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cbb09f04 | 1 | /* Low-level bidirectional buffer/string-scanning functions for GNU Emacs. |
ab422c4d PE |
2 | Copyright (C) 2000-2001, 2004-2005, 2009-2013 Free Software |
3 | 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, | |
cbb09f04 | 23 | (UBA) as per UAX#9, a part of the Unicode Standard. |
b7b65b15 EZ |
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 | ||
95e1afc6 | 38 | Two other entry points are bidi_paragraph_init and |
940afb59 EZ |
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 | ||
95e1afc6 EZ |
43 | A few auxiliary entry points are used to initialize the bidi |
44 | iterator for iterating an object (buffer or string), push and pop | |
45 | the bidi iterator state, and save and restore the state of the bidi | |
46 | cache. | |
47 | ||
89d3374a EZ |
48 | If you want to understand the code, you will have to read it |
49 | together with the relevant portions of UAX#9. The comments include | |
50 | references to UAX#9 rules, for that very reason. | |
51 | ||
b7b65b15 EZ |
52 | A note about references to UAX#9 rules: if the reference says |
53 | something like "X9/Retaining", it means that you need to refer to | |
cd1181db | 54 | rule X9 and to its modifications described in the "Implementation |
b7b65b15 EZ |
55 | Notes" section of UAX#9, under "Retaining Format Codes". */ |
56 | ||
b7b65b15 | 57 | #include <config.h> |
b7b65b15 | 58 | #include <stdio.h> |
29e3d8d1 | 59 | |
b7b65b15 | 60 | #include "lisp.h" |
b7b65b15 | 61 | #include "character.h" |
e5560ff7 | 62 | #include "buffer.h" |
b7b65b15 | 63 | #include "dispextern.h" |
e30b79c1 | 64 | #include "region-cache.h" |
b7b65b15 | 65 | |
2cc21167 | 66 | static bool bidi_initialized = 0; |
b7b65b15 | 67 | |
cbc4fd20 | 68 | static Lisp_Object bidi_type_table, bidi_mirror_table; |
b7b65b15 EZ |
69 | |
70 | #define LRM_CHAR 0x200E | |
71 | #define RLM_CHAR 0x200F | |
b7b65b15 | 72 | #define BIDI_EOB -1 |
b7b65b15 | 73 | |
b7b65b15 EZ |
74 | /* Data type for describing the bidirectional character categories. */ |
75 | typedef enum { | |
76 | UNKNOWN_BC, | |
77 | NEUTRAL, | |
78 | WEAK, | |
79 | STRONG | |
80 | } bidi_category_t; | |
81 | ||
32413314 EZ |
82 | /* UAX#9 says to search only for L, AL, or R types of characters, and |
83 | ignore RLE, RLO, LRE, and LRO, when determining the base paragraph | |
84 | level. Yudit indeed ignores them. This variable is therefore set | |
2cc21167 PE |
85 | by default to ignore them, but clearing it will take them into |
86 | account. */ | |
87 | extern bool bidi_ignore_explicit_marks_for_paragraph_level EXTERNALLY_VISIBLE; | |
88 | bool bidi_ignore_explicit_marks_for_paragraph_level = 1; | |
b7b65b15 | 89 | |
372b7a95 | 90 | static Lisp_Object paragraph_start_re, paragraph_separate_re; |
6bff6497 | 91 | static Lisp_Object Qparagraph_start, Qparagraph_separate; |
b7b65b15 | 92 | |
cbb09f04 EZ |
93 | \f |
94 | /*********************************************************************** | |
95 | Utilities | |
96 | ***********************************************************************/ | |
b7b65b15 | 97 | |
6bff6497 EZ |
98 | /* Return the bidi type of a character CH, subject to the current |
99 | directional OVERRIDE. */ | |
0a99eee1 | 100 | static bidi_type_t |
6bff6497 | 101 | bidi_get_type (int ch, bidi_dir_t override) |
b7b65b15 | 102 | { |
6bff6497 EZ |
103 | bidi_type_t default_type; |
104 | ||
e7402cb2 EZ |
105 | if (ch == BIDI_EOB) |
106 | return NEUTRAL_B; | |
e342a24d | 107 | if (ch < 0 || ch > MAX_CHAR) |
1088b922 | 108 | emacs_abort (); |
6bff6497 EZ |
109 | |
110 | default_type = (bidi_type_t) XINT (CHAR_TABLE_REF (bidi_type_table, ch)); | |
bca633fb EZ |
111 | /* Every valid character code, even those that are unassigned by the |
112 | UCD, have some bidi-class property, according to | |
113 | DerivedBidiClass.txt file. Therefore, if we ever get UNKNOWN_BT | |
114 | (= zero) code from CHAR_TABLE_REF, that's a bug. */ | |
115 | if (default_type == UNKNOWN_BT) | |
1088b922 | 116 | emacs_abort (); |
6bff6497 EZ |
117 | |
118 | if (override == NEUTRAL_DIR) | |
119 | return default_type; | |
120 | ||
121 | switch (default_type) | |
122 | { | |
123 | /* Although UAX#9 does not tell, it doesn't make sense to | |
124 | override NEUTRAL_B and LRM/RLM characters. */ | |
125 | case NEUTRAL_B: | |
126 | case LRE: | |
127 | case LRO: | |
128 | case RLE: | |
129 | case RLO: | |
130 | case PDF: | |
131 | return default_type; | |
132 | default: | |
133 | switch (ch) | |
134 | { | |
135 | case LRM_CHAR: | |
136 | case RLM_CHAR: | |
137 | return default_type; | |
138 | default: | |
139 | if (override == L2R) /* X6 */ | |
140 | return STRONG_L; | |
141 | else if (override == R2L) | |
142 | return STRONG_R; | |
143 | else | |
1088b922 | 144 | emacs_abort (); /* can't happen: handled above */ |
6bff6497 EZ |
145 | } |
146 | } | |
b7b65b15 EZ |
147 | } |
148 | ||
0a99eee1 | 149 | static void |
2d6e4628 EZ |
150 | bidi_check_type (bidi_type_t type) |
151 | { | |
a54e2c05 | 152 | eassert (UNKNOWN_BT <= type && type <= NEUTRAL_ON); |
2d6e4628 EZ |
153 | } |
154 | ||
b7b65b15 | 155 | /* Given a bidi TYPE of a character, return its category. */ |
0a99eee1 | 156 | static bidi_category_t |
b7b65b15 EZ |
157 | bidi_get_category (bidi_type_t type) |
158 | { | |
159 | switch (type) | |
160 | { | |
161 | case UNKNOWN_BT: | |
162 | return UNKNOWN_BC; | |
163 | case STRONG_L: | |
164 | case STRONG_R: | |
165 | case STRONG_AL: | |
166 | case LRE: | |
167 | case LRO: | |
168 | case RLE: | |
169 | case RLO: | |
170 | return STRONG; | |
171 | case PDF: /* ??? really?? */ | |
172 | case WEAK_EN: | |
173 | case WEAK_ES: | |
174 | case WEAK_ET: | |
175 | case WEAK_AN: | |
176 | case WEAK_CS: | |
177 | case WEAK_NSM: | |
178 | case WEAK_BN: | |
179 | return WEAK; | |
180 | case NEUTRAL_B: | |
181 | case NEUTRAL_S: | |
182 | case NEUTRAL_WS: | |
183 | case NEUTRAL_ON: | |
184 | return NEUTRAL; | |
185 | default: | |
1088b922 | 186 | emacs_abort (); |
b7b65b15 EZ |
187 | } |
188 | } | |
189 | ||
a6e8d97c EZ |
190 | /* Return the mirrored character of C, if it has one. If C has no |
191 | mirrored counterpart, return C. | |
192 | Note: The conditions in UAX#9 clause L4 regarding the surrounding | |
193 | context must be tested by the caller. */ | |
b7b65b15 EZ |
194 | int |
195 | bidi_mirror_char (int c) | |
196 | { | |
cbc4fd20 EZ |
197 | Lisp_Object val; |
198 | ||
199 | if (c == BIDI_EOB) | |
200 | return c; | |
201 | if (c < 0 || c > MAX_CHAR) | |
1088b922 | 202 | emacs_abort (); |
b7b65b15 | 203 | |
cbc4fd20 EZ |
204 | val = CHAR_TABLE_REF (bidi_mirror_table, c); |
205 | if (INTEGERP (val)) | |
b7b65b15 | 206 | { |
da92a98c | 207 | int v; |
9e1a06fc | 208 | |
da92a98c PE |
209 | /* When debugging, check before assigning to V, so that the check |
210 | isn't broken by undefined behavior due to int overflow. */ | |
81899c91 | 211 | eassert (CHAR_VALID_P (XINT (val))); |
9e1a06fc | 212 | |
da92a98c PE |
213 | v = XINT (val); |
214 | ||
9e1a06fc EZ |
215 | /* Minimal test we must do in optimized builds, to prevent weird |
216 | crashes further down the road. */ | |
217 | if (v < 0 || v > MAX_CHAR) | |
1088b922 | 218 | emacs_abort (); |
9e1a06fc EZ |
219 | |
220 | return v; | |
b7b65b15 | 221 | } |
cbc4fd20 | 222 | |
b7b65b15 EZ |
223 | return c; |
224 | } | |
225 | ||
cbb09f04 EZ |
226 | /* Determine the start-of-run (sor) directional type given the two |
227 | embedding levels on either side of the run boundary. Also, update | |
228 | the saved info about previously seen characters, since that info is | |
229 | generally valid for a single level run. */ | |
0a99eee1 | 230 | static void |
cbb09f04 EZ |
231 | bidi_set_sor_type (struct bidi_it *bidi_it, int level_before, int level_after) |
232 | { | |
512a289d | 233 | int higher_level = (level_before > level_after ? level_before : level_after); |
cbb09f04 EZ |
234 | |
235 | /* The prev_was_pdf gork is required for when we have several PDFs | |
236 | in a row. In that case, we want to compute the sor type for the | |
237 | next level run only once: when we see the first PDF. That's | |
238 | because the sor type depends only on the higher of the two levels | |
239 | that we find on the two sides of the level boundary (see UAX#9, | |
240 | clause X10), and so we don't need to know the final embedding | |
241 | level to which we descend after processing all the PDFs. */ | |
242 | if (!bidi_it->prev_was_pdf || level_before < level_after) | |
243 | /* FIXME: should the default sor direction be user selectable? */ | |
512a289d | 244 | bidi_it->sor = ((higher_level & 1) != 0 ? R2L : L2R); |
cbb09f04 EZ |
245 | if (level_before > level_after) |
246 | bidi_it->prev_was_pdf = 1; | |
247 | ||
248 | bidi_it->prev.type = UNKNOWN_BT; | |
512a289d RS |
249 | bidi_it->last_strong.type = bidi_it->last_strong.type_after_w1 |
250 | = bidi_it->last_strong.orig_type = UNKNOWN_BT; | |
251 | bidi_it->prev_for_neutral.type = (bidi_it->sor == R2L ? STRONG_R : STRONG_L); | |
cbb09f04 EZ |
252 | bidi_it->prev_for_neutral.charpos = bidi_it->charpos; |
253 | bidi_it->prev_for_neutral.bytepos = bidi_it->bytepos; | |
512a289d RS |
254 | bidi_it->next_for_neutral.type = bidi_it->next_for_neutral.type_after_w1 |
255 | = bidi_it->next_for_neutral.orig_type = UNKNOWN_BT; | |
cbb09f04 EZ |
256 | bidi_it->ignore_bn_limit = -1; /* meaning it's unknown */ |
257 | } | |
258 | ||
259 | /* Push the current embedding level and override status; reset the | |
260 | current level to LEVEL and the current override status to OVERRIDE. */ | |
0a99eee1 | 261 | static void |
cbb09f04 EZ |
262 | bidi_push_embedding_level (struct bidi_it *bidi_it, |
263 | int level, bidi_dir_t override) | |
264 | { | |
265 | bidi_it->stack_idx++; | |
a54e2c05 | 266 | eassert (bidi_it->stack_idx < BIDI_MAXLEVEL); |
cbb09f04 EZ |
267 | bidi_it->level_stack[bidi_it->stack_idx].level = level; |
268 | bidi_it->level_stack[bidi_it->stack_idx].override = override; | |
269 | } | |
270 | ||
271 | /* Pop the embedding level and directional override status from the | |
272 | stack, and return the new level. */ | |
0a99eee1 | 273 | static int |
cbb09f04 EZ |
274 | bidi_pop_embedding_level (struct bidi_it *bidi_it) |
275 | { | |
276 | /* UAX#9 says to ignore invalid PDFs. */ | |
277 | if (bidi_it->stack_idx > 0) | |
278 | bidi_it->stack_idx--; | |
279 | return bidi_it->level_stack[bidi_it->stack_idx].level; | |
280 | } | |
281 | ||
282 | /* Record in SAVED_INFO the information about the current character. */ | |
0a99eee1 | 283 | static void |
cbb09f04 EZ |
284 | bidi_remember_char (struct bidi_saved_info *saved_info, |
285 | struct bidi_it *bidi_it) | |
286 | { | |
287 | saved_info->charpos = bidi_it->charpos; | |
288 | saved_info->bytepos = bidi_it->bytepos; | |
289 | saved_info->type = bidi_it->type; | |
290 | bidi_check_type (bidi_it->type); | |
291 | saved_info->type_after_w1 = bidi_it->type_after_w1; | |
292 | bidi_check_type (bidi_it->type_after_w1); | |
293 | saved_info->orig_type = bidi_it->orig_type; | |
294 | bidi_check_type (bidi_it->orig_type); | |
295 | } | |
296 | ||
b7b65b15 EZ |
297 | /* Copy the bidi iterator from FROM to TO. To save cycles, this only |
298 | copies the part of the level stack that is actually in use. */ | |
0a99eee1 | 299 | static void |
b7b65b15 EZ |
300 | bidi_copy_it (struct bidi_it *to, struct bidi_it *from) |
301 | { | |
05584c31 PE |
302 | /* Copy everything from the start through the active part of |
303 | the level stack. */ | |
304 | memcpy (to, from, | |
305 | (offsetof (struct bidi_it, level_stack[1]) | |
306 | + from->stack_idx * sizeof from->level_stack[0])); | |
b7b65b15 EZ |
307 | } |
308 | ||
cbb09f04 EZ |
309 | \f |
310 | /*********************************************************************** | |
311 | Caching the bidi iterator states | |
312 | ***********************************************************************/ | |
b7b65b15 | 313 | |
2fe72643 EZ |
314 | #define BIDI_CACHE_CHUNK 200 |
315 | static struct bidi_it *bidi_cache; | |
39e378da | 316 | static ptrdiff_t bidi_cache_size = 0; |
ad6042bb | 317 | enum { elsz = sizeof (struct bidi_it) }; |
39e378da PE |
318 | static ptrdiff_t bidi_cache_idx; /* next unused cache slot */ |
319 | static ptrdiff_t bidi_cache_last_idx; /* slot of last cache hit */ | |
320 | static ptrdiff_t bidi_cache_start = 0; /* start of cache for this | |
87e67904 EZ |
321 | "stack" level */ |
322 | ||
bc18e09d PE |
323 | /* 5-slot stack for saving the start of the previous level of the |
324 | cache. xdisp.c maintains a 5-slot stack for its iterator state, | |
325 | and we need the same size of our stack. */ | |
326 | static ptrdiff_t bidi_cache_start_stack[IT_STACK_SIZE]; | |
327 | static int bidi_cache_sp; | |
328 | ||
329 | /* Size of header used by bidi_shelve_cache. */ | |
330 | enum | |
331 | { | |
512a289d RS |
332 | bidi_shelve_header_size |
333 | = (sizeof (bidi_cache_idx) + sizeof (bidi_cache_start_stack) | |
334 | + sizeof (bidi_cache_sp) + sizeof (bidi_cache_start) | |
335 | + sizeof (bidi_cache_last_idx)) | |
bc18e09d PE |
336 | }; |
337 | ||
87e67904 EZ |
338 | /* Reset the cache state to the empty state. We only reset the part |
339 | of the cache relevant to iteration of the current object. Previous | |
340 | objects, which are pushed on the display iterator's stack, are left | |
341 | intact. This is called when the cached information is no more | |
342 | useful for the current iteration, e.g. when we were reseated to a | |
343 | new position on the same object. */ | |
0a99eee1 | 344 | static void |
b7b65b15 EZ |
345 | bidi_cache_reset (void) |
346 | { | |
87e67904 | 347 | bidi_cache_idx = bidi_cache_start; |
b7b65b15 EZ |
348 | bidi_cache_last_idx = -1; |
349 | } | |
350 | ||
87e67904 EZ |
