of the next display string. */ | |
102ebb00 EZ |
617 | if (charpos + *nchars <= ZV && charpos + *nchars > *disp_pos) |
618 | *disp_pos = compute_display_string_pos (charpos + *nchars); | |
182ce2d2 EZ |
619 | |
620 | return ch; | |
621 | } | |
622 | ||
623 | /* Looks like we won't need this one. */ | |
624 | #if 0 | |
625 | /* Fetch character at CHARPOS/BYTEPOS. Return the character, and | |
626 | advance CHARPOS and BYTEPOS to the next character in logical | |
627 | order. */ | |
628 | static INLINE int | |
629 | bidi_fetch_char_advance (EMACS_INT *charpos, EMACS_INT *bytepos) | |
630 | { | |
631 | int ch; | |
632 | ||
633 | /* FIXME: Support strings in addition to buffers. */ | |
634 | FETCH_CHAR_ADVANCE_NO_CHECK (ch, charpos, bytepos); | |
635 | ||
636 | #if 0 | |
637 | if (...) | |
638 | { | |
639 | /* FIXME: Support characters covered by display strings. */ | |
640 | ch = 0xFFFC; | |
641 | } | |
642 | #endif | |
643 | ||
644 | return ch; | |
645 | } | |
646 | #endif | |
647 | ||
be39f003 EZ |
648 | /* Find the beginning of this paragraph by looking back in the buffer. |
649 | Value is the byte position of the paragraph's beginning. */ | |
650 | static EMACS_INT | |
b44d9321 | 651 | bidi_find_paragraph_start (EMACS_INT pos, EMACS_INT pos_byte) |
6bff6497 | 652 | { |
372b7a95 | 653 | Lisp_Object re = paragraph_start_re; |
6bff6497 EZ |
654 | EMACS_INT limit = ZV, limit_byte = ZV_BYTE; |
655 | ||
6bff6497 EZ |
656 | while (pos_byte > BEGV_BYTE |
657 | && fast_looking_at (re, pos, pos_byte, limit, limit_byte, Qnil) < 0) | |
658 | { | |
182ce2d2 EZ |
659 | /* FIXME: What if the paragraph beginning is covered by a |
660 | display string? And what if a display string covering some | |
661 | of the text over which we scan back includes | |
662 | paragraph_start_re? */ | |
be39f003 EZ |
663 | pos = find_next_newline_no_quit (pos - 1, -1); |
664 | pos_byte = CHAR_TO_BYTE (pos); | |
6bff6497 | 665 | } |
be39f003 | 666 | return pos_byte; |
6bff6497 EZ |
667 | } |
668 | ||
bea4f10c | 669 | /* Determine the base direction, a.k.a. base embedding level, of the |
b44d9321 EZ |
670 | paragraph we are about to iterate through. If DIR is either L2R or |
671 | R2L, just use that. Otherwise, determine the paragraph direction | |
bea4f10c EZ |
672 | from the first strong directional character of the paragraph. |
673 | ||
182ce2d2 | 674 | NO_DEFAULT_P non-zero means don't default to L2R if the paragraph |
bea4f10c EZ |
675 | has no strong directional characters and both DIR and |
676 | bidi_it->paragraph_dir are NEUTRAL_DIR. In that case, search back | |
677 | in the buffer until a paragraph is found with a strong character, | |
678 | or until hitting BEGV. In the latter case, fall back to L2R. This | |
679 | flag is used in current-bidi-paragraph-direction. | |
680 | ||
681 | Note that this function gives the paragraph separator the same | |
682 | direction as the preceding paragraph, even though Emacs generally | |
683 | views the separartor as not belonging to any paragraph. */ | |
b7b65b15 | 684 | void |
bea4f10c | 685 | bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, int no_default_p) |
b7b65b15 | 686 | { |
6bff6497 | 687 | EMACS_INT bytepos = bidi_it->bytepos; |
bea4f10c | 688 | EMACS_INT pstartbyte; |
e7402cb2 | 689 | |
5e65aec0 EZ |
690 | /* Special case for an empty buffer. */ |
691 | if (bytepos == BEGV_BYTE && bytepos == ZV_BYTE) | |
692 | dir = L2R; | |
9c82e145 | 693 | /* We should never be called at EOB or before BEGV. */ |
5e65aec0 | 694 | else if (bytepos >= ZV_BYTE || bytepos < BEGV_BYTE) |
9c82e145 EZ |
695 | abort (); |
696 | ||
be39f003 EZ |
697 | if (dir == L2R) |
698 | { | |
699 | bidi_it->paragraph_dir = L2R; | |
700 | bidi_it->new_paragraph = 0; | |
701 | } | |
702 | else if (dir == R2L) | |
703 | { | |
704 | bidi_it->paragraph_dir = R2L; | |
705 | bidi_it->new_paragraph = 0; | |
706 | } | |
b7b65b15 EZ |
707 | else if (dir == NEUTRAL_DIR) /* P2 */ |
708 | { | |
182ce2d2 EZ |
709 | int ch; |
710 | EMACS_INT ch_len, nchars; | |
711 | EMACS_INT pos, disp_pos = -1; | |
6bff6497 | 712 | bidi_type_t type; |
be39f003 | 713 | |
d20e1419 EZ |
714 | if (!bidi_initialized) |
715 | bidi_initialize (); | |
716 | ||
be39f003 EZ |
717 | /* If we are inside a paragraph separator, we are just waiting |
718 | for the separator to be exhausted; use the previous paragraph | |
e5a2fec7 EZ |
719 | direction. But don't do that if we have been just reseated, |
720 | because we need to reinitialize below in that case. */ | |
721 | if (!bidi_it->first_elt | |
722 | && bidi_it->charpos < bidi_it->separator_limit) | |
be39f003 EZ |
723 | return; |
724 | ||
b44d9321 | 725 | /* If we are on a newline, get past it to where the next |
5e65aec0 EZ |
726 | paragraph might start. But don't do that at BEGV since then |
727 | we are potentially in a new paragraph that doesn't yet | |
728 | exist. */ | |
c143c213 | 729 | pos = bidi_it->charpos; |
5e65aec0 | 730 | if (bytepos > BEGV_BYTE && FETCH_CHAR (bytepos) == '\n') |
be39f003 | 731 | { |
b44d9321 | 732 | bytepos++; |
c143c213 | 733 | pos++; |
be39f003 | 734 | } |
b44d9321 EZ |
735 | |
736 | /* We are either at the beginning of a paragraph or in the | |
737 | middle of it. Find where this paragraph starts. */ | |
bea4f10c | 738 | pstartbyte = bidi_find_paragraph_start (pos, bytepos); |
be39f003 EZ |
739 | bidi_it->separator_limit = -1; |
740 | bidi_it->new_paragraph = 0; | |
bea4f10c EZ |
741 | |
742 | /* The following loop is run more than once only if NO_DEFAULT_P | |
743 | is non-zero. */ | |
744 | do { | |
745 | bytepos = pstartbyte; | |
bea4f10c | 746 | pos = BYTE_TO_CHAR (bytepos); |
102ebb00 | 747 | ch = bidi_fetch_char (bytepos, pos, &disp_pos, &ch_len, &nchars); |
bea4f10c EZ |
748 | type = bidi_get_type (ch, NEUTRAL_DIR); |
749 | ||
182ce2d2 | 750 | for (pos += nchars, bytepos += ch_len; |
bea4f10c EZ |
751 | /* NOTE: UAX#9 says to search only for L, AL, or R types |
752 | of characters, and ignore RLE, RLO, LRE, and LRO. | |
753 | However, I'm not sure it makes sense to omit those 4; | |
754 | should try with and without that to see the effect. */ | |
755 | (bidi_get_category (type) != STRONG) | |
756 | || (bidi_ignore_explicit_marks_for_paragraph_level | |
757 | && (type == RLE || type == RLO | |
758 | || type == LRE || type == LRO)); | |
759 | type = bidi_get_type (ch, NEUTRAL_DIR)) | |
760 | { | |
761 | if (type == NEUTRAL_B && bidi_at_paragraph_end (pos, bytepos) >= -1) | |
21fce5ab | 762 | break; |
bea4f10c EZ |
763 | if (bytepos >= ZV_BYTE) |
764 | { | |
765 | /* Pretend there's a paragraph separator at end of | |
766 | buffer. */ | |
767 | type = NEUTRAL_B; | |
768 | break; | |
769 | } | |
102ebb00 EZ |
770 | /* Fetch next character and advance to get past it. */ |
771 | ch = bidi_fetch_char (bytepos, pos, &disp_pos, &ch_len, &nchars); | |
182ce2d2 EZ |
772 | pos += nchars; |
773 | bytepos += ch_len; | |
bea4f10c EZ |
774 | } |
775 | if (type == STRONG_R || type == STRONG_AL) /* P3 */ | |
776 | bidi_it->paragraph_dir = R2L; | |
777 | else if (type == STRONG_L) | |
778 | bidi_it->paragraph_dir = L2R; | |
779 | if (no_default_p && bidi_it->paragraph_dir == NEUTRAL_DIR) | |
780 | { | |