351 | /* Shrink the cache to its minimal size. Called when we init the bidi |
352 | iterator for reordering a buffer or a string that does not come | |
353 | from display properties, because that means all the previously | |
354 | cached info is of no further use. */ | |
0a99eee1 | 355 | static void |
2fe72643 EZ |
356 | bidi_cache_shrink (void) |
357 | { | |
358 | if (bidi_cache_size > BIDI_CACHE_CHUNK) | |
359 | { | |
38182d90 | 360 | bidi_cache = xrealloc (bidi_cache, BIDI_CACHE_CHUNK * elsz); |
51f30bc5 | 361 | bidi_cache_size = BIDI_CACHE_CHUNK; |
2fe72643 EZ |
362 | } |
363 | bidi_cache_reset (); | |
364 | } | |
365 | ||
0a99eee1 | 366 | static void |
39e378da | 367 | bidi_cache_fetch_state (ptrdiff_t idx, struct bidi_it *bidi_it) |
b7b65b15 EZ |
368 | { |
369 | int current_scan_dir = bidi_it->scan_dir; | |
370 | ||
87e67904 | 371 | if (idx < bidi_cache_start || idx >= bidi_cache_idx) |
1088b922 | 372 | emacs_abort (); |
b7b65b15 EZ |
373 | |
374 | bidi_copy_it (bidi_it, &bidi_cache[idx]); | |
375 | bidi_it->scan_dir = current_scan_dir; | |
376 | bidi_cache_last_idx = idx; | |
377 | } | |
378 | ||
379 | /* Find a cached state with a given CHARPOS and resolved embedding | |
380 | level less or equal to LEVEL. if LEVEL is -1, disregard the | |
381 | resolved levels in cached states. DIR, if non-zero, means search | |
382 | in that direction from the last cache hit. */ | |
0a99eee1 | 383 | static ptrdiff_t |
d311d28c | 384 | bidi_cache_search (ptrdiff_t charpos, int level, int dir) |
b7b65b15 | 385 | { |
39e378da | 386 | ptrdiff_t i, i_start; |
b7b65b15 | 387 | |
6eec7596 | 388 | if (bidi_cache_idx > bidi_cache_start) |
b7b65b15 | 389 | { |
6eec7596 EZ |
390 | if (bidi_cache_last_idx == -1) |
391 | bidi_cache_last_idx = bidi_cache_idx - 1; | |
b7b65b15 | 392 | if (charpos < bidi_cache[bidi_cache_last_idx].charpos) |
182ce2d2 EZ |
393 | { |
394 | dir = -1; | |
395 | i_start = bidi_cache_last_idx - 1; | |
396 | } | |
397 | else if (charpos > (bidi_cache[bidi_cache_last_idx].charpos | |
398 | + bidi_cache[bidi_cache_last_idx].nchars - 1)) | |
399 | { | |
400 | dir = 1; | |
401 | i_start = bidi_cache_last_idx + 1; | |
402 | } | |
403 | else if (dir) | |
b7b65b15 EZ |
404 | i_start = bidi_cache_last_idx; |
405 | else | |
406 | { | |
407 | dir = -1; | |
408 | i_start = bidi_cache_idx - 1; | |
409 | } | |
410 | ||
411 | if (dir < 0) | |
412 | { | |
413 | /* Linear search for now; FIXME! */ | |
87e67904 | 414 | for (i = i_start; i >= bidi_cache_start; i--) |
182ce2d2 EZ |
415 | if (bidi_cache[i].charpos <= charpos |
416 | && charpos < bidi_cache[i].charpos + bidi_cache[i].nchars | |
b7b65b15 EZ |
417 | && (level == -1 || bidi_cache[i].resolved_level <= level)) |
418 | return i; | |
419 | } | |
420 | else | |
421 | { | |
422 | for (i = i_start; i < bidi_cache_idx; i++) | |
182ce2d2 EZ |
423 | if (bidi_cache[i].charpos <= charpos |
424 | && charpos < bidi_cache[i].charpos + bidi_cache[i].nchars | |
b7b65b15 EZ |
425 | && (level == -1 || bidi_cache[i].resolved_level <= level)) |
426 | return i; | |
427 | } | |
428 | } | |
429 | ||
430 | return -1; | |
431 | } | |
432 | ||
433 | /* Find a cached state where the resolved level changes to a value | |
434 | that is lower than LEVEL, and return its cache slot index. DIR is | |
435 | the direction to search, starting with the last used cache slot. | |
87e67904 | 436 | If DIR is zero, we search backwards from the last occupied cache |
2cc21167 | 437 | slot. BEFORE means return the index of the slot that |
87e67904 | 438 | is ``before'' the level change in the search direction. That is, |
b7b65b15 EZ |
439 | given the cached levels like this: |
440 | ||
441 | 1122333442211 | |
442 | AB C | |
443 | ||
444 | and assuming we are at the position cached at the slot marked with | |
445 | C, searching backwards (DIR = -1) for LEVEL = 2 will return the | |
446 | index of slot B or A, depending whether BEFORE is, respectively, | |
2cc21167 | 447 | true or false. */ |
39e378da | 448 | static ptrdiff_t |
2cc21167 | 449 | bidi_cache_find_level_change (int level, int dir, bool before) |
b7b65b15 EZ |
450 | { |
451 | if (bidi_cache_idx) | |
452 | { | |
39e378da | 453 | ptrdiff_t i = dir ? bidi_cache_last_idx : bidi_cache_idx - 1; |
b7b65b15 EZ |
454 | int incr = before ? 1 : 0; |
455 | ||
a54e2c05 | 456 | eassert (!dir || bidi_cache_last_idx >= 0); |
6eec7596 | 457 | |
b7b65b15 EZ |
458 | if (!dir) |
459 | dir = -1; | |
460 | else if (!incr) | |
461 | i += dir; | |
462 | ||
463 | if (dir < 0) | |
464 | { | |
87e67904 | 465 | while (i >= bidi_cache_start + incr) |
b7b65b15 EZ |
466 | { |
467 | if (bidi_cache[i - incr].resolved_level >= 0 | |
468 | && bidi_cache[i - incr].resolved_level < level) | |
469 | return i; | |
470 | i--; | |
471 | } | |
472 | } | |
473 | else | |
474 | { | |
475 | while (i < bidi_cache_idx - incr) | |
476 | { | |
477 | if (bidi_cache[i + incr].resolved_level >= 0 | |
478 | && bidi_cache[i + incr].resolved_level < level) | |
479 | return i; | |
480 | i++; | |
481 | } | |
482 | } | |
483 | } | |
484 | ||
485 | return -1; | |
486 | } | |
487 | ||
0a99eee1 | 488 | static void |
39e378da | 489 | bidi_cache_ensure_space (ptrdiff_t idx) |
58b9f433 EZ |
490 | { |
491 | /* Enlarge the cache as needed. */ | |
492 | if (idx >= bidi_cache_size) | |
493 | { | |
f0eb61e9 PE |
494 | /* The bidi cache cannot be larger than the largest Lisp string |
495 | or buffer. */ | |
512a289d RS |
496 | ptrdiff_t string_or_buffer_bound |
497 | = max (BUF_BYTES_MAX, STRING_BYTES_BOUND); | |
f0eb61e9 PE |
498 | |
499 | /* Also, it cannot be larger than what C can represent. */ | |
512a289d RS |
500 | ptrdiff_t c_bound |
501 | = (min (PTRDIFF_MAX, SIZE_MAX) - bidi_shelve_header_size) / elsz; | |
f0eb61e9 | 502 | |
512a289d RS |
503 | bidi_cache |
504 | = xpalloc (bidi_cache, &bidi_cache_size, | |
505 | max (BIDI_CACHE_CHUNK, idx - bidi_cache_size + 1), | |
506 | min (string_or_buffer_bound, c_bound), elsz); | |
58b9f433 EZ |
507 | } |
508 | } | |
509 | ||
0a99eee1 | 510 | static void |
2cc21167 | 511 | bidi_cache_iterator_state (struct bidi_it *bidi_it, bool resolved) |
b7b65b15 | 512 | { |
39e378da | 513 | ptrdiff_t idx; |
b7b65b15 EZ |
514 | |
515 | /* We should never cache on backward scans. */ | |
516 | if (bidi_it->scan_dir == -1) | |
1088b922 | 517 | emacs_abort (); |
b7b65b15 EZ |
518 | idx = bidi_cache_search (bidi_it->charpos, -1, 1); |
519 | ||
520 | if (idx < 0) | |
521 | { | |
522 | idx = bidi_cache_idx; | |
58b9f433 | 523 | bidi_cache_ensure_space (idx); |
bd924a5d EZ |
524 | /* Character positions should correspond to cache positions 1:1. |
525 | If we are outside the range of cached positions, the cache is | |
526 | useless and must be reset. */ | |
87e67904 | 527 | if (idx > bidi_cache_start && |
182ce2d2 EZ |
528 | (bidi_it->charpos > (bidi_cache[idx - 1].charpos |
529 | + bidi_cache[idx - 1].nchars) | |
a1344e7d | 530 | || bidi_it->charpos < bidi_cache[bidi_cache_start].charpos)) |
bd924a5d EZ |
531 | { |
532 | bidi_cache_reset (); | |
87e67904 | 533 | idx = bidi_cache_start; |
bd924a5d | 534 | } |
102ebb00 | 535 | if (bidi_it->nchars <= 0) |
1088b922 | 536 | emacs_abort (); |
b7b65b15 EZ |
537 | bidi_copy_it (&bidi_cache[idx], bidi_it); |
538 | if (!resolved) | |
539 | bidi_cache[idx].resolved_level = -1; | |
540 | } | |
541 | else | |
542 | { | |
543 | /* Copy only the members which could have changed, to avoid | |
544 | costly copying of the entire struct. */ | |
545 | bidi_cache[idx].type = bidi_it->type; | |
2d6e4628 | 546 | bidi_check_type (bidi_it->type); |
89d3374a EZ |
547 | bidi_cache[idx].type_after_w1 = bidi_it->type_after_w1; |
548 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 EZ |
549 | if (resolved) |
550 | bidi_cache[idx].resolved_level = bidi_it->resolved_level; | |
551 | else | |
552 | bidi_cache[idx].resolved_level = -1; | |
553 | bidi_cache[idx].invalid_levels = bidi_it->invalid_levels; | |
554 | bidi_cache[idx].invalid_rl_levels = bidi_it->invalid_rl_levels; | |
555 | bidi_cache[idx].next_for_neutral = bidi_it->next_for_neutral; | |
556 | bidi_cache[idx].next_for_ws = bidi_it->next_for_ws; | |
557 | bidi_cache[idx].ignore_bn_limit = bidi_it->ignore_bn_limit; | |
f67cdd7f | 558 | bidi_cache[idx].disp_pos = bidi_it->disp_pos; |
0c95fcf7 | 559 | bidi_cache[idx].disp_prop = bidi_it->disp_prop; |
b7b65b15 EZ |
560 | } |
561 | ||
562 | bidi_cache_last_idx = idx; | |
563 | if (idx >= bidi_cache_idx) | |
564 | bidi_cache_idx = idx + 1; | |
565 | } | |
566 | ||
0a99eee1 | 567 | static bidi_type_t |
d311d28c | 568 | bidi_cache_find (ptrdiff_t charpos, int level, struct bidi_it *bidi_it) |
b7b65b15 | 569 | { |
39e378da | 570 | ptrdiff_t i = bidi_cache_search (charpos, level, bidi_it->scan_dir); |
b7b65b15 | 571 | |
87e67904 | 572 | if (i >= bidi_cache_start) |
b7b65b15 EZ |
573 | { |
574 | bidi_dir_t current_scan_dir = bidi_it->scan_dir; | |
575 | ||
5009f85e | 576 | bidi_copy_it (bidi_it, &bidi_cache[i]); |
b7b65b15 | 577 | bidi_cache_last_idx = i; |
5a5fa834 | 578 | /* Don't let scan direction from the cached state override |
b7b65b15 EZ |
579 | the current scan direction. */ |
580 | bidi_it->scan_dir = current_scan_dir; | |
581 | return bidi_it->type; | |
582 | } | |
583 | ||
584 | return UNKNOWN_BT; | |
585 | } | |
586 | ||
0a99eee1 | 587 | static int |
b7b65b15 EZ |
588 | bidi_peek_at_next_level (struct bidi_it *bidi_it) |
589 | { | |
87e67904 | 590 | if (bidi_cache_idx == bidi_cache_start || bidi_cache_last_idx == -1) |
1088b922 | 591 | emacs_abort (); |
b7b65b15 EZ |
592 | return bidi_cache[bidi_cache_last_idx + bidi_it->scan_dir].resolved_level; |
593 | } | |
594 | ||
cbb09f04 | 595 | \f |
58b9f433 EZ |
596 | /*********************************************************************** |
597 | Pushing and popping the bidi iterator state | |
598 | ***********************************************************************/ | |
58b9f433 EZ |
599 | |
600 | /* Push the bidi iterator state in preparation for reordering a | |
601 | different object, e.g. display string found at certain buffer | |
7e2ad32c EZ |
602 | position. Pushing the bidi iterator boils down to saving its |
603 | entire state on the cache and starting a new cache "stacked" on top | |
604 | of the current cache. */ | |
58b9f433 EZ |
605 | void |
606 | bidi_push_it (struct bidi_it *bidi_it) | |
b7b65b15 | 607 | { |
58b9f433 EZ |
608 | /* Save the current iterator state in its entirety after the last |
609 | used cache slot. */ | |
610 | bidi_cache_ensure_space (bidi_cache_idx); | |
ae1d87e2 | 611 | bidi_cache[bidi_cache_idx++] = *bidi_it; |
be39f003 | 612 | |
58b9f433 | 613 | /* Push the current cache start onto the stack. */ |
a54e2c05 | 614 | eassert (bidi_cache_sp < IT_STACK_SIZE); |
58b9f433 | 615 | bidi_cache_start_stack[bidi_cache_sp++] = bidi_cache_start; |
be39f003 | 616 | |
58b9f433 EZ |
617 | /* Start a new level of cache, and make it empty. */ |
618 | bidi_cache_start = bidi_cache_idx; | |
619 | bidi_cache_last_idx = -1; | |
620 | } | |
621 | ||
622 | /* Restore the iterator state saved by bidi_push_it and return the | |
623 | cache to the corresponding state. */ | |
624 | void | |
625 | bidi_pop_it (struct bidi_it *bidi_it) | |
626 | { | |
627 | if (bidi_cache_start <= 0) | |
1088b922 | 628 | emacs_abort (); |
58b9f433 EZ |
629 | |
630 | /* Reset the next free cache slot index to what it was before the | |
631 | call to bidi_push_it. */ | |
632 | bidi_cache_idx = bidi_cache_start - 1; | |
633 | ||
634 | /* Restore the bidi iterator state saved in the cache. */ | |
ae1d87e2 | 635 | *bidi_it = bidi_cache[bidi_cache_idx]; |
58b9f433 EZ |
636 | |
637 | /* Pop the previous cache start from the stack. */ | |
638 | if (bidi_cache_sp <= 0) | |
1088b922 | 639 | emacs_abort (); |
58b9f433 EZ |
640 | bidi_cache_start = bidi_cache_start_stack[--bidi_cache_sp]; |
641 | ||
642 | /* Invalidate the last-used cache slot data. */ | |
643 | bidi_cache_last_idx = -1; | |
644 | } | |
645 | ||
ec7cc85b | 646 | static ptrdiff_t bidi_cache_total_alloc; |
35928349 | 647 | |
ed94e6d7 EZ |
648 | /* Stash away a copy of the cache and its control variables. */ |
649 | void * | |
650 | bidi_shelve_cache (void) | |
651 | { | |
652 | unsigned char *databuf; | |
458bfed3 | 653 | ptrdiff_t alloc; |
ed94e6d7 | 654 | |
35928349 | 655 | /* Empty cache. */ |
ed94e6d7 EZ |
656 | if (bidi_cache_idx == 0) |
657 | return NULL; | |
658 | ||
458bfed3 PE |
659 | alloc = (bidi_shelve_header_size |
660 | + bidi_cache_idx * sizeof (struct bidi_it)); | |
661 | databuf = xmalloc (alloc); | |
662 | bidi_cache_total_alloc += alloc; | |
35928349 | 663 | |
ed94e6d7 EZ |
664 | memcpy (databuf, &bidi_cache_idx, sizeof (bidi_cache_idx)); |
665 | memcpy (databuf + sizeof (bidi_cache_idx), | |
666 | bidi_cache, bidi_cache_idx * sizeof (struct bidi_it)); | |
667 | memcpy (databuf + sizeof (bidi_cache_idx) | |
668 | + bidi_cache_idx * sizeof (struct bidi_it), | |
669 | bidi_cache_start_stack, sizeof (bidi_cache_start_stack)); | |
670 | memcpy (databuf + sizeof (bidi_cache_idx) | |
671 | + bidi_cache_idx * sizeof (struct bidi_it) | |
672 | + sizeof (bidi_cache_start_stack), | |
673 | &bidi_cache_sp, sizeof (bidi_cache_sp)); | |
674 | memcpy (databuf + sizeof (bidi_cache_idx) | |
675 | + bidi_cache_idx * sizeof (struct bidi_it) | |
676 | + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp), | |
677 | &bidi_cache_start, sizeof (bidi_cache_start)); | |
678 | memcpy (databuf + sizeof (bidi_cache_idx) | |
679 | + bidi_cache_idx * sizeof (struct bidi_it) | |
680 | + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp) | |
681 | + sizeof (bidi_cache_start), | |
682 | &bidi_cache_last_idx, sizeof (bidi_cache_last_idx)); | |
683 | ||
684 | return databuf; | |
685 | } | |
686 | ||
d1410150 EZ |
687 | /* Restore the cache state from a copy stashed away by |
688 | bidi_shelve_cache, and free the buffer used to stash that copy. | |
2cc21167 | 689 | JUST_FREE means free the buffer, but don't restore the |
d1410150 EZ |
690 | cache; used when the corresponding iterator is discarded instead of |
691 | being restored. */ | |
ed94e6d7 | 692 | void |
2cc21167 | 693 | bidi_unshelve_cache (void *databuf, bool just_free) |
ed94e6d7 EZ |
694 | { |
695 | unsigned char *p = databuf; | |
696 | ||
697 | if (!p) | |
be39f003 | 698 | { |
d1410150 EZ |
699 | if (!just_free) |
700 | { | |
701 | /* A NULL pointer means an empty cache. */ | |
702 | bidi_cache_start = 0; | |
703 | bidi_cache_sp = 0; | |
704 | bidi_cache_reset (); | |
705 | } | |
be39f003 | 706 | } |
ed94e6d7 EZ |
707 | else |
708 | { | |
35928349 EZ |
709 | if (just_free) |
710 | { | |
711 | ptrdiff_t idx; | |
712 | ||
713 | memcpy (&idx, p, sizeof (bidi_cache_idx)); | |
512a289d RS |
714 | bidi_cache_total_alloc |
715 | -= bidi_shelve_header_size + idx * sizeof (struct bidi_it); | |
35928349 EZ |
716 | } |
717 | else | |
718 | { | |
719 | memcpy (&bidi_cache_idx, p, sizeof (bidi_cache_idx)); | |
720 | bidi_cache_ensure_space (bidi_cache_idx); | |
721 | memcpy (bidi_cache, p + sizeof (bidi_cache_idx), | |
722 | bidi_cache_idx * sizeof (struct bidi_it)); | |
723 | memcpy (bidi_cache_start_stack, | |
724 | p + sizeof (bidi_cache_idx) | |
725 | + bidi_cache_idx * sizeof (struct bidi_it), | |
726 | sizeof (bidi_cache_start_stack)); | |
727 | memcpy (&bidi_cache_sp, | |
728 | p + sizeof (bidi_cache_idx) | |
729 | + bidi_cache_idx * sizeof (struct bidi_it) | |
730 | + sizeof (bidi_cache_start_stack), | |
731 | sizeof (bidi_cache_sp)); | |
732 | memcpy (&bidi_cache_start, | |
733 | p + sizeof (bidi_cache_idx) | |
734 | + bidi_cache_idx * sizeof (struct bidi_it) | |
735 | + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp), | |
736 | sizeof (bidi_cache_start)); | |
737 | memcpy (&bidi_cache_last_idx, | |
738 | p + sizeof (bidi_cache_idx) | |
739 | + bidi_cache_idx * sizeof (struct bidi_it) | |
740 | + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp) | |
741 | + sizeof (bidi_cache_start), | |
742 | sizeof (bidi_cache_last_idx)); | |
512a289d RS |
743 | bidi_cache_total_alloc |
744 | -= (bidi_shelve_header_size | |
745 | + bidi_cache_idx * sizeof (struct bidi_it)); | |
35928349 | 746 | } |
ed94e6d7 EZ |
747 | |
748 | xfree (p); | |
749 | } | |
750 | } | |
b7b65b15 | 751 | |
58b9f433 | 752 | \f |
cbb09f04 EZ |
753 | /*********************************************************************** |
754 | Initialization | |
755 | ***********************************************************************/ | |
756 | static void | |
757 | bidi_initialize (void) | |
b7b65b15 | 758 | { |
474a8465 EZ |
759 | bidi_type_table = uniprop_table (intern ("bidi-class")); |
760 | if (NILP (bidi_type_table)) | |
1088b922 | 761 | emacs_abort (); |
cbb09f04 EZ |
762 | staticpro (&bidi_type_table); |
763 | ||
474a8465 EZ |
764 | bidi_mirror_table = uniprop_table (intern ("mirroring")); |
765 | if (NILP (bidi_mirror_table)) | |
1088b922 | 766 | emacs_abort (); |
cbb09f04 EZ |
767 | staticpro (&bidi_mirror_table); |
768 | ||
cbb09f04 EZ |
769 | Qparagraph_start = intern ("paragraph-start"); |
770 | staticpro (&Qparagraph_start); | |
771 | paragraph_start_re = Fsymbol_value (Qparagraph_start); | |
772 | if (!STRINGP (paragraph_start_re)) | |
773 | paragraph_start_re = build_string ("\f\\|[ \t]*$"); | |
774 | staticpro (¶graph_start_re); | |
775 | Qparagraph_separate = intern ("paragraph-separate"); | |
776 | staticpro (&Qparagraph_separate); | |
777 | paragraph_separate_re = Fsymbol_value (Qparagraph_separate); | |
778 | if (!STRINGP (paragraph_separate_re)) | |
779 | paragraph_separate_re = build_string ("[ \t\f]*$"); | |
780 | staticpro (¶graph_separate_re); | |
58b9f433 EZ |
781 | |
782 | bidi_cache_sp = 0; | |
ec7cc85b | 783 | bidi_cache_total_alloc = 0; |
58b9f433 | 784 | |
cbb09f04 | 785 | bidi_initialized = 1; |
b7b65b15 EZ |
786 | } |
787 | ||
cbb09f04 EZ |
788 | /* Do whatever UAX#9 clause X8 says should be done at paragraph's |
789 | end. */ | |
0a99eee1 | 790 | static void |
cbb09f04 | 791 | bidi_set_paragraph_end (struct bidi_it *bidi_it) |
b7b65b15 | 792 | { |
cbb09f04 EZ |
793 | bidi_it->invalid_levels = 0; |
794 | bidi_it->invalid_rl_levels = -1; | |
795 | bidi_it->stack_idx = 0; | |
796 | bidi_it->resolved_level = bidi_it->level_stack[0].level; | |
797 | } | |
b7b65b15 | 798 | |
cbb09f04 EZ |
799 | /* Initialize the bidi iterator from buffer/string position CHARPOS. */ |
800 | void | |
2cc21167 | 801 | bidi_init_it (ptrdiff_t charpos, ptrdiff_t bytepos, bool frame_window_p, |
cbb09f04 EZ |
802 | struct bidi_it *bidi_it) |
803 | { | |
804 | if (! bidi_initialized) | |
805 | bidi_initialize (); | |
806 | if (charpos >= 0) | |
807 | bidi_it->charpos = charpos; | |
808 | if (bytepos >= 0) | |
809 | bidi_it->bytepos = bytepos; | |
810 | bidi_it->frame_window_p = frame_window_p; | |
811 | bidi_it->nchars = -1; /* to be computed in bidi_resolve_explicit_1 */ | |
812 | bidi_it->first_elt = 1; | |
813 | bidi_set_paragraph_end (bidi_it); | |
814 | bidi_it->new_paragraph = 1; | |
815 | bidi_it->separator_limit = -1; | |
816 | bidi_it->type = NEUTRAL_B; | |
817 | bidi_it->type_after_w1 = NEUTRAL_B; | |
818 | bidi_it->orig_type = NEUTRAL_B; | |
819 | bidi_it->prev_was_pdf = 0; | |
512a289d RS |
820 | bidi_it->prev.type = bidi_it->prev.type_after_w1 |
821 | = bidi_it->prev.orig_type = UNKNOWN_BT; | |
822 | bidi_it->last_strong.type = bidi_it->last_strong.type_after_w1 | |
823 | = bidi_it->last_strong.orig_type = UNKNOWN_BT; | |
cbb09f04 | 824 | bidi_it->next_for_neutral.charpos = -1; |
512a289d RS |
825 | bidi_it->next_for_neutral.type |
826 | = bidi_it->next_for_neutral.type_after_w1 | |
827 | = bidi_it->next_for_neutral.orig_type = UNKNOWN_BT; | |
cbb09f04 | 828 | bidi_it->prev_for_neutral.charpos = -1; |
512a289d RS |
829 | bidi_it->prev_for_neutral.type |
830 | = bidi_it->prev_for_neutral.type_after_w1 | |
831 | = bidi_it->prev_for_neutral.orig_type = UNKNOWN_BT; | |
cbb09f04 EZ |
832 | bidi_it->sor = L2R; /* FIXME: should it be user-selectable? */ |
833 | bidi_it->disp_pos = -1; /* invalid/unknown */ | |
0c95fcf7 | 834 | bidi_it->disp_prop = 0; |
cbb09f04 EZ |
835 | /* We can only shrink the cache if we are at the bottom level of its |
836 | "stack". */ | |
837 | if (bidi_cache_start == 0) | |
838 | bidi_cache_shrink (); | |
58b9f433 EZ |
839 | else |
840 | bidi_cache_reset (); | |
b7b65b15 EZ |
841 | } |
842 | ||
182ce2d2 | 843 | /* Perform initializations for reordering a new line of bidi text. */ |
6bff6497 | 844 | static void |
be39f003 EZ |
845 | bidi_line_init (struct bidi_it *bidi_it) |
846 | { | |
847 | bidi_it->scan_dir = 1; /* FIXME: do we need to have control on this? */ | |
848 | bidi_it->resolved_level = bidi_it->level_stack[0].level; | |
849 | bidi_it->level_stack[0].override = NEUTRAL_DIR; /* X1 */ | |
850 | bidi_it->invalid_levels = 0; | |
851 | bidi_it->invalid_rl_levels = -1; | |
4787455f EZ |
852 | /* Setting this to zero will force its recomputation the first time |
853 | we need it for W5. */ | |
854 | bidi_it->next_en_pos = 0; | |
7b5d6677 | 855 | bidi_it->next_en_type = UNKNOWN_BT; |
be39f003 | 856 | bidi_it->next_for_ws.type = UNKNOWN_BT; |
b44d9321 | 857 | bidi_set_sor_type (bidi_it, |
512a289d | 858 | (bidi_it->paragraph_dir == R2L ? 1 : 0), |
be39f003 EZ |
859 | bidi_it->level_stack[0].level); /* X10 */ |
860 | ||
861 | bidi_cache_reset (); | |
862 | } | |
863 | ||
cbb09f04 EZ |
864 | \f |
865 | /*********************************************************************** | |
866 | Fetching characters | |
867 | ***********************************************************************/ | |
868 | ||
f3014ef5 EZ |
869 | /* Count bytes in string S between BEG/BEGBYTE and END. BEG and END |
870 | are zero-based character positions in S, BEGBYTE is byte position | |
2cc21167 | 871 | corresponding to BEG. UNIBYTE means S is a unibyte string. */ |
0a99eee1 | 872 | static ptrdiff_t |
d311d28c | 873 | bidi_count_bytes (const unsigned char *s, const ptrdiff_t beg, |
2cc21167 | 874 | const ptrdiff_t begbyte, const ptrdiff_t end, bool unibyte) |
87e67904 | 875 | { |
d311d28c | 876 | ptrdiff_t pos = beg; |
87e67904 EZ |
877 | const unsigned char *p = s + begbyte, *start = p; |
878 | ||
f3014ef5 EZ |
879 | if (unibyte) |
880 | p = s + end; | |
881 | else | |
87e67904 | 882 | { |
f3014ef5 | 883 | if (!CHAR_HEAD_P (*p)) |
1088b922 | 884 | emacs_abort (); |
f3014ef5 EZ |
885 | |
886 | while (pos < end) | |
887 | { | |
888 | p += BYTES_BY_CHAR_HEAD (*p); | |
889 | pos++; | |
890 | } | |
87e67904 EZ |
891 | } |
892 | ||
893 | return p - start; | |
894 | } | |
895 | ||
05584c31 | 896 | /* Fetch and return the character at byte position BYTEPOS. If S is |
87e67904 | 897 | non-NULL, fetch the character from string S; otherwise fetch the |
2cc21167 | 898 | character from the current buffer. UNIBYTE means S is a |
f3014ef5 | 899 | unibyte string. */ |
0a99eee1 | 900 | static int |
2cc21167 | 901 | bidi_char_at_pos (ptrdiff_t bytepos, const unsigned char *s, bool unibyte) |
87e67904 EZ |
902 | { |
903 | if (s) | |
f3014ef5 | 904 | { |
05584c31 | 905 | s += bytepos; |
f3014ef5 | 906 | if (unibyte) |
05584c31 | 907 | return *s; |
f3014ef5 | 908 | } |
87e67904 | 909 | else |
05584c31 PE |
910 | s = BYTE_POS_ADDR (bytepos); |
911 | return STRING_CHAR (s); | |
87e67904 EZ |
912 | } |
913 | ||
36075a19 | 914 | /* Fetch and return the character at CHARPOS/BYTEPOS. If that |
102ebb00 | 915 | character is covered by a display string, treat the entire run of |
0c95fcf7 EZ |
916 | covered characters as a single character, either u+2029 or u+FFFC, |
917 | and return their combined length in CH_LEN and NCHARS. DISP_POS | |
918 | specifies the character position of the next display string, or -1 | |
b75258b3 EZ |
919 | if not yet computed. When the next character is at or beyond that |
920 | position, the function updates DISP_POS with the position of the | |
2cc21167 | 921 | next display string. *DISP_PROP non-zero means that there's really |
0c95fcf7 | 922 | a display string at DISP_POS, as opposed to when we searched till |
2cc21167 | 923 | DISP_POS without finding one. If *DISP_PROP is 2, it means the |
0c95fcf7 | 924 | display spec is of the form `(space ...)', which is replaced with |
b75258b3 EZ |
925 | u+2029 to handle it as a paragraph separator. STRING->s is the C |
926 | string to iterate, or NULL if iterating over a buffer or a Lisp | |
927 | string; in the latter case, STRING->lstring is the Lisp string. */ | |
0a99eee1 | 928 | static int |
36075a19 | 929 | bidi_fetch_char (ptrdiff_t charpos, ptrdiff_t bytepos, ptrdiff_t *disp_pos, |
0c95fcf7 | 930 | int *disp_prop, struct bidi_string_data *string, |
5bf97bfc | 931 | struct window *w, |
2cc21167 | 932 | bool frame_window_p, ptrdiff_t *ch_len, ptrdiff_t *nchars) |
182ce2d2 EZ |
933 | { |
934 | int ch; | |
5895d7b9 | 935 | ptrdiff_t endpos |
512a289d | 936 | = (string->s || STRINGP (string->lstring)) ? string->schars : ZV; |
6db161be | 937 | struct text_pos pos; |
e99a9b8b | 938 | int len; |
182ce2d2 | 939 | |
182ce2d2 | 940 | /* If we got past the last known position of display string, compute |
87e67904 EZ |
941 | the position of the next one. That position could be at CHARPOS. */ |
942 | if (charpos < endpos && charpos > *disp_pos) | |
6db161be EZ |
943 | { |
944 | SET_TEXT_POS (pos, charpos, bytepos); | |
5bf97bfc | 945 | *disp_pos = compute_display_string_pos (&pos, string, w, frame_window_p, |
0c95fcf7 | 946 | disp_prop); |
6db161be | 947 | } |
102ebb00 EZ |
948 | |
949 | /* Fetch the character at BYTEPOS. */ | |
87e67904 | 950 | if (charpos >= endpos) |
182ce2d2 EZ |
951 | { |
952 | ch = BIDI_EOB; | |
953 | *ch_len = 1; | |
954 | *nchars = 1; | |
87e67904 | 955 | *disp_pos = endpos; |
0c95fcf7 | 956 | *disp_prop = 0; |
182ce2d2 | 957 | } |
0c95fcf7 | 958 | else if (charpos >= *disp_pos && *disp_prop) |
182ce2d2 | 959 | { |
d311d28c | 960 | ptrdiff_t disp_end_pos; |
7b600102 EZ |
961 | |
962 | /* We don't expect to find ourselves in the middle of a display | |
963 | property. Hopefully, it will never be needed. */ | |
964 | if (charpos > *disp_pos) | |
1088b922 | 965 | emacs_abort (); |
0c95fcf7 EZ |
966 | /* Text covered by `display' properties and overlays with |
967 | display properties or display strings is handled as a single | |
968 | character that represents the entire run of characters | |
969 | covered by the display property. */ | |
970 | if (*disp_prop == 2) | |
971 | { | |
972 | /* `(space ...)' display specs are handled as paragraph | |
973 | separators for the purposes of the reordering; see UAX#9 | |
974 | section 3 and clause HL1 in section 4.3 there. */ | |
975 | ch = 0x2029; | |
976 | } | |
977 | else | |
978 | { | |
979 | /* All other display specs are handled as the Unicode Object | |
980 | Replacement Character. */ | |
981 | ch = 0xFFFC; | |
982 | } | |
87e67904 | 983 | disp_end_pos = compute_display_string_end (*disp_pos, string); |
fbcaa2f3 EZ |
984 | if (disp_end_pos < 0) |
985 | { | |
986 | /* Somebody removed the display string from the buffer | |
987 | behind our back. Recover by processing this buffer | |
988 | position as if no display property were present there to | |
989 | begin with. */ | |
990 | *disp_prop = 0; | |
991 | goto normal_char; | |
992 | } | |
7b600102 | 993 | *nchars = disp_end_pos - *disp_pos; |
f3014ef5 | 994 | if (*nchars <= 0) |
1088b922 | 995 | emacs_abort (); |
87e67904 EZ |
996 | if (string->s) |
997 | *ch_len = bidi_count_bytes (string->s, *disp_pos, bytepos, | |
f3014ef5 | 998 | disp_end_pos, string->unibyte); |
9f257352 EZ |
999 | else if (STRINGP (string->lstring)) |
1000 | *ch_len = bidi_count_bytes (SDATA (string->lstring), *disp_pos, | |