781 | /* If this paragraph is at BEGV, default to L2R. */ | |
782 | if (pstartbyte == BEGV_BYTE) | |
783 | bidi_it->paragraph_dir = L2R; /* P3 and HL1 */ | |
784 | else | |
785 | { | |
786 | EMACS_INT prevpbyte = pstartbyte; | |
787 | EMACS_INT p = BYTE_TO_CHAR (pstartbyte), pbyte = pstartbyte; | |
788 | ||
789 | /* Find the beginning of the previous paragraph, if any. */ | |
790 | while (pbyte > BEGV_BYTE && prevpbyte >= pstartbyte) | |
791 | { | |
182ce2d2 EZ |
792 | /* FXIME: What if p is covered by a display |
793 | string? See also a FIXME inside | |
794 | bidi_find_paragraph_start. */ | |
bea4f10c EZ |
795 | p--; |
796 | pbyte = CHAR_TO_BYTE (p); | |
797 | prevpbyte = bidi_find_paragraph_start (p, pbyte); | |
798 | } | |
799 | pstartbyte = prevpbyte; | |
800 | } | |
801 | } | |
802 | } while (no_default_p && bidi_it->paragraph_dir == NEUTRAL_DIR); | |
b7b65b15 | 803 | } |
be39f003 EZ |
804 | else |
805 | abort (); | |
b7b65b15 | 806 | |
b44d9321 EZ |
807 | /* Contrary to UAX#9 clause P3, we only default the paragraph |
808 | direction to L2R if we have no previous usable paragraph | |
bea4f10c | 809 | direction. This is allowed by the HL1 clause. */ |
d20e1419 | 810 | if (bidi_it->paragraph_dir != L2R && bidi_it->paragraph_dir != R2L) |
bea4f10c | 811 | bidi_it->paragraph_dir = L2R; /* P3 and HL1 ``higher-level protocols'' */ |
be39f003 | 812 | if (bidi_it->paragraph_dir == R2L) |
b44d9321 | 813 | bidi_it->level_stack[0].level = 1; |
be39f003 | 814 | else |
b44d9321 | 815 | bidi_it->level_stack[0].level = 0; |
be39f003 EZ |
816 | |
817 | bidi_line_init (bidi_it); | |
b7b65b15 EZ |
818 | } |
819 | ||
6bff6497 EZ |
820 | /* Do whatever UAX#9 clause X8 says should be done at paragraph's |
821 | end. */ | |
fd3998ff | 822 | static INLINE void |
b7b65b15 EZ |
823 | bidi_set_paragraph_end (struct bidi_it *bidi_it) |
824 | { | |
825 | bidi_it->invalid_levels = 0; | |
826 | bidi_it->invalid_rl_levels = -1; | |
827 | bidi_it->stack_idx = 0; | |
828 | bidi_it->resolved_level = bidi_it->level_stack[0].level; | |
b7b65b15 EZ |
829 | } |
830 | ||
182ce2d2 | 831 | /* Initialize the bidi iterator from buffer/string position CHARPOS. */ |
b7b65b15 | 832 | void |
6bff6497 | 833 | bidi_init_it (EMACS_INT charpos, EMACS_INT bytepos, struct bidi_it *bidi_it) |
b7b65b15 EZ |
834 | { |
835 | if (! bidi_initialized) | |
836 | bidi_initialize (); | |
89d3374a EZ |
837 | bidi_it->charpos = charpos; |
838 | bidi_it->bytepos = bytepos; | |
182ce2d2 | 839 | bidi_it->nchars = -1; /* to be computed in bidi_resolve_explicit_1 */ |
6bff6497 EZ |
840 | bidi_it->first_elt = 1; |
841 | bidi_set_paragraph_end (bidi_it); | |
842 | bidi_it->new_paragraph = 1; | |
be39f003 | 843 | bidi_it->separator_limit = -1; |
b7b65b15 | 844 | bidi_it->type = NEUTRAL_B; |
ebb5722e EZ |
845 | bidi_it->type_after_w1 = NEUTRAL_B; |
846 | bidi_it->orig_type = NEUTRAL_B; | |
b7b65b15 | 847 | bidi_it->prev_was_pdf = 0; |
ebb5722e EZ |
848 | bidi_it->prev.type = bidi_it->prev.type_after_w1 = |
849 | bidi_it->prev.orig_type = UNKNOWN_BT; | |
89d3374a EZ |
850 | bidi_it->last_strong.type = bidi_it->last_strong.type_after_w1 = |
851 | bidi_it->last_strong.orig_type = UNKNOWN_BT; | |
b7b65b15 EZ |
852 | bidi_it->next_for_neutral.charpos = -1; |
853 | bidi_it->next_for_neutral.type = | |
89d3374a EZ |
854 | bidi_it->next_for_neutral.type_after_w1 = |
855 | bidi_it->next_for_neutral.orig_type = UNKNOWN_BT; | |
b7b65b15 EZ |
856 | bidi_it->prev_for_neutral.charpos = -1; |
857 | bidi_it->prev_for_neutral.type = | |
89d3374a EZ |
858 | bidi_it->prev_for_neutral.type_after_w1 = |
859 | bidi_it->prev_for_neutral.orig_type = UNKNOWN_BT; | |
b7b65b15 | 860 | bidi_it->sor = L2R; /* FIXME: should it be user-selectable? */ |
182ce2d2 | 861 | bidi_it->disp_pos = -1; /* invalid/unknown */ |
2fe72643 | 862 | bidi_cache_shrink (); |
b7b65b15 EZ |
863 | } |
864 | ||
865 | /* Push the current embedding level and override status; reset the | |
866 | current level to LEVEL and the current override status to OVERRIDE. */ | |
fd3998ff | 867 | static INLINE void |
b7b65b15 EZ |
868 | bidi_push_embedding_level (struct bidi_it *bidi_it, |
869 | int level, bidi_dir_t override) | |
870 | { | |
871 | bidi_it->stack_idx++; | |
872 | if (bidi_it->stack_idx >= BIDI_MAXLEVEL) | |
873 | abort (); | |
874 | bidi_it->level_stack[bidi_it->stack_idx].level = level; | |
875 | bidi_it->level_stack[bidi_it->stack_idx].override = override; | |
876 | } | |
877 | ||
878 | /* Pop the embedding level and directional override status from the | |
879 | stack, and return the new level. */ | |
fd3998ff | 880 | static INLINE int |
b7b65b15 EZ |
881 | bidi_pop_embedding_level (struct bidi_it *bidi_it) |
882 | { | |
883 | /* UAX#9 says to ignore invalid PDFs. */ | |
884 | if (bidi_it->stack_idx > 0) | |
885 | bidi_it->stack_idx--; | |
886 | return bidi_it->level_stack[bidi_it->stack_idx].level; | |
887 | } | |
888 | ||
889 | /* Record in SAVED_INFO the information about the current character. */ | |
fd3998ff | 890 | static INLINE void |
b7b65b15 EZ |
891 | bidi_remember_char (struct bidi_saved_info *saved_info, |
892 | struct bidi_it *bidi_it) | |
893 | { | |
894 | saved_info->charpos = bidi_it->charpos; | |
895 | saved_info->bytepos = bidi_it->bytepos; | |
896 | saved_info->type = bidi_it->type; | |
2d6e4628 | 897 | bidi_check_type (bidi_it->type); |
89d3374a EZ |
898 | saved_info->type_after_w1 = bidi_it->type_after_w1; |
899 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 | 900 | saved_info->orig_type = bidi_it->orig_type; |
2d6e4628 | 901 | bidi_check_type (bidi_it->orig_type); |
b7b65b15 EZ |
902 | } |
903 | ||
904 | /* Resolve the type of a neutral character according to the type of | |
905 | surrounding strong text and the current embedding level. */ | |
fd3998ff | 906 | static INLINE bidi_type_t |
b7b65b15 EZ |
907 | bidi_resolve_neutral_1 (bidi_type_t prev_type, bidi_type_t next_type, int lev) |
908 | { | |
909 | /* N1: European and Arabic numbers are treated as though they were R. */ | |
910 | if (next_type == WEAK_EN || next_type == WEAK_AN) | |
911 | next_type = STRONG_R; | |
912 | if (prev_type == WEAK_EN || prev_type == WEAK_AN) | |
913 | prev_type = STRONG_R; | |
914 | ||
915 | if (next_type == prev_type) /* N1 */ | |
916 | return next_type; | |
917 | else if ((lev & 1) == 0) /* N2 */ | |
918 | return STRONG_L; | |
919 | else | |
920 | return STRONG_R; | |
921 | } | |
922 | ||
fd3998ff | 923 | static INLINE int |
182ce2d2 | 924 | bidi_explicit_dir_char (int ch) |
b7b65b15 | 925 | { |
182ce2d2 EZ |
926 | bidi_type_t ch_type; |
927 | ||
928 | if (!bidi_initialized) | |
929 | abort (); | |
930 | ch_type = (bidi_type_t) XINT (CHAR_TABLE_REF (bidi_type_table, ch)); | |
931 | return (ch_type == LRE || ch_type == LRO | |
932 | || ch_type == RLE || ch_type == RLO | |
933 | || ch_type == PDF); | |
b7b65b15 EZ |
934 | } |
935 | ||
936 | /* A helper function for bidi_resolve_explicit. It advances to the | |
937 | next character in logical order and determines the new embedding | |
938 | level and directional override, but does not take into account | |
939 | empty embeddings. */ | |
940 | static int | |
941 | bidi_resolve_explicit_1 (struct bidi_it *bidi_it) | |