f3014ef5 | 1001 | bytepos, disp_end_pos, string->unibyte); |
87e67904 EZ |
1002 | else |
1003 | *ch_len = CHAR_TO_BYTE (disp_end_pos) - bytepos; | |
182ce2d2 | 1004 | } |
182ce2d2 EZ |
1005 | else |
1006 | { | |
fbcaa2f3 | 1007 | normal_char: |
87e67904 EZ |
1008 | if (string->s) |
1009 | { | |
87e67904 | 1010 | |
f3014ef5 EZ |
1011 | if (!string->unibyte) |
1012 | { | |
1013 | ch = STRING_CHAR_AND_LENGTH (string->s + bytepos, len); | |
1014 | *ch_len = len; | |
1015 | } | |
1016 | else | |
1017 | { | |
1018 | ch = UNIBYTE_TO_CHAR (string->s[bytepos]); | |
1019 | *ch_len = 1; | |
1020 | } | |
87e67904 | 1021 | } |
9f257352 EZ |
1022 | else if (STRINGP (string->lstring)) |
1023 | { | |
f3014ef5 EZ |
1024 | if (!string->unibyte) |
1025 | { | |
1026 | ch = STRING_CHAR_AND_LENGTH (SDATA (string->lstring) + bytepos, | |
1027 | len); | |
1028 | *ch_len = len; | |
1029 | } | |
1030 | else | |
1031 | { | |
1032 | ch = UNIBYTE_TO_CHAR (SREF (string->lstring, bytepos)); | |
1033 | *ch_len = 1; | |
1034 | } | |
9f257352 | 1035 | } |
87e67904 EZ |
1036 | else |
1037 | { | |
e99a9b8b EZ |
1038 | ch = STRING_CHAR_AND_LENGTH (BYTE_POS_ADDR (bytepos), len); |
1039 | *ch_len = len; | |
87e67904 | 1040 | } |
182ce2d2 EZ |
1041 | *nchars = 1; |
1042 | } | |
1043 | ||
1044 | /* If we just entered a run of characters covered by a display | |
1045 | string, compute the position of the next display string. */ | |
55439c61 | 1046 | if (charpos + *nchars <= endpos && charpos + *nchars > *disp_pos |
0c95fcf7 | 1047 | && *disp_prop) |
6db161be EZ |
1048 | { |
1049 | SET_TEXT_POS (pos, charpos + *nchars, bytepos + *ch_len); | |
5bf97bfc | 1050 | *disp_pos = compute_display_string_pos (&pos, string, w, frame_window_p, |
0c95fcf7 | 1051 | disp_prop); |
6db161be | 1052 | } |
182ce2d2 EZ |
1053 | |
1054 | return ch; | |
1055 | } | |
1056 | ||
cbb09f04 EZ |
1057 | \f |
1058 | /*********************************************************************** | |
1059 | Determining paragraph direction | |
1060 | ***********************************************************************/ | |
1061 | ||
1062 | /* Check if buffer position CHARPOS/BYTEPOS is the end of a paragraph. | |
1063 | Value is the non-negative length of the paragraph separator | |
1064 | following the buffer position, -1 if position is at the beginning | |
1065 | of a new paragraph, or -2 if position is neither at beginning nor | |
1066 | at end of a paragraph. */ | |
d311d28c PE |
1067 | static ptrdiff_t |
1068 | bidi_at_paragraph_end (ptrdiff_t charpos, ptrdiff_t bytepos) | |
cbb09f04 EZ |
1069 | { |
1070 | Lisp_Object sep_re; | |
1071 | Lisp_Object start_re; | |
d311d28c | 1072 | ptrdiff_t val; |
cbb09f04 EZ |
1073 | |
1074 | sep_re = paragraph_separate_re; | |
1075 | start_re = paragraph_start_re; | |
1076 | ||
1077 | val = fast_looking_at (sep_re, charpos, bytepos, ZV, ZV_BYTE, Qnil); | |
1078 | if (val < 0) | |
1079 | { | |
1080 | if (fast_looking_at (start_re, charpos, bytepos, ZV, ZV_BYTE, Qnil) >= 0) | |
1081 | val = -1; | |
1082 | else | |
1083 | val = -2; | |
1084 | } | |
1085 | ||
1086 | return val; | |
1087 | } | |
1088 | ||
e30b79c1 DA |
1089 | /* If the user has requested the long scans caching, make sure that |
1090 | BIDI cache is enabled. Otherwise, make sure it's disabled. */ | |
1091 | ||
1092 | static struct region_cache * | |
1093 | bidi_paragraph_cache_on_off (void) | |
1094 | { | |
1095 | if (NILP (BVAR (current_buffer, cache_long_scans))) | |
1096 | { | |
1097 | if (current_buffer->bidi_paragraph_cache) | |
1098 | { | |
1099 | free_region_cache (current_buffer->bidi_paragraph_cache); | |
1100 | current_buffer->bidi_paragraph_cache = 0; | |
1101 | } | |
1102 | return NULL; | |
1103 | } | |
1104 | else | |
1105 | { | |
1106 | if (!current_buffer->bidi_paragraph_cache) | |
1107 | current_buffer->bidi_paragraph_cache = new_region_cache (); | |
1108 | return current_buffer->bidi_paragraph_cache; | |
1109 | } | |
1110 | } | |
1111 | ||
1137e8b8 EZ |
1112 | /* On my 2005-vintage machine, searching back for paragraph start |
1113 | takes ~1 ms per line. And bidi_paragraph_init is called 4 times | |
1114 | when user types C-p. The number below limits each call to | |
1115 | bidi_paragraph_init to about 10 ms. */ | |
1116 | #define MAX_PARAGRAPH_SEARCH 7500 | |
1117 | ||
be39f003 | 1118 | /* Find the beginning of this paragraph by looking back in the buffer. |
1137e8b8 EZ |
1119 | Value is the byte position of the paragraph's beginning, or |
1120 | BEGV_BYTE if paragraph_start_re is still not found after looking | |
1121 | back MAX_PARAGRAPH_SEARCH lines in the buffer. */ | |
d311d28c PE |
1122 | static ptrdiff_t |
1123 | bidi_find_paragraph_start (ptrdiff_t pos, ptrdiff_t pos_byte) | |
6bff6497 | 1124 | { |
372b7a95 | 1125 | Lisp_Object re = paragraph_start_re; |
d311d28c | 1126 | ptrdiff_t limit = ZV, limit_byte = ZV_BYTE; |
e30b79c1 DA |
1127 | struct region_cache *bpc = bidi_paragraph_cache_on_off (); |
1128 | ptrdiff_t n = 0, oldpos = pos, next; | |
6bff6497 | 1129 | |
6bff6497 | 1130 | while (pos_byte > BEGV_BYTE |
1137e8b8 | 1131 | && n++ < MAX_PARAGRAPH_SEARCH |
6bff6497 | 1132 | && fast_looking_at (re, pos, pos_byte, limit, limit_byte, Qnil) < 0) |
b5426561 DA |
1133 | { |
1134 | /* FIXME: What if the paragraph beginning is covered by a | |
1135 | display string? And what if a display string covering some | |
1136 | of the text over which we scan back includes | |
1137 | paragraph_start_re? */ | |
1138 | DEC_BOTH (pos, pos_byte); | |
e30b79c1 DA |
1139 | if (bpc && region_cache_backward (current_buffer, bpc, pos, &next)) |
1140 | { | |
1141 | pos = next, pos_byte = CHAR_TO_BYTE (pos); | |
1142 | break; | |
1143 | } | |
1144 | else | |
1145 | pos = find_newline_no_quit (pos, pos_byte, -1, &pos_byte); | |
b5426561 | 1146 | } |
1137e8b8 | 1147 | if (n >= MAX_PARAGRAPH_SEARCH) |
e30b79c1 DA |
1148 | pos = BEGV, pos_byte = BEGV_BYTE; |
1149 | if (bpc) | |
1150 | know_region_cache (current_buffer, bpc, pos, oldpos); | |
be39f003 | 1151 | return pos_byte; |
6bff6497 EZ |
1152 | } |
1153 | ||
ce811ad9 EZ |
1154 | /* On a 3.4 GHz machine, searching forward for a strong directional |
1155 | character in a long paragraph full of weaks or neutrals takes about | |
1156 | 1 ms for each 20K characters. The number below limits each call to | |
1157 | bidi_paragraph_init to less than 10 ms even on slow machines. */ | |
1158 | #define MAX_STRONG_CHAR_SEARCH 100000 | |
1159 | ||
bea4f10c | 1160 | /* Determine the base direction, a.k.a. base embedding level, of the |
b44d9321 EZ |
1161 | paragraph we are about to iterate through. If DIR is either L2R or |
1162 | R2L, just use that. Otherwise, determine the paragraph direction | |
bea4f10c EZ |
1163 | from the first strong directional character of the paragraph. |
1164 | ||
2cc21167 | 1165 | NO_DEFAULT_P means don't default to L2R if the paragraph |
bea4f10c EZ |
1166 | has no strong directional characters and both DIR and |
1167 | bidi_it->paragraph_dir are NEUTRAL_DIR. In that case, search back | |
1168 | in the buffer until a paragraph is found with a strong character, | |
1169 | or until hitting BEGV. In the latter case, fall back to L2R. This | |
1170 | flag is used in current-bidi-paragraph-direction. | |
1171 | ||
1172 | Note that this function gives the paragraph separator the same | |
1173 | direction as the preceding paragraph, even though Emacs generally | |
9858f6c3 | 1174 | views the separator as not belonging to any paragraph. */ |
b7b65b15 | 1175 | void |
2cc21167 | 1176 | bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, bool no_default_p) |
b7b65b15 | 1177 | { |
d311d28c | 1178 | ptrdiff_t bytepos = bidi_it->bytepos; |
2cc21167 | 1179 | bool string_p = bidi_it->string.s || STRINGP (bidi_it->string.lstring); |
d311d28c | 1180 | ptrdiff_t pstartbyte; |
87e67904 EZ |
1181 | /* Note that begbyte is a byte position, while end is a character |
1182 | position. Yes, this is ugly, but we are trying to avoid costly | |
1183 | calls to BYTE_TO_CHAR and its ilk. */ | |
d311d28c PE |
1184 | ptrdiff_t begbyte = string_p ? 0 : BEGV_BYTE; |
1185 | ptrdiff_t end = string_p ? bidi_it->string.schars : ZV; | |
e7402cb2 | 1186 | |
5e65aec0 | 1187 | /* Special case for an empty buffer. */ |
87e67904 | 1188 | if (bytepos == begbyte && bidi_it->charpos == end) |
5e65aec0 | 1189 | dir = L2R; |
9c82e145 | 1190 | /* We should never be called at EOB or before BEGV. */ |
87e67904 | 1191 | else if (bidi_it->charpos >= end || bytepos < begbyte) |
1088b922 | 1192 | emacs_abort (); |
9c82e145 | 1193 | |
be39f003 EZ |
1194 | if (dir == L2R) |
1195 | { | |
1196 | bidi_it->paragraph_dir = L2R; | |
1197 | bidi_it->new_paragraph = 0; | |
1198 | } | |
1199 | else if (dir == R2L) | |
1200 | { | |
1201 | bidi_it->paragraph_dir = R2L; | |
1202 | bidi_it->new_paragraph = 0; | |
1203 | } | |
b7b65b15 EZ |
1204 | else if (dir == NEUTRAL_DIR) /* P2 */ |
1205 | { | |
182ce2d2 | 1206 | int ch; |
d311d28c PE |
1207 | ptrdiff_t ch_len, nchars; |
1208 | ptrdiff_t pos, disp_pos = -1; | |
0c95fcf7 | 1209 | int disp_prop = 0; |
6bff6497 | 1210 | bidi_type_t type; |
9f257352 | 1211 | const unsigned char *s; |
be39f003 | 1212 | |
d20e1419 EZ |
1213 | if (!bidi_initialized) |
1214 | bidi_initialize (); | |
1215 | ||
be39f003 EZ |
1216 | /* If we are inside a paragraph separator, we are just waiting |
1217 | for the separator to be exhausted; use the previous paragraph | |
e5a2fec7 EZ |
1218 | direction. But don't do that if we have been just reseated, |
1219 | because we need to reinitialize below in that case. */ | |
1220 | if (!bidi_it->first_elt | |
1221 | && bidi_it->charpos < bidi_it->separator_limit) | |
be39f003 EZ |
1222 | return; |
1223 | ||
b44d9321 | 1224 | /* If we are on a newline, get past it to where the next |
5e65aec0 EZ |
1225 | paragraph might start. But don't do that at BEGV since then |
1226 | we are potentially in a new paragraph that doesn't yet | |
1227 | exist. */ | |
c143c213 | 1228 | pos = bidi_it->charpos; |
512a289d RS |
1229 | s = (STRINGP (bidi_it->string.lstring) |
1230 | ? SDATA (bidi_it->string.lstring) | |
1231 | : bidi_it->string.s); | |
f3014ef5 EZ |
1232 | if (bytepos > begbyte |
1233 | && bidi_char_at_pos (bytepos, s, bidi_it->string.unibyte) == '\n') | |
be39f003 | 1234 | { |
b44d9321 | 1235 | bytepos++; |
c143c213 | 1236 | pos++; |
be39f003 | 1237 | } |
b44d9321 EZ |
1238 | |
1239 | /* We are either at the beginning of a paragraph or in the | |
1240 | middle of it. Find where this paragraph starts. */ | |
87e67904 EZ |
1241 | if (string_p) |
1242 | { | |
1243 | /* We don't support changes of paragraph direction inside a | |
1244 | string. It is treated as a single paragraph. */ | |
1245 | pstartbyte = 0; | |
1246 | } | |
1247 | else | |
1248 | pstartbyte = bidi_find_paragraph_start (pos, bytepos); | |
be39f003 EZ |
1249 | bidi_it->separator_limit = -1; |
1250 | bidi_it->new_paragraph = 0; | |
bea4f10c | 1251 | |
2cc21167 PE |
1252 | /* The following loop is run more than once only if NO_DEFAULT_P, |
1253 | and only if we are iterating on a buffer. */ | |
bea4f10c | 1254 | do { |
ce811ad9 EZ |
1255 | ptrdiff_t pos1; |
1256 | ||
bea4f10c | 1257 | bytepos = pstartbyte; |
87e67904 EZ |
1258 | if (!string_p) |
1259 | pos = BYTE_TO_CHAR (bytepos); | |
36075a19 | 1260 | ch = bidi_fetch_char (pos, bytepos, &disp_pos, &disp_prop, |
5bf97bfc | 1261 | &bidi_it->string, bidi_it->w, |
87e67904 | 1262 | bidi_it->frame_window_p, &ch_len, &nchars); |
bea4f10c EZ |
1263 | type = bidi_get_type (ch, NEUTRAL_DIR); |
1264 | ||
ce811ad9 | 1265 | pos1 = pos; |
182ce2d2 | 1266 | for (pos += nchars, bytepos += ch_len; |
ce811ad9 EZ |
1267 | ((bidi_get_category (type) != STRONG) |
1268 | || (bidi_ignore_explicit_marks_for_paragraph_level | |
1269 | && (type == RLE || type == RLO | |
1270 | || type == LRE || type == LRO))) | |
1271 | /* Stop when searched too far into an abnormally large | |
1272 | paragraph full of weak or neutral characters. */ | |
1273 | && pos - pos1 < MAX_STRONG_CHAR_SEARCH; | |
bea4f10c EZ |
1274 | type = bidi_get_type (ch, NEUTRAL_DIR)) |
1275 | { | |
87e67904 | 1276 | if (pos >= end) |
bea4f10c EZ |
1277 | { |
1278 | /* Pretend there's a paragraph separator at end of | |
87e67904 | 1279 | buffer/string. */ |
bea4f10c EZ |
1280 | type = NEUTRAL_B; |
1281 | break; | |
1282 | } | |
0bb23927 EZ |
1283 | if (!string_p |
1284 | && type == NEUTRAL_B | |
1285 | && bidi_at_paragraph_end (pos, bytepos) >= -1) | |
cf99dcf8 | 1286 | break; |
102ebb00 | 1287 | /* Fetch next character and advance to get past it. */ |
36075a19 | 1288 | ch = bidi_fetch_char (pos, bytepos, &disp_pos, |
5bf97bfc | 1289 | &disp_prop, &bidi_it->string, bidi_it->w, |
fc6f18ce | 1290 | bidi_it->frame_window_p, &ch_len, &nchars); |
182ce2d2 EZ |
1291 | pos += nchars; |
1292 | bytepos += ch_len; | |
bea4f10c | 1293 | } |
32413314 EZ |
1294 | if ((type == STRONG_R || type == STRONG_AL) /* P3 */ |
1295 | || (!bidi_ignore_explicit_marks_for_paragraph_level | |
1296 | && (type == RLO || type == RLE))) | |
bea4f10c | 1297 | bidi_it->paragraph_dir = R2L; |
32413314 EZ |
1298 | else if (type == STRONG_L |
1299 | || (!bidi_ignore_explicit_marks_for_paragraph_level | |
1300 | && (type == LRO || type == LRE))) | |
bea4f10c | 1301 | bidi_it->paragraph_dir = L2R; |
87e67904 EZ |
1302 | if (!string_p |
1303 | && no_default_p && bidi_it->paragraph_dir == NEUTRAL_DIR) | |
bea4f10c EZ |
1304 | { |
1305 | /* If this paragraph is at BEGV, default to L2R. */ | |
1306 | if (pstartbyte == BEGV_BYTE) | |
1307 | bidi_it->paragraph_dir = L2R; /* P3 and HL1 */ | |
1308 | else | |
1309 | { | |
d311d28c PE |
1310 | ptrdiff_t prevpbyte = pstartbyte; |
1311 | ptrdiff_t p = BYTE_TO_CHAR (pstartbyte), pbyte = pstartbyte; | |
bea4f10c EZ |
1312 | |