942 | { | |
943 | int curchar; | |
944 | bidi_type_t type; | |
945 | int current_level; | |
946 | int new_level; | |
947 | bidi_dir_t override; | |
948 | ||
182ce2d2 EZ |
949 | /* If reseat()'ed, don't advance, so as to start iteration from the |
950 | position where we were reseated. bidi_it->bytepos can be less | |
951 | than BEGV_BYTE after reseat to BEGV. */ | |
952 | if (bidi_it->bytepos < BEGV_BYTE | |
9c82e145 | 953 | || bidi_it->first_elt) |
e7402cb2 | 954 | { |
9c82e145 EZ |
955 | bidi_it->first_elt = 0; |
956 | if (bidi_it->charpos < BEGV) | |
957 | bidi_it->charpos = BEGV; | |
958 | bidi_it->bytepos = CHAR_TO_BYTE (bidi_it->charpos); | |
e7402cb2 | 959 | } |
9c82e145 | 960 | else if (bidi_it->bytepos < ZV_BYTE) /* don't move at ZV */ |
b7b65b15 | 961 | { |
182ce2d2 EZ |
962 | /* Advance to the next character, skipping characters covered by |
963 | display strings (nchars > 1). */ | |
102ebb00 EZ |
964 | if (bidi_it->nchars <= 0) |
965 | abort (); | |
182ce2d2 | 966 | bidi_it->charpos += bidi_it->nchars; |
e7402cb2 EZ |
967 | if (bidi_it->ch_len == 0) |
968 | abort (); | |
b7b65b15 EZ |
969 | bidi_it->bytepos += bidi_it->ch_len; |
970 | } | |
971 | ||
972 | current_level = bidi_it->level_stack[bidi_it->stack_idx].level; /* X1 */ | |
973 | override = bidi_it->level_stack[bidi_it->stack_idx].override; | |
974 | new_level = current_level; | |
975 | ||
e7402cb2 EZ |
976 | if (bidi_it->bytepos >= ZV_BYTE) |
977 | { | |
978 | curchar = BIDI_EOB; | |
979 | bidi_it->ch_len = 1; | |
182ce2d2 EZ |
980 | bidi_it->nchars = 1; |
981 | bidi_it->disp_pos = ZV_BYTE; | |
e7402cb2 EZ |
982 | } |
983 | else | |
984 | { | |
182ce2d2 EZ |
985 | /* Fetch the character at BYTEPOS. If it is covered by a |
986 | display string, treat the entire run of covered characters as | |
987 | a single character u+FFFC. */ | |
102ebb00 EZ |
988 | curchar = bidi_fetch_char (bidi_it->bytepos, bidi_it->charpos, |
989 | &bidi_it->disp_pos, | |
990 | &bidi_it->ch_len, &bidi_it->nchars); | |
e7402cb2 | 991 | } |
b7b65b15 | 992 | bidi_it->ch = curchar; |
b7b65b15 | 993 | |
6bff6497 EZ |
994 | /* Don't apply directional override here, as all the types we handle |
995 | below will not be affected by the override anyway, and we need | |
996 | the original type unaltered. The override will be applied in | |
997 | bidi_resolve_weak. */ | |
998 | type = bidi_get_type (curchar, NEUTRAL_DIR); | |
89d3374a EZ |
999 | bidi_it->orig_type = type; |
1000 | bidi_check_type (bidi_it->orig_type); | |
b7b65b15 EZ |
1001 | |
1002 | if (type != PDF) | |
1003 | bidi_it->prev_was_pdf = 0; | |
1004 | ||
89d3374a | 1005 | bidi_it->type_after_w1 = UNKNOWN_BT; |
b7b65b15 EZ |
1006 | |
1007 | switch (type) | |
1008 | { | |
1009 | case RLE: /* X2 */ | |
1010 | case RLO: /* X4 */ | |
89d3374a EZ |
1011 | bidi_it->type_after_w1 = type; |
1012 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 EZ |
1013 | type = WEAK_BN; /* X9/Retaining */ |
1014 | if (bidi_it->ignore_bn_limit <= 0) | |
1015 | { | |
1016 | if (current_level <= BIDI_MAXLEVEL - 4) | |
1017 | { | |
1018 | /* Compute the least odd embedding level greater than | |
1019 | the current level. */ | |
1020 | new_level = ((current_level + 1) & ~1) + 1; | |
89d3374a | 1021 | if (bidi_it->type_after_w1 == RLE) |
b7b65b15 EZ |
1022 | override = NEUTRAL_DIR; |
1023 | else | |
1024 | override = R2L; | |
1025 | if (current_level == BIDI_MAXLEVEL - 4) | |
1026 | bidi_it->invalid_rl_levels = 0; | |
1027 | bidi_push_embedding_level (bidi_it, new_level, override); | |
1028 | } | |
1029 | else | |
1030 | { | |
1031 | bidi_it->invalid_levels++; | |
1032 | /* See the commentary about invalid_rl_levels below. */ | |
1033 | if (bidi_it->invalid_rl_levels < 0) | |
1034 | bidi_it->invalid_rl_levels = 0; | |
1035 | bidi_it->invalid_rl_levels++; | |
1036 | } | |
1037 | } | |
89d3374a | 1038 | else if (bidi_it->prev.type_after_w1 == WEAK_EN /* W5/Retaining */ |
b7b65b15 EZ |
1039 | || bidi_it->next_en_pos > bidi_it->charpos) |
1040 | type = WEAK_EN; | |
1041 | break; | |
1042 | case LRE: /* X3 */ | |
1043 | case LRO: /* X5 */ | |
89d3374a EZ |
1044 | bidi_it->type_after_w1 = type; |
1045 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 EZ |
1046 | type = WEAK_BN; /* X9/Retaining */ |
1047 | if (bidi_it->ignore_bn_limit <= 0) | |
1048 | { | |
1049 | if (current_level <= BIDI_MAXLEVEL - 5) | |
1050 | { | |
1051 | /* Compute the least even embedding level greater than | |
1052 | the current level. */ | |
1053 | new_level = ((current_level + 2) & ~1); | |
89d3374a | 1054 | if (bidi_it->type_after_w1 == LRE) |
b7b65b15 EZ |
1055 | override = NEUTRAL_DIR; |
1056 | else | |
1057 | override = L2R; | |
1058 | bidi_push_embedding_level (bidi_it, new_level, override); | |
1059 | } | |
1060 | else | |
1061 | { | |
1062 | bidi_it->invalid_levels++; | |
1063 | /* invalid_rl_levels counts invalid levels encountered | |
1064 | while the embedding level was already too high for | |
1065 | LRE/LRO, but not for RLE/RLO. That is because | |
1066 | there may be exactly one PDF which we should not | |
1067 | ignore even though invalid_levels is non-zero. | |
1068 | invalid_rl_levels helps to know what PDF is | |
1069 | that. */ | |
1070 | if (bidi_it->invalid_rl_levels >= 0) | |
1071 | bidi_it->invalid_rl_levels++; | |
1072 | } | |
1073 | } | |
89d3374a | 1074 | else if (bidi_it->prev.type_after_w1 == WEAK_EN /* W5/Retaining */ |
b7b65b15 EZ |
1075 | || bidi_it->next_en_pos > bidi_it->charpos) |
1076 | type = WEAK_EN; | |
1077 | break; | |
1078 | case PDF: /* X7 */ | |
89d3374a EZ |
1079 | bidi_it->type_after_w1 = type; |
1080 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 EZ |
1081 | type = WEAK_BN; /* X9/Retaining */ |
1082 | if (bidi_it->ignore_bn_limit <= 0) | |
1083 | { | |
1084 | if (!bidi_it->invalid_rl_levels) | |
1085 | { | |
1086 | new_level = bidi_pop_embedding_level (bidi_it); | |
1087 | bidi_it->invalid_rl_levels = -1; | |
1088 | if (bidi_it->invalid_levels) | |
1089 | bidi_it->invalid_levels--; | |
1090 | /* else nothing: UAX#9 says to ignore invalid PDFs */ | |
1091 | } | |
1092 | if (!bidi_it->invalid_levels) | |
1093 | new_level = bidi_pop_embedding_level (bidi_it); | |
1094 | else | |
1095 | { | |
1096 | bidi_it->invalid_levels--; | |
1097 | bidi_it->invalid_rl_levels--; | |
1098 | } | |
1099 | } | |
89d3374a | 1100 | else if (bidi_it->prev.type_after_w1 == WEAK_EN /* W5/Retaining */ |
b7b65b15 EZ |
1101 | || bidi_it->next_en_pos > bidi_it->charpos) |
1102 | type = WEAK_EN; | |
1103 | break; | |
1104 | default: | |
1105 | /* Nothing. */ | |
1106 | break; | |
1107 | } | |
1108 | ||
1109 | bidi_it->type = type; | |
2d6e4628 | 1110 | bidi_check_type (bidi_it->type); |
b7b65b15 EZ |
1111 | |
1112 | return new_level; | |
1113 | } | |
1114 | ||
1115 | /* Given an iterator state in BIDI_IT, advance one character position | |
182ce2d2 EZ |
1116 | in the buffer/string to the next character (in the logical order), |
1117 | resolve any explicit embeddings and directional overrides, and | |
1118 | return the embedding level of the character after resolving | |
1119 | explicit directives and ignoring empty embeddings. */ | |
b7b65b15 EZ |
1120 | static int |