1313 | /* Find the beginning of the previous paragraph, if any. */ | |
1314 | while (pbyte > BEGV_BYTE && prevpbyte >= pstartbyte) | |
1315 | { | |
182ce2d2 EZ |
1316 | /* FXIME: What if p is covered by a display |
1317 | string? See also a FIXME inside | |
1318 | bidi_find_paragraph_start. */ | |
36075a19 | 1319 | DEC_BOTH (p, pbyte); |
bea4f10c EZ |
1320 | prevpbyte = bidi_find_paragraph_start (p, pbyte); |
1321 | } | |
1322 | pstartbyte = prevpbyte; | |
1323 | } | |
1324 | } | |
87e67904 EZ |
1325 | } while (!string_p |
1326 | && no_default_p && bidi_it->paragraph_dir == NEUTRAL_DIR); | |
b7b65b15 | 1327 | } |
be39f003 | 1328 | else |
1088b922 | 1329 | emacs_abort (); |
b7b65b15 | 1330 | |
b44d9321 EZ |
1331 | /* Contrary to UAX#9 clause P3, we only default the paragraph |
1332 | direction to L2R if we have no previous usable paragraph | |
bea4f10c | 1333 | direction. This is allowed by the HL1 clause. */ |
d20e1419 | 1334 | if (bidi_it->paragraph_dir != L2R && bidi_it->paragraph_dir != R2L) |
bea4f10c | 1335 | bidi_it->paragraph_dir = L2R; /* P3 and HL1 ``higher-level protocols'' */ |
be39f003 | 1336 | if (bidi_it->paragraph_dir == R2L) |
b44d9321 | 1337 | bidi_it->level_stack[0].level = 1; |
be39f003 | 1338 | else |
b44d9321 | 1339 | bidi_it->level_stack[0].level = 0; |
be39f003 EZ |
1340 | |
1341 | bidi_line_init (bidi_it); | |
b7b65b15 EZ |
1342 | } |
1343 | ||
cbb09f04 EZ |
1344 | \f |
1345 | /*********************************************************************** | |
1346 | Resolving explicit and implicit levels. | |
58b9f433 | 1347 | The rest of this file constitutes the core of the UBA implementation. |
cbb09f04 | 1348 | ***********************************************************************/ |
b7b65b15 | 1349 | |
0a99eee1 | 1350 | static bool |
182ce2d2 | 1351 | bidi_explicit_dir_char (int ch) |
b7b65b15 | 1352 | { |
182ce2d2 EZ |
1353 | bidi_type_t ch_type; |
1354 | ||
1355 | if (!bidi_initialized) | |
1088b922 | 1356 | emacs_abort (); |
182ce2d2 EZ |
1357 | ch_type = (bidi_type_t) XINT (CHAR_TABLE_REF (bidi_type_table, ch)); |
1358 | return (ch_type == LRE || ch_type == LRO | |
1359 | || ch_type == RLE || ch_type == RLO | |
1360 | || ch_type == PDF); | |
b7b65b15 EZ |
1361 | } |
1362 | ||
1363 | /* A helper function for bidi_resolve_explicit. It advances to the | |
1364 | next character in logical order and determines the new embedding | |
1365 | level and directional override, but does not take into account | |
1366 | empty embeddings. */ | |
1367 | static int | |
1368 | bidi_resolve_explicit_1 (struct bidi_it *bidi_it) | |
1369 | { | |
1370 | int curchar; | |
1371 | bidi_type_t type; | |
1372 | int current_level; | |
1373 | int new_level; | |
1374 | bidi_dir_t override; | |
2cc21167 | 1375 | bool string_p = bidi_it->string.s || STRINGP (bidi_it->string.lstring); |
b7b65b15 | 1376 | |
182ce2d2 EZ |
1377 | /* If reseat()'ed, don't advance, so as to start iteration from the |
1378 | position where we were reseated. bidi_it->bytepos can be less | |
1379 | than BEGV_BYTE after reseat to BEGV. */ | |
87e67904 | 1380 | if (bidi_it->bytepos < (string_p ? 0 : BEGV_BYTE) |
9c82e145 | 1381 | || bidi_it->first_elt) |
e7402cb2 | 1382 | { |
9c82e145 | 1383 | bidi_it->first_elt = 0; |
87e67904 EZ |
1384 | if (string_p) |
1385 | { | |
512a289d RS |
1386 | const unsigned char *p |
1387 | = (STRINGP (bidi_it->string.lstring) | |
1388 | ? SDATA (bidi_it->string.lstring) | |
1389 | : bidi_it->string.s); | |
9f257352 | 1390 | |
87e67904 | 1391 | if (bidi_it->charpos < 0) |
05e193f1 EZ |
1392 | bidi_it->charpos = bidi_it->bytepos = 0; |
1393 | eassert (bidi_it->bytepos == bidi_count_bytes (p, 0, 0, | |
1394 | bidi_it->charpos, | |
1395 | bidi_it->string.unibyte)); | |
87e67904 EZ |
1396 | } |
1397 | else | |
1398 | { | |
1399 | if (bidi_it->charpos < BEGV) | |
05e193f1 EZ |
1400 | { |
1401 | bidi_it->charpos = BEGV; | |
1402 | bidi_it->bytepos = BEGV_BYTE; | |
1403 | } | |
1404 | eassert (bidi_it->bytepos == CHAR_TO_BYTE (bidi_it->charpos)); | |
87e67904 | 1405 | } |
e7402cb2 | 1406 | } |
87e67904 EZ |
1407 | /* Don't move at end of buffer/string. */ |
1408 | else if (bidi_it->charpos < (string_p ? bidi_it->string.schars : ZV)) | |
b7b65b15 | 1409 | { |
182ce2d2 EZ |
1410 | /* Advance to the next character, skipping characters covered by |
1411 | display strings (nchars > 1). */ | |
102ebb00 | 1412 | if (bidi_it->nchars <= 0) |
1088b922 | 1413 | emacs_abort (); |
182ce2d2 | 1414 | bidi_it->charpos += bidi_it->nchars; |
e7402cb2 | 1415 | if (bidi_it->ch_len == 0) |
1088b922 | 1416 | emacs_abort (); |
b7b65b15 EZ |
1417 | bidi_it->bytepos += bidi_it->ch_len; |
1418 | } | |
1419 | ||
1420 | current_level = bidi_it->level_stack[bidi_it->stack_idx].level; /* X1 */ | |
1421 | override = bidi_it->level_stack[bidi_it->stack_idx].override; | |
1422 | new_level = current_level; | |
1423 | ||
87e67904 | 1424 | if (bidi_it->charpos >= (string_p ? bidi_it->string.schars : ZV)) |
e7402cb2 EZ |
1425 | { |
1426 | curchar = BIDI_EOB; | |
1427 | bidi_it->ch_len = 1; | |
182ce2d2 | 1428 | bidi_it->nchars = 1; |
87e67904 | 1429 | bidi_it->disp_pos = (string_p ? bidi_it->string.schars : ZV); |
0c95fcf7 | 1430 | bidi_it->disp_prop = 0; |
e7402cb2 EZ |
1431 | } |
1432 | else | |
1433 | { | |
182ce2d2 EZ |
1434 | /* Fetch the character at BYTEPOS. If it is covered by a |
1435 | display string, treat the entire run of covered characters as | |
1436 | a single character u+FFFC. */ | |
36075a19 | 1437 | curchar = bidi_fetch_char (bidi_it->charpos, bidi_it->bytepos, |
0c95fcf7 | 1438 | &bidi_it->disp_pos, &bidi_it->disp_prop, |
5bf97bfc EZ |
1439 | &bidi_it->string, bidi_it->w, |
1440 | bidi_it->frame_window_p, | |
102ebb00 | 1441 | &bidi_it->ch_len, &bidi_it->nchars); |
e7402cb2 | 1442 | } |
b7b65b15 | 1443 | bidi_it->ch = curchar; |
b7b65b15 | 1444 | |
6bff6497 EZ |
1445 | /* Don't apply directional override here, as all the types we handle |
1446 | below will not be affected by the override anyway, and we need | |
1447 | the original type unaltered. The override will be applied in | |
1448 | bidi_resolve_weak. */ | |
1449 | type = bidi_get_type (curchar, NEUTRAL_DIR); | |
89d3374a EZ |
1450 | bidi_it->orig_type = type; |
1451 | bidi_check_type (bidi_it->orig_type); | |
b7b65b15 EZ |
1452 | |
1453 | if (type != PDF) | |
1454 | bidi_it->prev_was_pdf = 0; | |
1455 | ||
89d3374a | 1456 | bidi_it->type_after_w1 = UNKNOWN_BT; |
b7b65b15 EZ |
1457 | |
1458 | switch (type) | |
1459 | { | |
1460 | case RLE: /* X2 */ | |
1461 | case RLO: /* X4 */ | |
89d3374a EZ |
1462 | bidi_it->type_after_w1 = type; |
1463 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 | 1464 | type = WEAK_BN; /* X9/Retaining */ |
87e67904 | 1465 | if (bidi_it->ignore_bn_limit <= -1) |
b7b65b15 EZ |
1466 | { |
1467 | if (current_level <= BIDI_MAXLEVEL - 4) | |
1468 | { | |
1469 | /* Compute the least odd embedding level greater than | |
1470 | the current level. */ | |
1471 | new_level = ((current_level + 1) & ~1) + 1; | |
89d3374a | 1472 | if (bidi_it->type_after_w1 == RLE) |
b7b65b15 EZ |
1473 | override = NEUTRAL_DIR; |
1474 | else | |
1475 | override = R2L; | |
1476 | if (current_level == BIDI_MAXLEVEL - 4) | |
1477 | bidi_it->invalid_rl_levels = 0; | |
1478 | bidi_push_embedding_level (bidi_it, new_level, override); | |
1479 | } | |
1480 | else | |
1481 | { | |
1482 | bidi_it->invalid_levels++; | |
1483 | /* See the commentary about invalid_rl_levels below. */ | |
1484 | if (bidi_it->invalid_rl_levels < 0) | |
1485 | bidi_it->invalid_rl_levels = 0; | |
1486 | bidi_it->invalid_rl_levels++; | |
1487 | } | |
1488 | } | |
89d3374a | 1489 | else if (bidi_it->prev.type_after_w1 == WEAK_EN /* W5/Retaining */ |
7b5d6677 EZ |
1490 | || (bidi_it->next_en_pos > bidi_it->charpos |
1491 | && bidi_it->next_en_type == WEAK_EN)) | |
b7b65b15 EZ |
1492 | type = WEAK_EN; |
1493 | break; | |
1494 | case LRE: /* X3 */ | |
1495 | case LRO: /* X5 */ | |
89d3374a EZ |
1496 | bidi_it->type_after_w1 = type; |
1497 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 | 1498 | type = WEAK_BN; /* X9/Retaining */ |
87e67904 | 1499 | if (bidi_it->ignore_bn_limit <= -1) |
b7b65b15 EZ |
1500 | { |
1501 | if (current_level <= BIDI_MAXLEVEL - 5) | |
1502 | { | |
1503 | /* Compute the least even embedding level greater than | |
1504 | the current level. */ | |
1505 | new_level = ((current_level + 2) & ~1); | |
89d3374a | 1506 | if (bidi_it->type_after_w1 == LRE) |
b7b65b15 EZ |
1507 | override = NEUTRAL_DIR; |
1508 | else | |
1509 | override = L2R; | |
1510 | bidi_push_embedding_level (bidi_it, new_level, override); | |
1511 | } | |
1512 | else | |
1513 | { | |
1514 | bidi_it->invalid_levels++; | |
1515 | /* invalid_rl_levels counts invalid levels encountered | |
1516 | while the embedding level was already too high for | |
1517 | LRE/LRO, but not for RLE/RLO. That is because | |
1518 | there may be exactly one PDF which we should not | |
1519 | ignore even though invalid_levels is non-zero. | |
1520 | invalid_rl_levels helps to know what PDF is | |
1521 | that. */ | |
1522 | if (bidi_it->invalid_rl_levels >= 0) | |
1523 | bidi_it->invalid_rl_levels++; | |
1524 | } | |
1525 | } | |
89d3374a | 1526 | else if (bidi_it->prev.type_after_w1 == WEAK_EN /* W5/Retaining */ |
7b5d6677 EZ |
1527 | || (bidi_it->next_en_pos > bidi_it->charpos |
1528 | && bidi_it->next_en_type == WEAK_EN)) | |
b7b65b15 EZ |
1529 | type = WEAK_EN; |
1530 | break; | |
1531 | case PDF: /* X7 */ | |
89d3374a EZ |
1532 | bidi_it->type_after_w1 = type; |
1533 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 | 1534 | type = WEAK_BN; /* X9/Retaining */ |
87e67904 | 1535 | if (bidi_it->ignore_bn_limit <= -1) |
b7b65b15 EZ |
1536 | { |
1537 | if (!bidi_it->invalid_rl_levels) | |
1538 | { | |
1539 | new_level = bidi_pop_embedding_level (bidi_it); | |
1540 | bidi_it->invalid_rl_levels = -1; | |
1541 | if (bidi_it->invalid_levels) | |
1542 | bidi_it->invalid_levels--; | |
1543 | /* else nothing: UAX#9 says to ignore invalid PDFs */ | |
1544 | } | |
1545 | if (!bidi_it->invalid_levels) | |
1546 | new_level = bidi_pop_embedding_level (bidi_it); | |
1547 | else | |
1548 | { | |
1549 | bidi_it->invalid_levels--; | |
1550 | bidi_it->invalid_rl_levels--; | |
1551 | } | |
1552 | } | |
89d3374a | 1553 | else if (bidi_it->prev.type_after_w1 == WEAK_EN /* W5/Retaining */ |
7b5d6677 EZ |
1554 | || (bidi_it->next_en_pos > bidi_it->charpos |
1555 | && bidi_it->next_en_type == WEAK_EN)) | |
b7b65b15 EZ |
1556 | type = WEAK_EN; |
1557 | break; | |
1558 | default: | |
1559 | /* Nothing. */ | |
1560 | break; | |
1561 | } | |
1562 | ||
1563 | bidi_it->type = type; | |
2d6e4628 | 1564 | bidi_check_type (bidi_it->type); |
b7b65b15 EZ |
1565 | |
1566 | return new_level; | |
1567 | } | |
1568 | ||
1569 | /* Given an iterator state in BIDI_IT, advance one character position | |
182ce2d2 EZ |
1570 | in the buffer/string to the next character (in the logical order), |
1571 | resolve any explicit embeddings and directional overrides, and | |
1572 | return the embedding level of the character after resolving | |
1573 | explicit directives and ignoring empty embeddings. */ | |
b7b65b15 EZ |
1574 | static int |
1575 | bidi_resolve_explicit (struct bidi_it *bidi_it) | |
1576 | { | |
1577 | int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level; | |
1578 | int new_level = bidi_resolve_explicit_1 (bidi_it); | |
d311d28c | 1579 | ptrdiff_t eob = bidi_it->string.s ? bidi_it->string.schars : ZV; |
512a289d RS |
1580 | const unsigned char *s |
1581 | = (STRINGP (bidi_it->string.lstring) | |
1582 | ? SDATA (bidi_it->string.lstring) | |
1583 | : bidi_it->string.s); | |
b7b65b15 EZ |
1584 | |
1585 | if (prev_level < new_level | |
1586 | && bidi_it->type == WEAK_BN | |
87e67904 EZ |
1587 | && bidi_it->ignore_bn_limit == -1 /* only if not already known */ |
1588 | && bidi_it->charpos < eob /* not already at EOB */ | |
1589 | && bidi_explicit_dir_char (bidi_char_at_pos (bidi_it->bytepos | |
f3014ef5 EZ |
1590 | + bidi_it->ch_len, s, |
1591 | bidi_it->string.unibyte))) | |
b7b65b15 EZ |
1592 | { |
1593 | /* Avoid pushing and popping embedding levels if the level run | |
1594 | is empty, as this breaks level runs where it shouldn't. | |
1595 | UAX#9 removes all the explicit embedding and override codes, | |
1596 | so empty embeddings disappear without a trace. We need to | |
1597 | behave as if we did the same. */ | |
1598 | struct bidi_it saved_it; | |
1599 | int level = prev_level; | |
1600 | ||
1601 | bidi_copy_it (&saved_it, bidi_it); | |
1602 | ||
87e67904 | 1603 | while (bidi_explicit_dir_char (bidi_char_at_pos (bidi_it->bytepos |
f3014ef5 EZ |
1604 | + bidi_it->ch_len, s, |
1605 | bidi_it->string.unibyte))) | |
b7b65b15 | 1606 | { |
182ce2d2 EZ |
1607 | /* This advances to the next character, skipping any |
1608 | characters covered by display strings. */ | |
b7b65b15 | 1609 | level = bidi_resolve_explicit_1 (bidi_it); |
9f257352 EZ |
1610 | /* If string.lstring was relocated inside bidi_resolve_explicit_1, |
1611 | a pointer to its data is no longer valid. */ | |
1612 | if (STRINGP (bidi_it->string.lstring)) | |
1613 | s = SDATA (bidi_it->string.lstring); | |
b7b65b15 EZ |
1614 | } |
1615 | ||
102ebb00 | 1616 | if (bidi_it->nchars <= 0) |
1088b922 | 1617 | emacs_abort (); |
b7b65b15 | 1618 | if (level == prev_level) /* empty embedding */ |
182ce2d2 | 1619 | saved_it.ignore_bn_limit = bidi_it->charpos + bidi_it->nchars; |
b7b65b15 | 1620 | else /* this embedding is non-empty */ |
87e67904 | 1621 | saved_it.ignore_bn_limit = -2; |
b7b65b15 EZ |
1622 | |
1623 | bidi_copy_it (bidi_it, &saved_it); | |
87e67904 | 1624 | if (bidi_it->ignore_bn_limit > -1) |
b7b65b15 EZ |
1625 | { |
1626 | /* We pushed a level, but we shouldn't have. Undo that. */ | |