1121 | bidi_resolve_explicit (struct bidi_it *bidi_it) | |
1122 | { | |
1123 | int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level; | |
1124 | int new_level = bidi_resolve_explicit_1 (bidi_it); | |
1125 | ||
1126 | if (prev_level < new_level | |
1127 | && bidi_it->type == WEAK_BN | |
1128 | && bidi_it->ignore_bn_limit == 0 /* only if not already known */ | |
1502b819 | 1129 | && bidi_it->bytepos < ZV_BYTE /* not already at EOB */ |
182ce2d2 EZ |
1130 | && bidi_explicit_dir_char (FETCH_MULTIBYTE_CHAR (bidi_it->bytepos |
1131 | + bidi_it->ch_len))) | |
b7b65b15 EZ |
1132 | { |
1133 | /* Avoid pushing and popping embedding levels if the level run | |
1134 | is empty, as this breaks level runs where it shouldn't. | |
1135 | UAX#9 removes all the explicit embedding and override codes, | |
1136 | so empty embeddings disappear without a trace. We need to | |
1137 | behave as if we did the same. */ | |
1138 | struct bidi_it saved_it; | |
1139 | int level = prev_level; | |
1140 | ||
1141 | bidi_copy_it (&saved_it, bidi_it); | |
1142 | ||
182ce2d2 EZ |
1143 | while (bidi_explicit_dir_char (FETCH_MULTIBYTE_CHAR (bidi_it->bytepos |
1144 | + bidi_it->ch_len))) | |
b7b65b15 | 1145 | { |
182ce2d2 EZ |
1146 | /* This advances to the next character, skipping any |
1147 | characters covered by display strings. */ | |
b7b65b15 EZ |
1148 | level = bidi_resolve_explicit_1 (bidi_it); |
1149 | } | |
1150 | ||
102ebb00 EZ |
1151 | if (bidi_it->nchars <= 0) |
1152 | abort (); | |
b7b65b15 | 1153 | if (level == prev_level) /* empty embedding */ |
182ce2d2 | 1154 | saved_it.ignore_bn_limit = bidi_it->charpos + bidi_it->nchars; |
b7b65b15 EZ |
1155 | else /* this embedding is non-empty */ |
1156 | saved_it.ignore_bn_limit = -1; | |
1157 | ||
1158 | bidi_copy_it (bidi_it, &saved_it); | |
1159 | if (bidi_it->ignore_bn_limit > 0) | |
1160 | { | |
1161 | /* We pushed a level, but we shouldn't have. Undo that. */ | |
1162 | if (!bidi_it->invalid_rl_levels) | |
1163 | { | |
1164 | new_level = bidi_pop_embedding_level (bidi_it); | |
1165 | bidi_it->invalid_rl_levels = -1; | |
1166 | if (bidi_it->invalid_levels) | |
1167 | bidi_it->invalid_levels--; | |
1168 | } | |
1169 | if (!bidi_it->invalid_levels) | |
1170 | new_level = bidi_pop_embedding_level (bidi_it); | |
1171 | else | |
1172 | { | |
1173 | bidi_it->invalid_levels--; | |
1174 | bidi_it->invalid_rl_levels--; | |
1175 | } | |
1176 | } | |
1177 | } | |
1178 | ||
b7b65b15 EZ |
1179 | if (bidi_it->type == NEUTRAL_B) /* X8 */ |
1180 | { | |
21fce5ab | 1181 | bidi_set_paragraph_end (bidi_it); |
6bff6497 EZ |
1182 | /* This is needed by bidi_resolve_weak below, and in L1. */ |
1183 | bidi_it->type_after_w1 = bidi_it->type; | |
89d3374a | 1184 | bidi_check_type (bidi_it->type_after_w1); |
b7b65b15 EZ |
1185 | } |
1186 | ||
1187 | return new_level; | |
1188 | } | |
1189 | ||
182ce2d2 EZ |
1190 | /* Advance in the buffer/string, resolve weak types and return the |
1191 | type of the next character after weak type resolution. */ | |
fd3998ff | 1192 | static bidi_type_t |
b7b65b15 EZ |
1193 | bidi_resolve_weak (struct bidi_it *bidi_it) |
1194 | { | |
1195 | bidi_type_t type; | |
1196 | bidi_dir_t override; | |
1197 | int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level; | |
1198 | int new_level = bidi_resolve_explicit (bidi_it); | |
1199 | int next_char; | |
1200 | bidi_type_t type_of_next; | |
1201 | struct bidi_it saved_it; | |
1202 | ||
1203 | type = bidi_it->type; | |
1204 | override = bidi_it->level_stack[bidi_it->stack_idx].override; | |
1205 | ||
1206 | if (type == UNKNOWN_BT | |
1207 | || type == LRE | |
1208 | || type == LRO | |
1209 | || type == RLE | |
1210 | || type == RLO | |
1211 | || type == PDF) | |
1212 | abort (); | |
1213 | ||
1214 | if (new_level != prev_level | |
1215 | || bidi_it->type == NEUTRAL_B) | |
1216 | { | |
1217 | /* We've got a new embedding level run, compute the directional | |
1218 | type of sor and initialize per-run variables (UAX#9, clause | |
1219 | X10). */ | |
1220 | bidi_set_sor_type (bidi_it, prev_level, new_level); | |
1221 | } | |
1222 | else if (type == NEUTRAL_S || type == NEUTRAL_WS | |
1223 | || type == WEAK_BN || type == STRONG_AL) | |
89d3374a EZ |
1224 | bidi_it->type_after_w1 = type; /* needed in L1 */ |
1225 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 EZ |
1226 | |
1227 | /* Level and directional override status are already recorded in | |
1228 | bidi_it, and do not need any change; see X6. */ | |
1229 | if (override == R2L) /* X6 */ | |
1230 | type = STRONG_R; | |
1231 | else if (override == L2R) | |
1232 | type = STRONG_L; | |
bc5a45f3 | 1233 | else |
b7b65b15 | 1234 | { |
bc5a45f3 | 1235 | if (type == WEAK_NSM) /* W1 */ |
b7b65b15 | 1236 | { |
bc5a45f3 | 1237 | /* Note that we don't need to consider the case where the |
5930fe97 EZ |
1238 | prev character has its type overridden by an RLO or LRO, |
1239 | because then either the type of this NSM would have been | |
1240 | also overridden, or the previous character is outside the | |
1241 | current level run, and thus not relevant to this NSM. | |
1242 | This is why NSM gets the type_after_w1 of the previous | |
1243 | character. */ | |
ebb5722e EZ |
1244 | if (bidi_it->prev.type_after_w1 != UNKNOWN_BT |
1245 | /* if type_after_w1 is NEUTRAL_B, this NSM is at sor */ | |
1246 | && bidi_it->prev.type_after_w1 != NEUTRAL_B) | |
5930fe97 | 1247 | type = bidi_it->prev.type_after_w1; |
bc5a45f3 EZ |
1248 | else if (bidi_it->sor == R2L) |
1249 | type = STRONG_R; | |
1250 | else if (bidi_it->sor == L2R) | |
1251 | type = STRONG_L; | |
1252 | else /* shouldn't happen! */ | |
1253 | abort (); | |
b7b65b15 | 1254 | } |
bc5a45f3 EZ |
1255 | if (type == WEAK_EN /* W2 */ |
1256 | && bidi_it->last_strong.type_after_w1 == STRONG_AL) | |
1257 | type = WEAK_AN; | |
1258 | else if (type == STRONG_AL) /* W3 */ | |
1259 | type = STRONG_R; | |
1260 | else if ((type == WEAK_ES /* W4 */ | |
1261 | && bidi_it->prev.type_after_w1 == WEAK_EN | |
1262 | && bidi_it->prev.orig_type == WEAK_EN) | |
1263 | || (type == WEAK_CS | |
1264 | && ((bidi_it->prev.type_after_w1 == WEAK_EN | |
1265 | && bidi_it->prev.orig_type == WEAK_EN) | |
1266 | || bidi_it->prev.type_after_w1 == WEAK_AN))) | |
b7b65b15 | 1267 | { |
e7402cb2 EZ |
1268 | next_char = |
1269 | bidi_it->bytepos + bidi_it->ch_len >= ZV_BYTE | |
182ce2d2 EZ |
1270 | ? BIDI_EOB : FETCH_MULTIBYTE_CHAR (bidi_it->bytepos |
1271 | + bidi_it->ch_len); | |
6bff6497 | 1272 | type_of_next = bidi_get_type (next_char, override); |
b7b65b15 | 1273 | |
bc5a45f3 | 1274 | if (type_of_next == WEAK_BN |
b7b65b15 EZ |
1275 | || bidi_explicit_dir_char (next_char)) |
1276 | { | |
1277 | bidi_copy_it (&saved_it, bidi_it); | |
1278 | while (bidi_resolve_explicit (bidi_it) == new_level | |
bc5a45f3 | 1279 | && bidi_it->type == WEAK_BN) |
b7b65b15 EZ |
1280 | ; |
1281 | type_of_next = bidi_it->type; | |
b7b65b15 EZ |
1282 | bidi_copy_it (bidi_it, &saved_it); |
1283 | } | |
bc5a45f3 EZ |
1284 | |
1285 | /* If the next character is EN, but the last strong-type | |
1286 | character is AL, that next EN will be changed to AN when | |
1287 | we process it in W2 above. So in that case, this ES | |
1288 | should not be changed into EN. */ | |