1627 | if (!bidi_it->invalid_rl_levels) | |
1628 | { | |
1629 | new_level = bidi_pop_embedding_level (bidi_it); | |
1630 | bidi_it->invalid_rl_levels = -1; | |
1631 | if (bidi_it->invalid_levels) | |
1632 | bidi_it->invalid_levels--; | |
1633 | } | |
1634 | if (!bidi_it->invalid_levels) | |
1635 | new_level = bidi_pop_embedding_level (bidi_it); | |
1636 | else | |
1637 | { | |
1638 | bidi_it->invalid_levels--; | |
1639 | bidi_it->invalid_rl_levels--; | |
1640 | } | |
1641 | } | |
1642 | } | |
1643 | ||
b7b65b15 EZ |
1644 | if (bidi_it->type == NEUTRAL_B) /* X8 */ |
1645 | { | |
21fce5ab | 1646 | bidi_set_paragraph_end (bidi_it); |
6bff6497 EZ |
1647 | /* This is needed by bidi_resolve_weak below, and in L1. */ |
1648 | bidi_it->type_after_w1 = bidi_it->type; | |
89d3374a | 1649 | bidi_check_type (bidi_it->type_after_w1); |
b7b65b15 EZ |
1650 | } |
1651 | ||
1652 | return new_level; | |
1653 | } | |
1654 | ||
182ce2d2 EZ |
1655 | /* Advance in the buffer/string, resolve weak types and return the |
1656 | type of the next character after weak type resolution. */ | |
fd3998ff | 1657 | static bidi_type_t |
b7b65b15 EZ |
1658 | bidi_resolve_weak (struct bidi_it *bidi_it) |
1659 | { | |
1660 | bidi_type_t type; | |
1661 | bidi_dir_t override; | |
1662 | int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level; | |
1663 | int new_level = bidi_resolve_explicit (bidi_it); | |
1664 | int next_char; | |
1665 | bidi_type_t type_of_next; | |
1666 | struct bidi_it saved_it; | |
5895d7b9 | 1667 | ptrdiff_t eob |
512a289d RS |
1668 | = ((STRINGP (bidi_it->string.lstring) || bidi_it->string.s) |
1669 | ? bidi_it->string.schars : ZV); | |
b7b65b15 EZ |
1670 | |
1671 | type = bidi_it->type; | |
1672 | override = bidi_it->level_stack[bidi_it->stack_idx].override; | |
1673 | ||
1674 | if (type == UNKNOWN_BT | |
1675 | || type == LRE | |
1676 | || type == LRO | |
1677 | || type == RLE | |
1678 | || type == RLO | |
1679 | || type == PDF) | |
1088b922 | 1680 | emacs_abort (); |
b7b65b15 EZ |
1681 | |
1682 | if (new_level != prev_level | |
1683 | || bidi_it->type == NEUTRAL_B) | |
1684 | { | |
1685 | /* We've got a new embedding level run, compute the directional | |
1686 | type of sor and initialize per-run variables (UAX#9, clause | |
1687 | X10). */ | |
1688 | bidi_set_sor_type (bidi_it, prev_level, new_level); | |
1689 | } | |
1690 | else if (type == NEUTRAL_S || type == NEUTRAL_WS | |
1691 | || type == WEAK_BN || type == STRONG_AL) | |
89d3374a EZ |
1692 | bidi_it->type_after_w1 = type; /* needed in L1 */ |
1693 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 EZ |
1694 | |
1695 | /* Level and directional override status are already recorded in | |
1696 | bidi_it, and do not need any change; see X6. */ | |
1697 | if (override == R2L) /* X6 */ | |
1698 | type = STRONG_R; | |
1699 | else if (override == L2R) | |
1700 | type = STRONG_L; | |
bc5a45f3 | 1701 | else |
b7b65b15 | 1702 | { |
bc5a45f3 | 1703 | if (type == WEAK_NSM) /* W1 */ |
b7b65b15 | 1704 | { |
bc5a45f3 | 1705 | /* Note that we don't need to consider the case where the |
5930fe97 EZ |
1706 | prev character has its type overridden by an RLO or LRO, |
1707 | because then either the type of this NSM would have been | |
1708 | also overridden, or the previous character is outside the | |
1709 | current level run, and thus not relevant to this NSM. | |
1710 | This is why NSM gets the type_after_w1 of the previous | |
1711 | character. */ | |
ebb5722e EZ |
1712 | if (bidi_it->prev.type_after_w1 != UNKNOWN_BT |
1713 | /* if type_after_w1 is NEUTRAL_B, this NSM is at sor */ | |
1714 | && bidi_it->prev.type_after_w1 != NEUTRAL_B) | |
5930fe97 | 1715 | type = bidi_it->prev.type_after_w1; |
bc5a45f3 EZ |
1716 | else if (bidi_it->sor == R2L) |
1717 | type = STRONG_R; | |
1718 | else if (bidi_it->sor == L2R) | |
1719 | type = STRONG_L; | |
1720 | else /* shouldn't happen! */ | |
1088b922 | 1721 | emacs_abort (); |
b7b65b15 | 1722 | } |
bc5a45f3 EZ |
1723 | if (type == WEAK_EN /* W2 */ |
1724 | && bidi_it->last_strong.type_after_w1 == STRONG_AL) | |
1725 | type = WEAK_AN; | |
1726 | else if (type == STRONG_AL) /* W3 */ | |
1727 | type = STRONG_R; | |
1728 | else if ((type == WEAK_ES /* W4 */ | |
1729 | && bidi_it->prev.type_after_w1 == WEAK_EN | |
1730 | && bidi_it->prev.orig_type == WEAK_EN) | |
1731 | || (type == WEAK_CS | |
1732 | && ((bidi_it->prev.type_after_w1 == WEAK_EN | |
1733 | && bidi_it->prev.orig_type == WEAK_EN) | |
1734 | || bidi_it->prev.type_after_w1 == WEAK_AN))) | |
b7b65b15 | 1735 | { |
512a289d RS |
1736 | const unsigned char *s |
1737 | = (STRINGP (bidi_it->string.lstring) | |
1738 | ? SDATA (bidi_it->string.lstring) | |
1739 | : bidi_it->string.s); | |
1740 | ||
1741 | next_char = (bidi_it->charpos + bidi_it->nchars >= eob | |
1742 | ? BIDI_EOB | |
1743 | : bidi_char_at_pos (bidi_it->bytepos + bidi_it->ch_len, | |
1744 | s, bidi_it->string.unibyte)); | |
6bff6497 | 1745 | type_of_next = bidi_get_type (next_char, override); |
b7b65b15 | 1746 | |
bc5a45f3 | 1747 | if (type_of_next == WEAK_BN |
b7b65b15 EZ |
1748 | || bidi_explicit_dir_char (next_char)) |
1749 | { | |
1750 | bidi_copy_it (&saved_it, bidi_it); | |
1751 | while (bidi_resolve_explicit (bidi_it) == new_level | |
bc5a45f3 | 1752 | && bidi_it->type == WEAK_BN) |
b7b65b15 EZ |
1753 | ; |
1754 | type_of_next = bidi_it->type; | |
b7b65b15 EZ |
1755 | bidi_copy_it (bidi_it, &saved_it); |
1756 | } | |
bc5a45f3 EZ |
1757 | |
1758 | /* If the next character is EN, but the last strong-type | |
1759 | character is AL, that next EN will be changed to AN when | |
1760 | we process it in W2 above. So in that case, this ES | |
1761 | should not be changed into EN. */ | |
1762 | if (type == WEAK_ES | |
1763 | && type_of_next == WEAK_EN | |
1764 | && bidi_it->last_strong.type_after_w1 != STRONG_AL) | |
1765 | type = WEAK_EN; | |
1766 | else if (type == WEAK_CS) | |
b7b65b15 | 1767 | { |
bc5a45f3 EZ |
1768 | if (bidi_it->prev.type_after_w1 == WEAK_AN |
1769 | && (type_of_next == WEAK_AN | |
1770 | /* If the next character is EN, but the last | |
1771 | strong-type character is AL, EN will be later | |
1772 | changed to AN when we process it in W2 above. | |
1773 | So in that case, this ES should not be | |
1774 | changed into EN. */ | |
1775 | || (type_of_next == WEAK_EN | |
1776 | && bidi_it->last_strong.type_after_w1 == STRONG_AL))) | |
1777 | type = WEAK_AN; | |
1778 | else if (bidi_it->prev.type_after_w1 == WEAK_EN | |
1779 | && type_of_next == WEAK_EN | |
1780 | && bidi_it->last_strong.type_after_w1 != STRONG_AL) | |
1781 | type = WEAK_EN; | |
1782 | } | |
1783 | } | |
1784 | else if (type == WEAK_ET /* W5: ET with EN before or after it */ | |
1785 | || type == WEAK_BN) /* W5/Retaining */ | |
1786 | { | |
7b5d6677 | 1787 | if (bidi_it->prev.type_after_w1 == WEAK_EN) /* ET/BN w/EN before it */ |
bc5a45f3 | 1788 | type = WEAK_EN; |
7b5d6677 EZ |
1789 | else if (bidi_it->next_en_pos > bidi_it->charpos |
1790 | && bidi_it->next_en_type != WEAK_BN) | |
1791 | { | |
1792 | if (bidi_it->next_en_type == WEAK_EN) /* ET/BN with EN after it */ | |
1793 | type = WEAK_EN; | |
1794 | } | |
1795 | else if (bidi_it->next_en_pos >=0) | |
bc5a45f3 | 1796 | { |
d311d28c | 1797 | ptrdiff_t en_pos = bidi_it->charpos + bidi_it->nchars; |
512a289d RS |
1798 | const unsigned char *s = (STRINGP (bidi_it->string.lstring) |
1799 | ? SDATA (bidi_it->string.lstring) | |
1800 | : bidi_it->string.s); | |
bc5a45f3 | 1801 | |
102ebb00 | 1802 | if (bidi_it->nchars <= 0) |
1088b922 | 1803 | emacs_abort (); |
512a289d RS |
1804 | next_char |
1805 | = (bidi_it->charpos + bidi_it->nchars >= eob | |
1806 | ? BIDI_EOB | |
1807 | : bidi_char_at_pos (bidi_it->bytepos + bidi_it->ch_len, s, | |
1808 | bidi_it->string.unibyte)); | |
bc5a45f3 EZ |
1809 | type_of_next = bidi_get_type (next_char, override); |
1810 | ||
1811 | if (type_of_next == WEAK_ET | |
1812 | || type_of_next == WEAK_BN | |
1813 | || bidi_explicit_dir_char (next_char)) | |
1814 | { | |
1815 | bidi_copy_it (&saved_it, bidi_it); | |
1816 | while (bidi_resolve_explicit (bidi_it) == new_level | |
1817 | && (bidi_it->type == WEAK_BN | |
1818 | || bidi_it->type == WEAK_ET)) | |
1819 | ; | |
1820 | type_of_next = bidi_it->type; | |
1821 | en_pos = bidi_it->charpos; | |
1822 | bidi_copy_it (bidi_it, &saved_it); | |
1823 | } | |
7b5d6677 EZ |
1824 | /* Remember this position, to speed up processing of the |
1825 | next ETs. */ | |
1826 | bidi_it->next_en_pos = en_pos; | |
bc5a45f3 | 1827 | if (type_of_next == WEAK_EN) |
b7b65b15 | 1828 | { |
bc5a45f3 EZ |
1829 | /* If the last strong character is AL, the EN we've |
1830 | found will become AN when we get to it (W2). */ | |
7b5d6677 EZ |
1831 | if (bidi_it->last_strong.type_after_w1 == STRONG_AL) |
1832 | type_of_next = WEAK_AN; | |
bc5a45f3 EZ |
1833 | else if (type == WEAK_BN) |
1834 | type = NEUTRAL_ON; /* W6/Retaining */ | |
7b5d6677 EZ |
1835 | else |
1836 | type = WEAK_EN; | |
b7b65b15 | 1837 | } |
4787455f EZ |
1838 | else if (type_of_next == NEUTRAL_B) |
1839 | /* Record the fact that there are no more ENs from | |
1840 | here to the end of paragraph, to avoid entering the | |
1841 | loop above ever again in this paragraph. */ | |
1842 | bidi_it->next_en_pos = -1; | |
7b5d6677 EZ |
1843 | /* Record the type of the character where we ended our search. */ |
1844 | bidi_it->next_en_type = type_of_next; | |
b7b65b15 EZ |
1845 | } |
1846 | } | |
1847 | } | |
1848 | ||
1849 | if (type == WEAK_ES || type == WEAK_ET || type == WEAK_CS /* W6 */ | |
89d3374a EZ |
1850 | || (type == WEAK_BN |
1851 | && (bidi_it->prev.type_after_w1 == WEAK_CS /* W6/Retaining */ | |
1852 | || bidi_it->prev.type_after_w1 == WEAK_ES | |
1853 | || bidi_it->prev.type_after_w1 == WEAK_ET))) | |
b7b65b15 EZ |
1854 | type = NEUTRAL_ON; |
1855 | ||
1856 | /* Store the type we've got so far, before we clobber it with strong | |
1857 | types in W7 and while resolving neutral types. But leave alone | |
1858 | the original types that were recorded above, because we will need | |
1859 | them for the L1 clause. */ | |
89d3374a EZ |
1860 | if (bidi_it->type_after_w1 == UNKNOWN_BT) |
1861 | bidi_it->type_after_w1 = type; | |
1862 | bidi_check_type (bidi_it->type_after_w1); | |
b7b65b15 EZ |
1863 | |
1864 | if (type == WEAK_EN) /* W7 */ | |
1865 | { | |
89d3374a | 1866 | if ((bidi_it->last_strong.type_after_w1 == STRONG_L) |
b7b65b15 EZ |
1867 | || (bidi_it->last_strong.type == UNKNOWN_BT && bidi_it->sor == L2R)) |
1868 | type = STRONG_L; | |
1869 | } | |
1870 | ||
1871 | bidi_it->type = type; | |
2d6e4628 | 1872 | bidi_check_type (bidi_it->type); |
b7b65b15 EZ |
1873 | return type; |
1874 | } | |
1875 | ||
cbb09f04 EZ |
1876 | /* Resolve the type of a neutral character according to the type of |
1877 | surrounding strong text and the current embedding level. */ | |
0a99eee1 | 1878 | static bidi_type_t |
cbb09f04 EZ |
1879 | bidi_resolve_neutral_1 (bidi_type_t prev_type, bidi_type_t next_type, int lev) |
1880 | { | |
1881 | /* N1: European and Arabic numbers are treated as though they were R. */ | |
1882 | if (next_type == WEAK_EN || next_type == WEAK_AN) | |
1883 | next_type = STRONG_R; | |
1884 | if (prev_type == WEAK_EN || prev_type == WEAK_AN) | |
1885 | prev_type = STRONG_R; | |
1886 | ||
1887 | if (next_type == prev_type) /* N1 */ | |
1888 | return next_type; | |
1889 | else if ((lev & 1) == 0) /* N2 */ | |
1890 | return STRONG_L; | |
1891 | else | |
1892 | return STRONG_R; | |
1893 | } | |
1894 | ||
fd3998ff | 1895 | static bidi_type_t |
b7b65b15 EZ |
1896 | bidi_resolve_neutral (struct bidi_it *bidi_it) |
1897 | { | |
1898 | int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level; | |
1899 | bidi_type_t type = bidi_resolve_weak (bidi_it); | |
1900 | int current_level = bidi_it->level_stack[bidi_it->stack_idx].level; | |
1901 | ||
1902 | if (!(type == STRONG_R | |
1903 | || type == STRONG_L | |
1904 | || type == WEAK_BN | |
1905 | || type == WEAK_EN | |
1906 | || type == WEAK_AN | |
1907 | || type == NEUTRAL_B | |
1908 | || type == NEUTRAL_S | |
1909 | || type == NEUTRAL_WS | |
1910 | || type == NEUTRAL_ON)) | |
1088b922 | 1911 | emacs_abort (); |
b7b65b15 | 1912 | |
4787455f EZ |
1913 | if ((type != NEUTRAL_B /* Don't risk entering the long loop below if |
1914 | we are already at paragraph end. */ | |
1915 | && bidi_get_category (type) == NEUTRAL) | |
b7b65b15 EZ |
1916 | || (type == WEAK_BN && prev_level == current_level)) |
1917 | { | |
1918 | if (bidi_it->next_for_neutral.type != UNKNOWN_BT) | |
1919 | type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type, | |
1920 | bidi_it->next_for_neutral.type, | |
1921 | current_level); | |
4787455f EZ |
1922 | /* The next two "else if" clauses are shortcuts for the |
1923 | important special case when we have a long sequence of | |
1924 | neutral or WEAK_BN characters, such as whitespace or nulls or | |
1925 | other control characters, on the base embedding level of the | |
1926 | paragraph, and that sequence goes all the way to the end of | |
1927 | the paragraph and follows a character whose resolved | |
1928 | directionality is identical to the base embedding level. | |
1929 | (This is what happens in a buffer with plain L2R text that | |
1930 | happens to include long sequences of control characters.) By | |
1931 | virtue of N1, the result of examining this long sequence will | |
1932 | always be either STRONG_L or STRONG_R, depending on the base | |
1933 | embedding level. So we use this fact directly instead of | |
1934 | entering the expensive loop in the "else" clause. */ | |
1935 | else if (current_level == 0 | |
1936 | && bidi_it->prev_for_neutral.type == STRONG_L | |
1937 | && !bidi_explicit_dir_char (bidi_it->ch)) | |
1938 | type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type, | |
1939 | STRONG_L, current_level); | |
1940 | else if (/* current level is 1 */ | |
1941 | current_level == 1 | |
1942 | /* base embedding level is also 1 */ | |
1943 | && bidi_it->level_stack[0].level == 1 | |
1944 | /* previous character is one of those considered R for | |
1945 | the purposes of W5 */ | |
1946 | && (bidi_it->prev_for_neutral.type == STRONG_R | |
1947 | || bidi_it->prev_for_neutral.type == WEAK_EN | |
1948 | || bidi_it->prev_for_neutral.type == WEAK_AN) | |
1949 | && !bidi_explicit_dir_char (bidi_it->ch)) | |
1950 | type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type, | |
1951 | STRONG_R, current_level); | |
b7b65b15 EZ |
1952 | else |
1953 | { | |
1954 | /* Arrrgh!! The UAX#9 algorithm is too deeply entrenched in | |
1955 | the assumption of batch-style processing; see clauses W4, | |
1956 | W5, and especially N1, which require to look far forward | |
182ce2d2 EZ |
1957 | (as well as back) in the buffer/string. May the fleas of |
1958 | a thousand camels infest the armpits of those who design | |
b7b65b15 EZ |
1959 | supposedly general-purpose algorithms by looking at their |
1960 | own implementations, and fail to consider other possible | |
1961 | implementations! */ | |
1962 | struct bidi_it saved_it; | |
1963 | bidi_type_t next_type; | |
1964 | ||
1965 | if (bidi_it->scan_dir == -1) | |
1088b922 | 1966 | emacs_abort (); |
b7b65b15 EZ |
1967 | |
1968 | bidi_copy_it (&saved_it, bidi_it); | |
1969 | /* Scan the text forward until we find the first non-neutral | |
1970 | character, and then use that to resolve the neutral we | |
1971 | are dealing with now. We also cache the scanned iterator | |
1972 | states, to salvage some of the effort later. */ | |
1973 | bidi_cache_iterator_state (bidi_it, 0); | |
1974 | do { | |
1975 | /* Record the info about the previous character, so that | |
1976 | it will be cached below with this state. */ | |
89d3374a | 1977 | if (bidi_it->type_after_w1 != WEAK_BN /* W1/Retaining */ |
b7b65b15 EZ |
1978 | && bidi_it->type != WEAK_BN) |
1979 | bidi_remember_char (&bidi_it->prev, bidi_it); | |
1980 | type = bidi_resolve_weak (bidi_it); | |
1981 | /* Paragraph separators have their levels fully resolved | |
1982 | at this point, so cache them as resolved. */ | |
1983 | bidi_cache_iterator_state (bidi_it, type == NEUTRAL_B); | |
1984 | /* FIXME: implement L1 here, by testing for a newline and | |
1985 | resetting the level for any sequence of whitespace | |
1986 | characters adjacent to it. */ | |
1987 | } while (!(type == NEUTRAL_B | |
1988 | || (type != WEAK_BN | |
1989 | && bidi_get_category (type) != NEUTRAL) | |
1990 | /* This is all per level run, so stop when we | |
1991 | reach the end of this level run. */ | |
512a289d RS |
1992 | || (bidi_it->level_stack[bidi_it->stack_idx].level |
1993 | != current_level))); | |
b7b65b15 EZ |
1994 | |
1995 | bidi_remember_char (&saved_it.next_for_neutral, bidi_it); | |
1996 | ||
1997 | switch (type) | |
1998 | { | |
1999 | case STRONG_L: | |
2000 | case STRONG_R: | |
2001 | case STRONG_AL: | |
4787455f EZ |
2002 | /* Actually, STRONG_AL cannot happen here, because |
2003 | bidi_resolve_weak converts it to STRONG_R, per W3. */ | |
a54e2c05 | 2004 | eassert (type != STRONG_AL); |
b7b65b15 EZ |
2005 | next_type = type; |
2006 | break; | |
2007 | case WEAK_EN: | |
2008 | case WEAK_AN: | |
2009 | /* N1: ``European and Arabic numbers are treated as | |
2010 | though they were R.'' */ | |
2011 | next_type = STRONG_R; | |
b7b65b15 EZ |
2012 | break; |
2013 | case WEAK_BN: | |
713bfeaa | 2014 | case NEUTRAL_ON: /* W6/Retaining */ |
b7b65b15 | 2015 | if (!bidi_explicit_dir_char (bidi_it->ch)) |
1088b922 | 2016 | emacs_abort (); /* can't happen: BNs are skipped */ |
b7b65b15 EZ |
2017 | /* FALLTHROUGH */ |
2018 | case NEUTRAL_B: | |
2019 | /* Marched all the way to the end of this level run. | |
2020 | We need to use the eor type, whose information is | |
2021 | stored by bidi_set_sor_type in the prev_for_neutral | |
2022 | member. */ | |
2023 | if (saved_it.type != WEAK_BN | |
89d3374a | 2024 | || bidi_get_category (bidi_it->prev.type_after_w1) == NEUTRAL) |
4787455f | 2025 | next_type = bidi_it->prev_for_neutral.type; |
b7b65b15 EZ |
2026 | else |
2027 | { | |
2028 | /* This is a BN which does not adjoin neutrals. | |
2029 | Leave its type alone. */ | |
2030 | bidi_copy_it (bidi_it, &saved_it); | |
2031 | return bidi_it->type; | |
2032 | } | |
2033 | break; | |
2034 | default: | |
1088b922 | 2035 | emacs_abort (); |
b7b65b15 EZ |
2036 | } |
2037 | type = bidi_resolve_neutral_1 (saved_it.prev_for_neutral.type, | |
2038 | next_type, current_level); | |
4787455f | 2039 | saved_it.next_for_neutral.type = next_type; |
b7b65b15 | 2040 | saved_it.type = type; |
4787455f | 2041 | bidi_check_type (next_type); |
2d6e4628 | 2042 | bidi_check_type (type); |
b7b65b15 EZ |
2043 | bidi_copy_it (bidi_it, &saved_it); |
2044 | } | |
2045 | } | |
2046 | return type; | |
2047 | } | |
2048 | ||
2049 | /* Given an iterator state in BIDI_IT, advance one character position | |
182ce2d2 EZ |
2050 | in the buffer/string to the next character (in the logical order), |
2051 | resolve the bidi type of that next character, and return that | |
2052 | type. */ | |
fd3998ff | 2053 | static bidi_type_t |
b7b65b15 EZ |
2054 | bidi_type_of_next_char (struct bidi_it *bidi_it) |
2055 | { | |
2056 | bidi_type_t type; | |
2057 | ||
2058 | /* This should always be called during a forward scan. */ | |
2059 | if (bidi_it->scan_dir != 1) | |
1088b922 | 2060 | emacs_abort (); |
b7b65b15 EZ |
2061 | |
2062 | /* Reset the limit until which to ignore BNs if we step out of the | |
2063 | area where we found only empty levels. */ | |
87e67904 | 2064 | if ((bidi_it->ignore_bn_limit > -1 |
b7b65b15 | 2065 | && bidi_it->ignore_bn_limit <= bidi_it->charpos) |
87e67904 | 2066 | || (bidi_it->ignore_bn_limit == -2 |
b7b65b15 | 2067 | && !bidi_explicit_dir_char (bidi_it->ch))) |
87e67904 | 2068 | bidi_it->ignore_bn_limit = -1; |
b7b65b15 EZ |
2069 | |
2070 | type = bidi_resolve_neutral (bidi_it); | |
2071 | ||
2072 | return type; | |
2073 | } | |
2074 | ||
2075 | /* Given an iterator state BIDI_IT, advance one character position in | |
182ce2d2 EZ |
2076 | the buffer/string to the next character (in the current scan |
2077 | direction), resolve the embedding and implicit levels of that next | |
2078 | character, and return the resulting level. */ | |
fd3998ff | 2079 | static int |
b7b65b15 EZ |
2080 | bidi_level_of_next_char (struct bidi_it *bidi_it) |
2081 | { | |
2082 | bidi_type_t type; | |
2083 | int level, prev_level = -1; | |
2084 | struct bidi_saved_info next_for_neutral; | |
d311d28c | 2085 | ptrdiff_t next_char_pos = -2; |
b7b65b15 EZ |
2086 | |
2087 | if (bidi_it->scan_dir == 1) | |
2088 | { | |
5895d7b9 | 2089 | ptrdiff_t eob |
512a289d RS |
2090 | = ((bidi_it->string.s || STRINGP (bidi_it->string.lstring)) |
2091 | ? bidi_it->string.schars : ZV); | |
9f257352 | 2092 | |
b7b65b15 | 2093 | /* There's no sense in trying to advance if we hit end of text. */ |
9f257352 | 2094 | if (bidi_it->charpos >= eob) |
b7b65b15 EZ |
2095 | return bidi_it->resolved_level; |
2096 | ||
2097 | /* Record the info about the previous character. */ | |
89d3374a | 2098 | if (bidi_it->type_after_w1 != WEAK_BN /* W1/Retaining */ |
b7b65b15 EZ |
2099 | && bidi_it->type != WEAK_BN) |
2100 | bidi_remember_char (&bidi_it->prev, bidi_it); | |
89d3374a EZ |
2101 | if (bidi_it->type_after_w1 == STRONG_R |
2102 | || bidi_it->type_after_w1 == STRONG_L | |
2103 | || bidi_it->type_after_w1 == STRONG_AL) | |
b7b65b15 EZ |
2104 | bidi_remember_char (&bidi_it->last_strong, bidi_it); |
2105 | /* FIXME: it sounds like we don't need both prev and | |
2106 | prev_for_neutral members, but I'm leaving them both for now. */ | |
2107 | if (bidi_it->type == STRONG_R || bidi_it->type == STRONG_L | |
2108 | || bidi_it->type == WEAK_EN || bidi_it->type == WEAK_AN) | |
2109 | bidi_remember_char (&bidi_it->prev_for_neutral, bidi_it); | |
2110 | ||
2111 | /* If we overstepped the characters used for resolving neutrals | |
2112 | and whitespace, invalidate their info in the iterator. */ | |
2113 | if (bidi_it->charpos >= bidi_it->next_for_neutral.charpos) | |
2114 | bidi_it->next_for_neutral.type = UNKNOWN_BT; | |
2115 | if (bidi_it->next_en_pos >= 0 | |
2116 | && bidi_it->charpos >= bidi_it->next_en_pos) | |
7b5d6677 EZ |
2117 | { |
2118 | bidi_it->next_en_pos = 0; | |
2119 | bidi_it->next_en_type = UNKNOWN_BT; | |
2120 | } | |
b7b65b15 EZ |
2121 | if (bidi_it->next_for_ws.type != UNKNOWN_BT |
2122 | && bidi_it->charpos >= bidi_it->next_for_ws.charpos) | |
2123 | bidi_it->next_for_ws.type = UNKNOWN_BT; | |
2124 | ||
2125 | /* This must be taken before we fill the iterator with the info | |
2126 | about the next char. If we scan backwards, the iterator | |
2127 | state must be already cached, so there's no need to know the | |
2128 | embedding level of the previous character, since we will be | |
2129 | returning to our caller shortly. */ | |
2130 | prev_level = bidi_it->level_stack[bidi_it->stack_idx].level; | |
2131 | } | |
2132 | next_for_neutral = bidi_it->next_for_neutral; | |
2133 | ||
182ce2d2 EZ |
2134 | /* Perhaps the character we want is already cached. If it is, the |
2135 | call to bidi_cache_find below will return a type other than | |
2136 | UNKNOWN_BT. */ | |
87e67904 | 2137 | if (bidi_cache_idx > bidi_cache_start && !bidi_it->first_elt) |
102ebb00 | 2138 | { |
512a289d RS |
2139 | int bob = ((bidi_it->string.s || STRINGP (bidi_it->string.lstring)) |
2140 | ? 0 : 1); | |
102ebb00 EZ |
2141 | if (bidi_it->scan_dir > 0) |
2142 | { | |
2143 | if (bidi_it->nchars <= 0) | |
1088b922 | 2144 | emacs_abort (); |
102ebb00 EZ |
2145 | next_char_pos = bidi_it->charpos + bidi_it->nchars; |
2146 | } | |
9f257352 | 2147 | else if (bidi_it->charpos >= bob) |
bb269206 EZ |
2148 | /* Implementation note: we allow next_char_pos to be as low as |
2149 | 0 for buffers or -1 for strings, and that is okay because | |
2150 | that's the "position" of the sentinel iterator state we | |
2151 | cached at the beginning of the iteration. */ | |
102ebb00 | 2152 | next_char_pos = bidi_it->charpos - 1; |
578b494e | 2153 | if (next_char_pos >= bob - 1) |
87e67904 EZ |
2154 | type = bidi_cache_find (next_char_pos, -1, bidi_it); |
2155 | else | |
2156 | type = UNKNOWN_BT; | |
102ebb00 | 2157 | } |
182ce2d2 | 2158 | else |
102ebb00 | 2159 | type = UNKNOWN_BT; |
b7b65b15 EZ |
2160 | if (type != UNKNOWN_BT) |
2161 | { | |
2162 | /* Don't lose the information for resolving neutrals! The | |
2163 | cached states could have been cached before their | |
2164 | next_for_neutral member was computed. If we are on our way | |
2165 | forward, we can simply take the info from the previous | |
2166 | state. */ | |
2167 | if (bidi_it->scan_dir == 1 | |
2168 | && bidi_it->next_for_neutral.type == UNKNOWN_BT) | |
2169 | bidi_it->next_for_neutral = next_for_neutral; | |
2170 | ||
2171 | /* If resolved_level is -1, it means this state was cached | |
2172 | before it was completely resolved, so we cannot return | |
2173 | it. */ | |
2174 | if (bidi_it->resolved_level != -1) | |
2175 | return bidi_it->resolved_level; | |
2176 | } | |
2177 | if (bidi_it->scan_dir == -1) | |
2178 | /* If we are going backwards, the iterator state is already cached | |
2179 | from previous scans, and should be fully resolved. */ | |
1088b922 | 2180 | emacs_abort (); |
b7b65b15 EZ |
2181 | |
2182 | if (type == UNKNOWN_BT) | |
2183 | type = bidi_type_of_next_char (bidi_it); | |
2184 | ||
2185 | if (type == NEUTRAL_B) | |
2186 | return bidi_it->resolved_level; | |
2187 | ||
2188 | level = bidi_it->level_stack[bidi_it->stack_idx].level; | |
2189 | if ((bidi_get_category (type) == NEUTRAL /* && type != NEUTRAL_B */) | |
2190 | || (type == WEAK_BN && prev_level == level)) | |
2191 | { | |
2192 | if (bidi_it->next_for_neutral.type == UNKNOWN_BT) | |
1088b922 | 2193 | emacs_abort (); |
b7b65b15 EZ |
2194 | |
2195 | /* If the cached state shows a neutral character, it was not | |
2196 | resolved by bidi_resolve_neutral, so do it now. */ | |
2197 | type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type, | |
2198 | bidi_it->next_for_neutral.type, | |
2199 | level); | |
2200 | } | |
2201 | ||
2202 | if (!(type == STRONG_R | |
2203 | || type == STRONG_L | |
2204 | || type == WEAK_BN | |
2205 | || type == WEAK_EN | |
2206 | || type == WEAK_AN)) | |
1088b922 | 2207 | emacs_abort (); |
b7b65b15 | 2208 | bidi_it->type = type; |
2d6e4628 | 2209 | bidi_check_type (bidi_it->type); |
b7b65b15 EZ |
2210 | |
2211 | /* For L1 below, we need to know, for each WS character, whether | |
0d327994 | 2212 | it belongs to a sequence of WS characters preceding a newline |
b7b65b15 | 2213 | or a TAB or a paragraph separator. */ |
89d3374a | 2214 | if (bidi_it->orig_type == NEUTRAL_WS |
b7b65b15 EZ |
2215 | && bidi_it->next_for_ws.type == UNKNOWN_BT) |
2216 | { | |
2217 | int ch; | |
d311d28c PE |
2218 | ptrdiff_t clen = bidi_it->ch_len; |
2219 | ptrdiff_t bpos = bidi_it->bytepos; | |
2220 | ptrdiff_t cpos = bidi_it->charpos; | |
2221 | ptrdiff_t disp_pos = bidi_it->disp_pos; | |
2222 | ptrdiff_t nc = bidi_it->nchars; | |
87e67904 | 2223 | struct bidi_string_data bs = bidi_it->string; |
b7b65b15 | 2224 | bidi_type_t chtype; |
2cc21167 | 2225 | bool fwp = bidi_it->frame_window_p; |
0c95fcf7 | 2226 | int dpp = bidi_it->disp_prop; |
b7b65b15 | 2227 | |
102ebb00 | 2228 | if (bidi_it->nchars <= 0) |
1088b922 | 2229 | emacs_abort (); |
b7b65b15 | 2230 | do { |
36075a19 | 2231 | ch = bidi_fetch_char (cpos += nc, bpos += clen, &disp_pos, &dpp, &bs, |
5bf97bfc | 2232 | bidi_it->w, fwp, &clen, &nc); |
79beb178 | 2233 | if (ch == '\n' || ch == BIDI_EOB) |
b7b65b15 EZ |
2234 | chtype = NEUTRAL_B; |
2235 | else | |