1289 | if (type == WEAK_ES | |
1290 | && type_of_next == WEAK_EN | |
1291 | && bidi_it->last_strong.type_after_w1 != STRONG_AL) | |
1292 | type = WEAK_EN; | |
1293 | else if (type == WEAK_CS) | |
b7b65b15 | 1294 | { |
bc5a45f3 EZ |
1295 | if (bidi_it->prev.type_after_w1 == WEAK_AN |
1296 | && (type_of_next == WEAK_AN | |
1297 | /* If the next character is EN, but the last | |
1298 | strong-type character is AL, EN will be later | |
1299 | changed to AN when we process it in W2 above. | |
1300 | So in that case, this ES should not be | |
1301 | changed into EN. */ | |
1302 | || (type_of_next == WEAK_EN | |
1303 | && bidi_it->last_strong.type_after_w1 == STRONG_AL))) | |
1304 | type = WEAK_AN; | |
1305 | else if (bidi_it->prev.type_after_w1 == WEAK_EN | |
1306 | && type_of_next == WEAK_EN | |
1307 | && bidi_it->last_strong.type_after_w1 != STRONG_AL) | |
1308 | type = WEAK_EN; | |
1309 | } | |
1310 | } | |
1311 | else if (type == WEAK_ET /* W5: ET with EN before or after it */ | |
1312 | || type == WEAK_BN) /* W5/Retaining */ | |
1313 | { | |
1314 | if (bidi_it->prev.type_after_w1 == WEAK_EN /* ET/BN w/EN before it */ | |
1315 | || bidi_it->next_en_pos > bidi_it->charpos) | |
1316 | type = WEAK_EN; | |
1317 | else /* W5: ET/BN with EN after it. */ | |
1318 | { | |
182ce2d2 | 1319 | EMACS_INT en_pos = bidi_it->charpos + bidi_it->nchars; |
bc5a45f3 | 1320 | |
102ebb00 EZ |
1321 | if (bidi_it->nchars <= 0) |
1322 | abort (); | |
bc5a45f3 EZ |
1323 | next_char = |
1324 | bidi_it->bytepos + bidi_it->ch_len >= ZV_BYTE | |
182ce2d2 EZ |
1325 | ? BIDI_EOB : FETCH_MULTIBYTE_CHAR (bidi_it->bytepos |
1326 | + bidi_it->ch_len); | |
bc5a45f3 EZ |
1327 | type_of_next = bidi_get_type (next_char, override); |
1328 | ||
1329 | if (type_of_next == WEAK_ET | |
1330 | || type_of_next == WEAK_BN | |
1331 | || bidi_explicit_dir_char (next_char)) | |
1332 | { | |
1333 | bidi_copy_it (&saved_it, bidi_it); | |
1334 | while (bidi_resolve_explicit (bidi_it) == new_level | |
1335 | && (bidi_it->type == WEAK_BN | |
1336 | || bidi_it->type == WEAK_ET)) | |
1337 | ; | |
1338 | type_of_next = bidi_it->type; | |
1339 | en_pos = bidi_it->charpos; | |
1340 | bidi_copy_it (bidi_it, &saved_it); | |
1341 | } | |
1342 | if (type_of_next == WEAK_EN) | |
b7b65b15 | 1343 | { |
bc5a45f3 EZ |
1344 | /* If the last strong character is AL, the EN we've |
1345 | found will become AN when we get to it (W2). */ | |
1346 | if (bidi_it->last_strong.type_after_w1 != STRONG_AL) | |
1347 | { | |
1348 | type = WEAK_EN; | |
1349 | /* Remember this EN position, to speed up processing | |
1350 | of the next ETs. */ | |
1351 | bidi_it->next_en_pos = en_pos; | |
1352 | } | |
1353 | else if (type == WEAK_BN) | |
1354 | type = NEUTRAL_ON; /* W6/Retaining */ | |
b7b65b15 | 1355 | } |
b7b65b15 EZ |
1356 | } |
1357 | } | |
1358 | } | |
1359 | ||
1360 | if (type == WEAK_ES || type == WEAK_ET || type == WEAK_CS /* W6 */ | |
89d3374a EZ |
1361 | || (type == WEAK_BN |
1362 | && (bidi_it->prev.type_after_w1 == WEAK_CS /* W6/Retaining */ | |
1363 | || bidi_it->prev.type_after_w1 == WEAK_ES | |
1364 | || bidi_it->prev.type_after_w1 == WEAK_ET))) | |
b7b65b15 EZ |
1365 | type = NEUTRAL_ON; |
1366 | ||
1367 | /* Store the type we've got so far, before we clobber it with strong | |
1368 | types in W7 and while resolving neutral types. But leave alone | |
1369 | the original types that were recorded above, because we will need | |
1370 | them for the L1 clause. */ | |
89d3374a EZ |
1371 | if (bidi_it->type_after_w1 == UNKNOWN_BT) |
1372 | bidi_it->type_after_w1 = type; | |
1373 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 EZ |
1374 | |
1375 | if (type == WEAK_EN) /* W7 */ | |
1376 | { | |
89d3374a | 1377 | if ((bidi_it->last_strong.type_after_w1 == STRONG_L) |
b7b65b15 EZ |
1378 | || (bidi_it->last_strong.type == UNKNOWN_BT && bidi_it->sor == L2R)) |
1379 | type = STRONG_L; | |
1380 | } | |
1381 | ||
1382 | bidi_it->type = type; | |
2d6e4628 | 1383 | bidi_check_type (bidi_it->type); |
b7b65b15 EZ |
1384 | return type; |
1385 | } | |
1386 | ||
fd3998ff | 1387 | static bidi_type_t |
b7b65b15 EZ |
1388 | bidi_resolve_neutral (struct bidi_it *bidi_it) |
1389 | { | |
1390 | int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level; | |
1391 | bidi_type_t type = bidi_resolve_weak (bidi_it); | |
1392 | int current_level = bidi_it->level_stack[bidi_it->stack_idx].level; | |
1393 | ||
1394 | if (!(type == STRONG_R | |
1395 | || type == STRONG_L | |
1396 | || type == WEAK_BN | |
1397 | || type == WEAK_EN | |
1398 | || type == WEAK_AN | |
1399 | || type == NEUTRAL_B | |
1400 | || type == NEUTRAL_S | |
1401 | || type == NEUTRAL_WS | |
1402 | || type == NEUTRAL_ON)) | |
1403 | abort (); | |
1404 | ||
1405 | if (bidi_get_category (type) == NEUTRAL | |
1406 | || (type == WEAK_BN && prev_level == current_level)) | |
1407 | { | |
1408 | if (bidi_it->next_for_neutral.type != UNKNOWN_BT) | |
1409 | type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type, | |
1410 | bidi_it->next_for_neutral.type, | |
1411 | current_level); | |
1412 | else | |
1413 | { | |
1414 | /* Arrrgh!! The UAX#9 algorithm is too deeply entrenched in | |
1415 | the assumption of batch-style processing; see clauses W4, | |
1416 | W5, and especially N1, which require to look far forward | |
182ce2d2 EZ |
1417 | (as well as back) in the buffer/string. May the fleas of |
1418 | a thousand camels infest the armpits of those who design | |
b7b65b15 EZ |
1419 | supposedly general-purpose algorithms by looking at their |
1420 | own implementations, and fail to consider other possible | |
1421 | implementations! */ | |
1422 | struct bidi_it saved_it; | |
1423 | bidi_type_t next_type; | |
1424 | ||
1425 | if (bidi_it->scan_dir == -1) | |
1426 | abort (); | |
1427 | ||
1428 | bidi_copy_it (&saved_it, bidi_it); | |
1429 | /* Scan the text forward until we find the first non-neutral | |
1430 | character, and then use that to resolve the neutral we | |
1431 | are dealing with now. We also cache the scanned iterator | |
1432 | states, to salvage some of the effort later. */ | |
1433 | bidi_cache_iterator_state (bidi_it, 0); | |
1434 | do { | |
1435 | /* Record the info about the previous character, so that | |
1436 | it will be cached below with this state. */ | |
89d3374a | 1437 | if (bidi_it->type_after_w1 != WEAK_BN /* W1/Retaining */ |
b7b65b15 EZ |
1438 | && bidi_it->type != WEAK_BN) |
1439 | bidi_remember_char (&bidi_it->prev, bidi_it); | |
1440 | type = bidi_resolve_weak (bidi_it); | |
1441 | /* Paragraph separators have their levels fully resolved | |
1442 | at this point, so cache them as resolved. */ | |
1443 | bidi_cache_iterator_state (bidi_it, type == NEUTRAL_B); | |
1444 | /* FIXME: implement L1 here, by testing for a newline and | |
1445 | resetting the level for any sequence of whitespace | |
1446 | characters adjacent to it. */ | |
1447 | } while (!(type == NEUTRAL_B | |
1448 | || (type != WEAK_BN | |
1449 | && bidi_get_category (type) != NEUTRAL) | |
1450 | /* This is all per level run, so stop when we | |
1451 | reach the end of this level run. */ | |
1452 | || bidi_it->level_stack[bidi_it->stack_idx].level != | |
1453 | current_level)); | |
1454 | ||
1455 | bidi_remember_char (&saved_it.next_for_neutral, bidi_it); | |
1456 | ||
1457 | switch (type) | |
1458 | { | |
1459 | case STRONG_L: | |
1460 | case STRONG_R: | |
1461 | case STRONG_AL: | |
1462 | next_type = type; | |
1463 | break; | |
1464 | case WEAK_EN: | |
1465 | case WEAK_AN: | |
1466 | /* N1: ``European and Arabic numbers are treated as | |
1467 | though they were R.'' */ | |
1468 | next_type = STRONG_R; | |
1469 | saved_it.next_for_neutral.type = STRONG_R; | |
1470 | break; | |
1471 | case WEAK_BN: | |
1472 | if (!bidi_explicit_dir_char (bidi_it->ch)) | |
1473 | abort (); /* can't happen: BNs are skipped */ | |
1474 | /* FALLTHROUGH */ | |
1475 | case NEUTRAL_B: | |
1476 | /* Marched all the way to the end of this level run. | |
1477 | We need to use the eor type, whose information is | |
1478 | stored by bidi_set_sor_type in the prev_for_neutral | |
1479 | member. */ | |
1480 | if (saved_it.type != WEAK_BN | |
89d3374a | 1481 | || bidi_get_category (bidi_it->prev.type_after_w1) == NEUTRAL) |
b7b65b15 EZ |
1482 | { |
1483 | next_type = bidi_it->prev_for_neutral.type; | |
1484 | saved_it.next_for_neutral.type = next_type; | |
2d6e4628 | 1485 | bidi_check_type (next_type); |
b7b65b15 EZ |
1486 | } |
1487 | else | |
1488 | { | |
1489 | /* This is a BN which does not adjoin neutrals. | |
1490 | Leave its type alone. */ | |
1491 | bidi_copy_it (bidi_it, &saved_it); | |
1492 | return bidi_it->type; | |
1493 | } | |
1494 | break; | |
1495 | default: | |
1496 | abort (); | |
1497 | } | |
1498 | type = bidi_resolve_neutral_1 (saved_it.prev_for_neutral.type, | |
1499 | next_type, current_level); | |
1500 | saved_it.type = type; | |
2d6e4628 | 1501 | bidi_check_type (type); |
b7b65b15 EZ |
1502 | bidi_copy_it (bidi_it, &saved_it); |
1503 | } | |
1504 | } | |
1505 | return type; | |
1506 | } | |
1507 | ||
1508 | /* Given an iterator state in BIDI_IT, advance one character position | |
182ce2d2 EZ |
1509 | in the buffer/string to the next character (in the logical order), |
1510 | resolve the bidi type of that next character, and return that | |
1511 | type. */ | |
fd3998ff | 1512 | static bidi_type_t |
b7b65b15 EZ |
1513 | bidi_type_of_next_char (struct bidi_it *bidi_it) |
1514 | { | |
1515 | bidi_type_t type; | |
1516 | ||
1517 | /* This should always be called during a forward scan. */ | |
1518 | if (bidi_it->scan_dir != 1) | |
1519 | abort (); | |
1520 | ||
1521 | /* Reset the limit until which to ignore BNs if we step out of the | |
1522 | area where we found only empty levels. */ | |
1523 | if ((bidi_it->ignore_bn_limit > 0 | |
1524 | && bidi_it->ignore_bn_limit <= bidi_it->charpos) | |
1525 | || (bidi_it->ignore_bn_limit == -1 | |
1526 | && !bidi_explicit_dir_char (bidi_it->ch))) | |
1527 | bidi_it->ignore_bn_limit = 0; | |
1528 | ||
1529 | type = bidi_resolve_neutral (bidi_it); | |
1530 | ||
1531 | return type; | |
1532 | } | |
1533 | ||
1534 | /* Given an iterator state BIDI_IT, advance one character position in | |
182ce2d2 EZ |
1535 | the buffer/string to the next character (in the current scan |
1536 | direction), resolve the embedding and implicit levels of that next | |
1537 | character, and return the resulting level. */ | |
fd3998ff | 1538 | static int |
b7b65b15 EZ |
1539 | bidi_level_of_next_char (struct bidi_it *bidi_it) |
1540 | { | |
1541 | bidi_type_t type; | |
1542 | int level, prev_level = -1; | |
1543 | struct bidi_saved_info next_for_neutral; | |
182ce2d2 | 1544 | EMACS_INT next_char_pos; |
b7b65b15 EZ |
1545 | |
1546 | if (bidi_it->scan_dir == 1) | |
1547 | { | |
1548 | /* There's no sense in trying to advance if we hit end of text. */ | |
1502b819 | 1549 | if (bidi_it->bytepos >= ZV_BYTE) |
b7b65b15 EZ |
1550 | return bidi_it->resolved_level; |
1551 | ||
1552 | /* Record the info about the previous character. */ | |
89d3374a | 1553 | if (bidi_it->type_after_w1 != WEAK_BN /* W1/Retaining */ |
b7b65b15 EZ |
1554 | && bidi_it->type != WEAK_BN) |
1555 | bidi_remember_char (&bidi_it->prev, bidi_it); | |
89d3374a EZ |
1556 | if (bidi_it->type_after_w1 == STRONG_R |
1557 | || bidi_it->type_after_w1 == STRONG_L | |
1558 | || bidi_it->type_after_w1 == STRONG_AL) | |
b7b65b15 EZ |
1559 | bidi_remember_char (&bidi_it->last_strong, bidi_it); |
1560 | /* FIXME: it sounds like we don't need both prev and | |
1561 | prev_for_neutral members, but I'm leaving them both for now. */ | |
1562 | if (bidi_it->type == STRONG_R || bidi_it->type == STRONG_L | |
1563 | || bidi_it->type == WEAK_EN || bidi_it->type == WEAK_AN) | |
1564 | bidi_remember_char (&bidi_it->prev_for_neutral, bidi_it); | |
1565 | ||
1566 | /* If we overstepped the characters used for resolving neutrals | |
1567 | and whitespace, invalidate their info in the iterator. */ | |
1568 | if (bidi_it->charpos >= bidi_it->next_for_neutral.charpos) | |
1569 | bidi_it->next_for_neutral.type = UNKNOWN_BT; | |
1570 | if (bidi_it->next_en_pos >= 0 | |
1571 | && bidi_it->charpos >= bidi_it->next_en_pos) | |
1572 | bidi_it->next_en_pos = -1; | |
1573 | if (bidi_it->next_for_ws.type != UNKNOWN_BT | |
1574 | && bidi_it->charpos >= bidi_it->next_for_ws.charpos) | |
1575 | bidi_it->next_for_ws.type = UNKNOWN_BT; | |
1576 | ||
1577 | /* This must be taken before we fill the iterator with the info | |
1578 | about the next char. If we scan backwards, the iterator | |
1579 | state must be already cached, so there's no need to know the | |
1580 | embedding level of the previous character, since we will be | |
1581 | returning to our caller shortly. */ | |
1582 | prev_level = bidi_it->level_stack[bidi_it->stack_idx].level; | |
1583 | } | |
1584 | next_for_neutral = bidi_it->next_for_neutral; | |
1585 | ||
182ce2d2 EZ |
1586 | /* Perhaps the character we want is already cached. If it is, the |
1587 | call to bidi_cache_find below will return a type other than | |
1588 | UNKNOWN_BT. */ | |
102ebb00 EZ |
1589 | if (bidi_cache_idx && !bidi_it->first_elt) |
1590 | { | |
1591 | if (bidi_it->scan_dir > 0) | |
1592 | { | |
1593 | if (bidi_it->nchars <= 0) | |
1594 | abort (); | |
1595 | next_char_pos = bidi_it->charpos + bidi_it->nchars; | |
1596 | } | |
1597 | else | |
1598 | next_char_pos = bidi_it->charpos - 1; | |
1599 | type = bidi_cache_find (next_char_pos, -1, bidi_it); | |
1600 | } | |
182ce2d2 | 1601 | else |
102ebb00 | 1602 | type = UNKNOWN_BT; |
b7b65b15 EZ |
1603 | if (type != UNKNOWN_BT) |
1604 | { | |
1605 | /* Don't lose the information for resolving neutrals! The | |
1606 | cached states could have been cached before their | |
1607 | next_for_neutral member was computed. If we are on our way | |
1608 | forward, we can simply take the info from the previous | |
1609 | state. */ | |
1610 | if (bidi_it->scan_dir == 1 | |
1611 | && bidi_it->next_for_neutral.type == UNKNOWN_BT) | |
1612 | bidi_it->next_for_neutral = next_for_neutral; | |
1613 | ||
1614 | /* If resolved_level is -1, it means this state was cached | |
1615 | before it was completely resolved, so we cannot return | |
1616 | it. */ | |
1617 | if (bidi_it->resolved_level != -1) | |
1618 | return bidi_it->resolved_level; | |
1619 | } | |
1620 | if (bidi_it->scan_dir == -1) | |