6bff6497 | 2236 | chtype = bidi_get_type (ch, NEUTRAL_DIR); |
b7b65b15 EZ |
2237 | } while (chtype == NEUTRAL_WS || chtype == WEAK_BN |
2238 | || bidi_explicit_dir_char (ch)); /* L1/Retaining */ | |
2239 | bidi_it->next_for_ws.type = chtype; | |
2d6e4628 | 2240 | bidi_check_type (bidi_it->next_for_ws.type); |
b7b65b15 EZ |
2241 | bidi_it->next_for_ws.charpos = cpos; |
2242 | bidi_it->next_for_ws.bytepos = bpos; | |
2243 | } | |
2244 | ||
2245 | /* Resolve implicit levels, with a twist: PDFs get the embedding | |
55622b93 | 2246 | level of the embedding they terminate. See below for the |
b7b65b15 | 2247 | reason. */ |
89d3374a | 2248 | if (bidi_it->orig_type == PDF |
b7b65b15 EZ |
2249 | /* Don't do this if this formatting code didn't change the |
2250 | embedding level due to invalid or empty embeddings. */ | |
2251 | && prev_level != level) | |
2252 | { | |
2253 | /* Don't look in UAX#9 for the reason for this: it's our own | |
2254 | private quirk. The reason is that we want the formatting | |
2255 | codes to be delivered so that they bracket the text of their | |
2256 | embedding. For example, given the text | |
2257 | ||
2258 | {RLO}teST{PDF} | |
2259 | ||
2260 | we want it to be displayed as | |
2261 | ||
0d68907d | 2262 | {PDF}STet{RLO} |
b7b65b15 EZ |
2263 | |
2264 | not as | |
2265 | ||
2266 | STet{RLO}{PDF} | |
2267 | ||
2268 | which will result because we bump up the embedding level as | |
2269 | soon as we see the RLO and pop it as soon as we see the PDF, | |
2270 | so RLO itself has the same embedding level as "teST", and | |
2271 | thus would be normally delivered last, just before the PDF. | |
2272 | The switch below fiddles with the level of PDF so that this | |
2273 | ugly side effect does not happen. | |
2274 | ||
2275 | (This is, of course, only important if the formatting codes | |
e7402cb2 EZ |
2276 | are actually displayed, but Emacs does need to display them |
2277 | if the user wants to.) */ | |
b7b65b15 EZ |
2278 | level = prev_level; |
2279 | } | |
89d3374a EZ |
2280 | else if (bidi_it->orig_type == NEUTRAL_B /* L1 */ |
2281 | || bidi_it->orig_type == NEUTRAL_S | |
e7402cb2 | 2282 | || bidi_it->ch == '\n' || bidi_it->ch == BIDI_EOB |
89d3374a | 2283 | || (bidi_it->orig_type == NEUTRAL_WS |
b7b65b15 EZ |
2284 | && (bidi_it->next_for_ws.type == NEUTRAL_B |
2285 | || bidi_it->next_for_ws.type == NEUTRAL_S))) | |
2286 | level = bidi_it->level_stack[0].level; | |
2287 | else if ((level & 1) == 0) /* I1 */ | |
2288 | { | |
2289 | if (type == STRONG_R) | |
2290 | level++; | |
2291 | else if (type == WEAK_EN || type == WEAK_AN) | |
2292 | level += 2; | |
2293 | } | |
2294 | else /* I2 */ | |
2295 | { | |
2296 | if (type == STRONG_L || type == WEAK_EN || type == WEAK_AN) | |
2297 | level++; | |
2298 | } | |
2299 | ||
2300 | bidi_it->resolved_level = level; | |
2301 | return level; | |
2302 | } | |
2303 | ||
2cc21167 PE |
2304 | /* Move to the other edge of a level given by LEVEL. If END_FLAG, |
2305 | we are at the end of a level, and we need to prepare to | |
b7b65b15 EZ |
2306 | resume the scan of the lower level. |
2307 | ||
2308 | If this level's other edge is cached, we simply jump to it, filling | |
2309 | the iterator structure with the iterator state on the other edge. | |
182ce2d2 EZ |
2310 | Otherwise, we walk the buffer or string until we come back to the |
2311 | same level as LEVEL. | |
b7b65b15 EZ |
2312 | |
2313 | Note: we are not talking here about a ``level run'' in the UAX#9 | |
2314 | sense of the term, but rather about a ``level'' which includes | |
2315 | all the levels higher than it. In other words, given the levels | |
2316 | like this: | |
2317 | ||
2318 | 11111112222222333333334443343222222111111112223322111 | |
2319 | A B C | |
2320 | ||
2321 | and assuming we are at point A scanning left to right, this | |
2322 | function moves to point C, whereas the UAX#9 ``level 2 run'' ends | |
2323 | at point B. */ | |
2324 | static void | |
2cc21167 | 2325 | bidi_find_other_level_edge (struct bidi_it *bidi_it, int level, bool end_flag) |
b7b65b15 EZ |
2326 | { |
2327 | int dir = end_flag ? -bidi_it->scan_dir : bidi_it->scan_dir; | |
39e378da | 2328 | ptrdiff_t idx; |
b7b65b15 EZ |
2329 | |
2330 | /* Try the cache first. */ | |
87e67904 EZ |
2331 | if ((idx = bidi_cache_find_level_change (level, dir, end_flag)) |
2332 | >= bidi_cache_start) | |
b7b65b15 EZ |
2333 | bidi_cache_fetch_state (idx, bidi_it); |
2334 | else | |
2335 | { | |
2336 | int new_level; | |
2337 | ||
1088b922 | 2338 | /* If we are at end of level, its edges must be cached. */ |
b7b65b15 | 2339 | if (end_flag) |
1088b922 | 2340 | emacs_abort (); |
b7b65b15 EZ |
2341 | |
2342 | bidi_cache_iterator_state (bidi_it, 1); | |
2343 | do { | |
2344 | new_level = bidi_level_of_next_char (bidi_it); | |
2345 | bidi_cache_iterator_state (bidi_it, 1); | |
2346 | } while (new_level >= level); | |
2347 | } | |
2348 | } | |
2349 | ||
2350 | void | |
4b292a22 | 2351 | bidi_move_to_visually_next (struct bidi_it *bidi_it) |
b7b65b15 EZ |
2352 | { |
2353 | int old_level, new_level, next_level; | |
9c82e145 | 2354 | struct bidi_it sentinel; |
acb28818 | 2355 | struct gcpro gcpro1; |
b7b65b15 | 2356 | |
87e67904 | 2357 | if (bidi_it->charpos < 0 || bidi_it->bytepos < 0) |
1088b922 | 2358 | emacs_abort (); |
b7b65b15 EZ |
2359 | |
2360 | if (bidi_it->scan_dir == 0) | |
2361 | { | |
2362 | bidi_it->scan_dir = 1; /* default to logical order */ | |
2363 | } | |
2364 | ||
acb28818 | 2365 | /* The code below can call eval, and thus cause GC. If we are |
7e2ad32c | 2366 | iterating a Lisp string, make sure it won't be GCed. */ |
acb28818 EZ |
2367 | if (STRINGP (bidi_it->string.lstring)) |
2368 | GCPRO1 (bidi_it->string.lstring); | |
2369 | ||
be39f003 | 2370 | /* If we just passed a newline, initialize for the next line. */ |
1137e8b8 EZ |
2371 | if (!bidi_it->first_elt |
2372 | && (bidi_it->ch == '\n' || bidi_it->ch == BIDI_EOB)) | |
be39f003 EZ |
2373 | bidi_line_init (bidi_it); |
2374 | ||
6dcfd253 EZ |
2375 | /* Prepare the sentinel iterator state, and cache it. When we bump |
2376 | into it, scanning backwards, we'll know that the last non-base | |
2377 | level is exhausted. */ | |
87e67904 | 2378 | if (bidi_cache_idx == bidi_cache_start) |
9c82e145 EZ |
2379 | { |
2380 | bidi_copy_it (&sentinel, bidi_it); | |
2381 | if (bidi_it->first_elt) | |
2382 | { | |
2383 | sentinel.charpos--; /* cached charpos needs to be monotonic */ | |
2384 | sentinel.bytepos--; | |
2385 | sentinel.ch = '\n'; /* doesn't matter, but why not? */ | |
2386 | sentinel.ch_len = 1; | |
182ce2d2 | 2387 | sentinel.nchars = 1; |
9c82e145 | 2388 | } |
6dcfd253 | 2389 | bidi_cache_iterator_state (&sentinel, 1); |
9c82e145 | 2390 | } |
b7b65b15 EZ |
2391 | |
2392 | old_level = bidi_it->resolved_level; | |
2393 | new_level = bidi_level_of_next_char (bidi_it); | |
b7b65b15 EZ |
2394 | |
2395 | /* Reordering of resolved levels (clause L2) is implemented by | |
2396 | jumping to the other edge of the level and flipping direction of | |
c0546589 | 2397 | scanning the text whenever we find a level change. */ |
b7b65b15 EZ |
2398 | if (new_level != old_level) |
2399 | { | |
2cc21167 | 2400 | bool ascending = new_level > old_level; |
b7b65b15 EZ |
2401 | int level_to_search = ascending ? old_level + 1 : old_level; |
2402 | int incr = ascending ? 1 : -1; | |
2403 | int expected_next_level = old_level + incr; | |
2404 | ||
b7b65b15 EZ |
2405 | /* Jump (or walk) to the other edge of this level. */ |
2406 | bidi_find_other_level_edge (bidi_it, level_to_search, !ascending); | |
2407 | /* Switch scan direction and peek at the next character in the | |
2408 | new direction. */ | |
2409 | bidi_it->scan_dir = -bidi_it->scan_dir; | |
2410 | ||
2411 | /* The following loop handles the case where the resolved level | |
2412 | jumps by more than one. This is typical for numbers inside a | |
2413 | run of text with left-to-right embedding direction, but can | |
2414 | also happen in other situations. In those cases the decision | |
2415 | where to continue after a level change, and in what direction, | |
2416 | is tricky. For example, given a text like below: | |
2417 | ||
2418 | abcdefgh | |
2419 | 11336622 | |
2420 | ||
2421 | (where the numbers below the text show the resolved levels), | |
2422 | the result of reordering according to UAX#9 should be this: | |
2423 | ||
2424 | efdcghba | |
2425 | ||
2426 | This is implemented by the loop below which flips direction | |
2427 | and jumps to the other edge of the level each time it finds | |
2428 | the new level not to be the expected one. The expected level | |
2429 | is always one more or one less than the previous one. */ | |
2430 | next_level = bidi_peek_at_next_level (bidi_it); | |
2431 | while (next_level != expected_next_level) | |
2432 | { | |
713bfeaa EZ |
2433 | /* If next_level is -1, it means we have an unresolved level |
2434 | in the cache, which at this point should not happen. If | |
2435 | it does, we will infloop. */ | |
2436 | eassert (next_level >= 0); | |
b7b65b15 EZ |
2437 | expected_next_level += incr; |
2438 | level_to_search += incr; | |
2439 | bidi_find_other_level_edge (bidi_it, level_to_search, !ascending); | |
2440 | bidi_it->scan_dir = -bidi_it->scan_dir; | |
2441 | next_level = bidi_peek_at_next_level (bidi_it); | |
2442 | } | |
2443 | ||
2444 | /* Finally, deliver the next character in the new direction. */ | |
2445 | next_level = bidi_level_of_next_char (bidi_it); | |
2446 | } | |
2447 | ||
b44d9321 EZ |
2448 | /* Take note when we have just processed the newline that precedes |
2449 | the end of the paragraph. The next time we are about to be | |
2450 | called, set_iterator_to_next will automatically reinit the | |
2451 | paragraph direction, if needed. We do this at the newline before | |
2452 | the paragraph separator, because the next character might not be | |
2453 | the first character of the next paragraph, due to the bidi | |
c0546589 EZ |
2454 | reordering, whereas we _must_ know the paragraph base direction |
2455 | _before_ we process the paragraph's text, since the base | |
2456 | direction affects the reordering. */ | |
1137e8b8 EZ |
2457 | if (bidi_it->scan_dir == 1 |
2458 | && (bidi_it->ch == '\n' || bidi_it->ch == BIDI_EOB)) | |
be39f003 | 2459 | { |
87e67904 EZ |
2460 | /* The paragraph direction of the entire string, once |
2461 | determined, is in effect for the entire string. Setting the | |
2462 | separator limit to the end of the string prevents | |
2463 | bidi_paragraph_init from being called automatically on this | |
2464 | string. */ | |
9f257352 | 2465 | if (bidi_it->string.s || STRINGP (bidi_it->string.lstring)) |
87e67904 EZ |
2466 | bidi_it->separator_limit = bidi_it->string.schars; |
2467 | else if (bidi_it->bytepos < ZV_BYTE) | |
be39f003 | 2468 | { |
5895d7b9 | 2469 | ptrdiff_t sep_len |
512a289d RS |
2470 | = bidi_at_paragraph_end (bidi_it->charpos + bidi_it->nchars, |
2471 | bidi_it->bytepos + bidi_it->ch_len); | |
87e67904 | 2472 | if (bidi_it->nchars <= 0) |
1088b922 | 2473 | emacs_abort (); |
87e67904 EZ |
2474 | if (sep_len >= 0) |
2475 | { | |
2476 | bidi_it->new_paragraph = 1; | |
2477 | /* Record the buffer position of the last character of the | |
2478 | paragraph separator. */ | |
512a289d RS |
2479 | bidi_it->separator_limit |
2480 | = bidi_it->charpos + bidi_it->nchars + sep_len; | |
87e67904 | 2481 | } |
be39f003 EZ |
2482 | } |
2483 | } | |
6bff6497 | 2484 | |
87e67904 | 2485 | if (bidi_it->scan_dir == 1 && bidi_cache_idx > bidi_cache_start) |
b7b65b15 EZ |
2486 | { |
2487 | /* If we are at paragraph's base embedding level and beyond the | |
2488 | last cached position, the cache's job is done and we can | |
2489 | discard it. */ | |
2490 | if (bidi_it->resolved_level == bidi_it->level_stack[0].level | |
182ce2d2 EZ |
2491 | && bidi_it->charpos > (bidi_cache[bidi_cache_idx - 1].charpos |
2492 | + bidi_cache[bidi_cache_idx - 1].nchars - 1)) | |
b7b65b15 EZ |
2493 | bidi_cache_reset (); |
2494 | /* But as long as we are caching during forward scan, we must | |
2495 | cache each state, or else the cache integrity will be | |
2496 | compromised: it assumes cached states correspond to buffer | |
2497 | positions 1:1. */ | |
2498 | else | |
2499 | bidi_cache_iterator_state (bidi_it, 1); | |
2500 | } | |
acb28818 EZ |
2501 | |
2502 | if (STRINGP (bidi_it->string.lstring)) | |
2503 | UNGCPRO; | |
b7b65b15 EZ |
2504 | } |
2505 | ||
2506 | /* This is meant to be called from within the debugger, whenever you | |
2507 | wish to examine the cache contents. */ | |
e78aecca | 2508 | void bidi_dump_cached_states (void) EXTERNALLY_VISIBLE; |
b7b65b15 EZ |
2509 | void |
2510 | bidi_dump_cached_states (void) | |
2511 | { | |
39e378da | 2512 | ptrdiff_t i; |
b7b65b15 EZ |
2513 | int ndigits = 1; |
2514 | ||
2515 | if (bidi_cache_idx == 0) | |
2516 | { | |
2517 | fprintf (stderr, "The cache is empty.\n"); | |
2518 | return; | |
2519 | } | |
df9733bf | 2520 | fprintf (stderr, "Total of %"pD"d state%s in cache:\n", |
b7b65b15 EZ |
2521 | bidi_cache_idx, bidi_cache_idx == 1 ? "" : "s"); |
2522 | ||
2523 | for (i = bidi_cache[bidi_cache_idx - 1].charpos; i > 0; i /= 10) | |
2524 | ndigits++; | |
2525 | fputs ("ch ", stderr); | |
2526 | for (i = 0; i < bidi_cache_idx; i++) | |
2527 | fprintf (stderr, "%*c", ndigits, bidi_cache[i].ch); | |
2528 | fputs ("\n", stderr); | |
2529 | fputs ("lvl ", stderr); | |
2530 | for (i = 0; i < bidi_cache_idx; i++) | |
2531 | fprintf (stderr, "%*d", ndigits, bidi_cache[i].resolved_level); | |
2532 | fputs ("\n", stderr); | |
2533 | fputs ("pos ", stderr); | |
2534 | for (i = 0; i < bidi_cache_idx; i++) | |
7c85f529 | 2535 | fprintf (stderr, "%*"pD"d", ndigits, bidi_cache[i].charpos); |
b7b65b15 EZ |
2536 | fputs ("\n", stderr); |
2537 | } |