1621 | /* If we are going backwards, the iterator state is already cached | |
1622 | from previous scans, and should be fully resolved. */ | |
1623 | abort (); | |
1624 | ||
1625 | if (type == UNKNOWN_BT) | |
1626 | type = bidi_type_of_next_char (bidi_it); | |
1627 | ||
1628 | if (type == NEUTRAL_B) | |
1629 | return bidi_it->resolved_level; | |
1630 | ||
1631 | level = bidi_it->level_stack[bidi_it->stack_idx].level; | |
1632 | if ((bidi_get_category (type) == NEUTRAL /* && type != NEUTRAL_B */) | |
1633 | || (type == WEAK_BN && prev_level == level)) | |
1634 | { | |
1635 | if (bidi_it->next_for_neutral.type == UNKNOWN_BT) | |
1636 | abort (); | |
1637 | ||
1638 | /* If the cached state shows a neutral character, it was not | |
1639 | resolved by bidi_resolve_neutral, so do it now. */ | |
1640 | type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type, | |
1641 | bidi_it->next_for_neutral.type, | |
1642 | level); | |
1643 | } | |
1644 | ||
1645 | if (!(type == STRONG_R | |
1646 | || type == STRONG_L | |
1647 | || type == WEAK_BN | |
1648 | || type == WEAK_EN | |
1649 | || type == WEAK_AN)) | |
1650 | abort (); | |
1651 | bidi_it->type = type; | |
2d6e4628 | 1652 | bidi_check_type (bidi_it->type); |
b7b65b15 EZ |
1653 | |
1654 | /* For L1 below, we need to know, for each WS character, whether | |
0d327994 | 1655 | it belongs to a sequence of WS characters preceding a newline |
b7b65b15 | 1656 | or a TAB or a paragraph separator. */ |
89d3374a | 1657 | if (bidi_it->orig_type == NEUTRAL_WS |
b7b65b15 EZ |
1658 | && bidi_it->next_for_ws.type == UNKNOWN_BT) |
1659 | { | |
1660 | int ch; | |
1661 | int clen = bidi_it->ch_len; | |
6bff6497 EZ |
1662 | EMACS_INT bpos = bidi_it->bytepos; |
1663 | EMACS_INT cpos = bidi_it->charpos; | |
182ce2d2 | 1664 | EMACS_INT disp_pos = bidi_it->disp_pos; |
102ebb00 | 1665 | EMACS_INT nc = bidi_it->nchars; |
b7b65b15 EZ |
1666 | bidi_type_t chtype; |
1667 | ||
102ebb00 EZ |
1668 | if (bidi_it->nchars <= 0) |
1669 | abort (); | |
b7b65b15 | 1670 | do { |
102ebb00 | 1671 | ch = bidi_fetch_char (bpos += clen, cpos += nc, &disp_pos, &clen, &nc); |
e7402cb2 | 1672 | if (ch == '\n' || ch == BIDI_EOB /* || ch == LINESEP_CHAR */) |
b7b65b15 EZ |
1673 | chtype = NEUTRAL_B; |
1674 | else | |
6bff6497 | 1675 | chtype = bidi_get_type (ch, NEUTRAL_DIR); |
b7b65b15 EZ |
1676 | } while (chtype == NEUTRAL_WS || chtype == WEAK_BN |
1677 | || bidi_explicit_dir_char (ch)); /* L1/Retaining */ | |
1678 | bidi_it->next_for_ws.type = chtype; | |
2d6e4628 | 1679 | bidi_check_type (bidi_it->next_for_ws.type); |
b7b65b15 EZ |
1680 | bidi_it->next_for_ws.charpos = cpos; |
1681 | bidi_it->next_for_ws.bytepos = bpos; | |
1682 | } | |
1683 | ||
1684 | /* Resolve implicit levels, with a twist: PDFs get the embedding | |
1685 | level of the enbedding they terminate. See below for the | |
1686 | reason. */ | |
89d3374a | 1687 | if (bidi_it->orig_type == PDF |
b7b65b15 EZ |
1688 | /* Don't do this if this formatting code didn't change the |
1689 | embedding level due to invalid or empty embeddings. */ | |
1690 | && prev_level != level) | |
1691 | { | |
1692 | /* Don't look in UAX#9 for the reason for this: it's our own | |
1693 | private quirk. The reason is that we want the formatting | |
1694 | codes to be delivered so that they bracket the text of their | |
1695 | embedding. For example, given the text | |
1696 | ||
1697 | {RLO}teST{PDF} | |
1698 | ||
1699 | we want it to be displayed as | |
1700 | ||
0d68907d | 1701 | {PDF}STet{RLO} |
b7b65b15 EZ |
1702 | |
1703 | not as | |
1704 | ||
1705 | STet{RLO}{PDF} | |
1706 | ||
1707 | which will result because we bump up the embedding level as | |
1708 | soon as we see the RLO and pop it as soon as we see the PDF, | |
1709 | so RLO itself has the same embedding level as "teST", and | |
1710 | thus would be normally delivered last, just before the PDF. | |
1711 | The switch below fiddles with the level of PDF so that this | |
1712 | ugly side effect does not happen. | |
1713 | ||
1714 | (This is, of course, only important if the formatting codes | |
e7402cb2 EZ |
1715 | are actually displayed, but Emacs does need to display them |
1716 | if the user wants to.) */ | |
b7b65b15 EZ |
1717 | level = prev_level; |
1718 | } | |
89d3374a EZ |
1719 | else if (bidi_it->orig_type == NEUTRAL_B /* L1 */ |
1720 | || bidi_it->orig_type == NEUTRAL_S | |
e7402cb2 EZ |
1721 | || bidi_it->ch == '\n' || bidi_it->ch == BIDI_EOB |
1722 | /* || bidi_it->ch == LINESEP_CHAR */ | |
89d3374a | 1723 | || (bidi_it->orig_type == NEUTRAL_WS |
b7b65b15 EZ |
1724 | && (bidi_it->next_for_ws.type == NEUTRAL_B |
1725 | || bidi_it->next_for_ws.type == NEUTRAL_S))) | |
1726 | level = bidi_it->level_stack[0].level; | |
1727 | else if ((level & 1) == 0) /* I1 */ | |
1728 | { | |
1729 | if (type == STRONG_R) | |
1730 | level++; | |
1731 | else if (type == WEAK_EN || type == WEAK_AN) | |
1732 | level += 2; | |
1733 | } | |
1734 | else /* I2 */ | |
1735 | { | |
1736 | if (type == STRONG_L || type == WEAK_EN || type == WEAK_AN) | |
1737 | level++; | |
1738 | } | |
1739 | ||
1740 | bidi_it->resolved_level = level; | |
1741 | return level; | |
1742 | } | |
1743 | ||
1744 | /* Move to the other edge of a level given by LEVEL. If END_FLAG is | |
1745 | non-zero, we are at the end of a level, and we need to prepare to | |
1746 | resume the scan of the lower level. | |
1747 | ||
1748 | If this level's other edge is cached, we simply jump to it, filling | |
1749 | the iterator structure with the iterator state on the other edge. | |
182ce2d2 EZ |
1750 | Otherwise, we walk the buffer or string until we come back to the |
1751 | same level as LEVEL. | |
b7b65b15 EZ |
1752 | |
1753 | Note: we are not talking here about a ``level run'' in the UAX#9 | |
1754 | sense of the term, but rather about a ``level'' which includes | |
1755 | all the levels higher than it. In other words, given the levels | |
1756 | like this: | |
1757 | ||
1758 | 11111112222222333333334443343222222111111112223322111 | |
1759 | A B C | |
1760 | ||
1761 | and assuming we are at point A scanning left to right, this | |
1762 | function moves to point C, whereas the UAX#9 ``level 2 run'' ends | |
1763 | at point B. */ | |
1764 | static void | |
1765 | bidi_find_other_level_edge (struct bidi_it *bidi_it, int level, int end_flag) | |
1766 | { | |
1767 | int dir = end_flag ? -bidi_it->scan_dir : bidi_it->scan_dir; | |
1768 | int idx; | |
1769 | ||
1770 | /* Try the cache first. */ | |
1771 | if ((idx = bidi_cache_find_level_change (level, dir, end_flag)) >= 0) | |
1772 | bidi_cache_fetch_state (idx, bidi_it); | |
1773 | else | |
1774 | { | |
1775 | int new_level; | |
1776 | ||
1777 | if (end_flag) | |
1778 | abort (); /* if we are at end of level, its edges must be cached */ | |
1779 | ||
1780 | bidi_cache_iterator_state (bidi_it, 1); | |
1781 | do { | |
1782 | new_level = bidi_level_of_next_char (bidi_it); | |
1783 | bidi_cache_iterator_state (bidi_it, 1); | |
1784 | } while (new_level >= level); | |
1785 | } | |
1786 | } | |
1787 | ||
1788 | void | |
4b292a22 | 1789 | bidi_move_to_visually_next (struct bidi_it *bidi_it) |
b7b65b15 EZ |
1790 | { |
1791 | int old_level, new_level, next_level; | |
9c82e145 | 1792 | struct bidi_it sentinel; |
b7b65b15 EZ |
1793 | |
1794 | if (bidi_it->scan_dir == 0) | |
1795 | { | |
1796 | bidi_it->scan_dir = 1; /* default to logical order */ | |
1797 | } | |
1798 | ||
be39f003 EZ |
1799 | /* If we just passed a newline, initialize for the next line. */ |
1800 | if (!bidi_it->first_elt && bidi_it->orig_type == NEUTRAL_B) | |
1801 | bidi_line_init (bidi_it); | |
1802 | ||
6dcfd253 EZ |
1803 | /* Prepare the sentinel iterator state, and cache it. When we bump |
1804 | into it, scanning backwards, we'll know that the last non-base | |
1805 | level is exhausted. */ | |
b7b65b15 | 1806 | if (bidi_cache_idx == 0) |
9c82e145 EZ |
1807 | { |
1808 | bidi_copy_it (&sentinel, bidi_it); | |
1809 | if (bidi_it->first_elt) | |
1810 | { | |
1811 | sentinel.charpos--; /* cached charpos needs to be monotonic */ | |
1812 | sentinel.bytepos--; | |
1813 | sentinel.ch = '\n'; /* doesn't matter, but why not? */ | |
1814 | sentinel.ch_len = 1; | |
182ce2d2 | 1815 | sentinel.nchars = 1; |
9c82e145 | 1816 | } |
6dcfd253 | 1817 | bidi_cache_iterator_state (&sentinel, 1); |
9c82e145 | 1818 | } |
b7b65b15 EZ |
1819 | |
1820 | old_level = bidi_it->resolved_level; | |
1821 | new_level = bidi_level_of_next_char (bidi_it); | |
b7b65b15 EZ |
1822 | |
1823 | /* Reordering of resolved levels (clause L2) is implemented by | |
1824 | jumping to the other edge of the level and flipping direction of | |
c0546589 | 1825 | scanning the text whenever we find a level change. */ |
b7b65b15 EZ |
1826 | if (new_level != old_level) |
1827 | { | |
1828 | int ascending = new_level > old_level; | |
1829 | int level_to_search = ascending ? old_level + 1 : old_level; | |
1830 | int incr = ascending ? 1 : -1; | |
1831 | int expected_next_level = old_level + incr; | |
1832 | ||
b7b65b15 EZ |
1833 | /* Jump (or walk) to the other edge of this level. */ |
1834 | bidi_find_other_level_edge (bidi_it, level_to_search, !ascending); | |
1835 | /* Switch scan direction and peek at the next character in the | |
1836 | new direction. */ | |
1837 | bidi_it->scan_dir = -bidi_it->scan_dir; | |
1838 | ||
1839 | /* The following loop handles the case where the resolved level | |
1840 | jumps by more than one. This is typical for numbers inside a | |
1841 | run of text with left-to-right embedding direction, but can | |
1842 | also happen in other situations. In those cases the decision | |
1843 | where to continue after a level change, and in what direction, | |
1844 | is tricky. For example, given a text like below: | |
1845 | ||
1846 | abcdefgh | |
1847 | 11336622 | |
1848 | ||
1849 | (where the numbers below the text show the resolved levels), | |
1850 | the result of reordering according to UAX#9 should be this: | |
1851 | ||
1852 | efdcghba | |
1853 | ||
1854 | This is implemented by the loop below which flips direction | |
1855 | and jumps to the other edge of the level each time it finds | |
1856 | the new level not to be the expected one. The expected level | |
1857 | is always one more or one less than the previous one. */ | |
1858 | next_level = bidi_peek_at_next_level (bidi_it); | |
1859 | while (next_level != expected_next_level) | |
1860 | { | |
1861 | expected_next_level += incr; | |
1862 | level_to_search += incr; | |
1863 | bidi_find_other_level_edge (bidi_it, level_to_search, !ascending); | |
1864 | bidi_it->scan_dir = -bidi_it->scan_dir; | |
1865 | next_level = bidi_peek_at_next_level (bidi_it); | |
1866 | } | |
1867 | ||
1868 | /* Finally, deliver the next character in the new direction. */ | |
1869 | next_level = bidi_level_of_next_char (bidi_it); | |
1870 | } | |
1871 | ||
b44d9321 EZ |
1872 | /* Take note when we have just processed the newline that precedes |
1873 | the end of the paragraph. The next time we are about to be | |
1874 | called, set_iterator_to_next will automatically reinit the | |
1875 | paragraph direction, if needed. We do this at the newline before | |
1876 | the paragraph separator, because the next character might not be | |
1877 | the first character of the next paragraph, due to the bidi | |
c0546589 EZ |
1878 | reordering, whereas we _must_ know the paragraph base direction |
1879 | _before_ we process the paragraph's text, since the base | |
1880 | direction affects the reordering. */ | |
6bff6497 | 1881 | if (bidi_it->scan_dir == 1 |
be39f003 EZ |
1882 | && bidi_it->orig_type == NEUTRAL_B |
1883 | && bidi_it->bytepos < ZV_BYTE) | |
1884 | { | |
1885 | EMACS_INT sep_len = | |
182ce2d2 | 1886 | bidi_at_paragraph_end (bidi_it->charpos + bidi_it->nchars, |
be39f003 | 1887 | bidi_it->bytepos + bidi_it->ch_len); |
102ebb00 EZ |
1888 | if (bidi_it->nchars <= 0) |
1889 | abort (); | |
be39f003 EZ |
1890 | if (sep_len >= 0) |
1891 | { | |
1892 | bidi_it->new_paragraph = 1; | |
b44d9321 EZ |
1893 | /* Record the buffer position of the last character of the |
1894 | paragraph separator. */ | |
182ce2d2 EZ |
1895 | bidi_it->separator_limit = |
1896 | bidi_it->charpos + bidi_it->nchars + sep_len; | |
be39f003 EZ |
1897 | } |
1898 | } | |
6bff6497 | 1899 | |
b7b65b15 EZ |
1900 | if (bidi_it->scan_dir == 1 && bidi_cache_idx) |
1901 | { | |
1902 | /* If we are at paragraph's base embedding level and beyond the | |
1903 | last cached position, the cache's job is done and we can | |
1904 | discard it. */ | |
1905 | if (bidi_it->resolved_level == bidi_it->level_stack[0].level | |
182ce2d2 EZ |
1906 | && bidi_it->charpos > (bidi_cache[bidi_cache_idx - 1].charpos |
1907 | + bidi_cache[bidi_cache_idx - 1].nchars - 1)) | |
b7b65b15 EZ |
1908 | bidi_cache_reset (); |
1909 | /* But as long as we are caching during forward scan, we must | |
1910 | cache each state, or else the cache integrity will be | |
1911 | compromised: it assumes cached states correspond to buffer | |
1912 | positions 1:1. */ | |
1913 | else | |
1914 | bidi_cache_iterator_state (bidi_it, 1); | |
1915 | } | |
1916 | } | |
1917 | ||
1918 | /* This is meant to be called from within the debugger, whenever you | |
1919 | wish to examine the cache contents. */ | |
e78aecca | 1920 | void bidi_dump_cached_states (void) EXTERNALLY_VISIBLE; |
b7b65b15 EZ |
1921 | void |
1922 | bidi_dump_cached_states (void) | |
1923 | { | |
1924 | int i; | |
1925 | int ndigits = 1; | |
1926 | ||
1927 | if (bidi_cache_idx == 0) | |
1928 | { | |
1929 | fprintf (stderr, "The cache is empty.\n"); | |
1930 | return; | |
1931 | } | |
1932 | fprintf (stderr, "Total of %d state%s in cache:\n", | |
1933 | bidi_cache_idx, bidi_cache_idx == 1 ? "" : "s"); | |
1934 | ||
1935 | for (i = bidi_cache[bidi_cache_idx - 1].charpos; i > 0; i /= 10) | |
1936 | ndigits++; | |
1937 | fputs ("ch ", stderr); | |
1938 | for (i = 0; i < bidi_cache_idx; i++) | |
1939 | fprintf (stderr, "%*c", ndigits, bidi_cache[i].ch); | |
1940 | fputs ("\n", stderr); | |
1941 | fputs ("lvl ", stderr); | |
1942 | for (i = 0; i < bidi_cache_idx; i++) | |
1943 | fprintf (stderr, "%*d", ndigits, bidi_cache[i].resolved_level); | |
1944 | fputs ("\n", stderr); | |
1945 | fputs ("pos ", stderr); | |
1946 | for (i = 0; i < bidi_cache_idx; i++) | |
c2982e87 | 1947 | fprintf (stderr, "%*"pI"d", ndigits, bidi_cache[i].charpos); |
b7b65b15 EZ |
1948 | fputs ("\n", stderr); |
1949 | } |