aboutsummaryrefslogtreecommitdiffstats
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/ChangeLog.bidi64
-rw-r--r--src/Makefile.in2
-rw-r--r--src/bidi.c2134
-rw-r--r--src/buffer.c33
-rw-r--r--src/buffer.h6
-rw-r--r--src/dispextern.h85
-rw-r--r--src/dispnew.c8
-rw-r--r--src/xdisp.c27
8 files changed, 2343 insertions, 16 deletions
diff --git a/src/ChangeLog.bidi b/src/ChangeLog.bidi
new file mode 100644
index 00000000000..415e6a5c468
--- /dev/null
+++ b/src/ChangeLog.bidi
@@ -0,0 +1,64 @@
12005-12-03 Eli Zaretskii <eliz@gnu.org>
2
3 * bidi.c: Include stdio.h unconditionally. Fix and elaborate
4 commentary. Add Copyright blurb.
5
62004-03-08 Kenichi Handa <handa@m17n.org>
7
8 * xdisp.c (reseat_1): Call bidi_init_it with a previous position.
9
10 * bidi.c (bidi_init_it): Set bidi_it->ch_len even if POS > 0.
11
122004-03-04 Kenichi Handa <handa@m17n.org>
13
14 The following changes are to support bidirectional text display.
15
16 * Makefile.in (obj): Include bidi.o.
17 (bidi.o): New target.
18
19 * bidi.c: New file.
20
21 * buffer.h (struct buffer): New member bidi_display_reordering.
22
23 * buffer.c (init_buffer_once): Initialize bidi_display_reordering.
24 (syms_of_buffer): Declarations of Lisp variables
25 default-bidi-display-reordering and bidi-display-reordering.
26
27 * dispextern.h (BIDI_MAXLEVEL): New macro.
28 (bidi_type_t, bidi_dir_t): New types.
29 (bidi_saved_info, bidi_stack, bidi_it): New structs.
30 (struct it): New members bidi_p and bidi_it.
31 (bidi_init_it): Extern it.
32 (bidi_get_next_char_visually): Extern it.
33
34 * dispnew.c (direct_output_forward_char): Give up if we need bidi
35 processing or buffer's direction is right-to-left.
36
37 * xdisp.c (init_iterator): Initialize it->bidi_p.
38 (reseat_1): Cal bidi_init_it and bidi_get_next_char_visually if
39 necessary.
40 (set_iterator_to_next): Cal bidi_get_next_char_visually if
41 necessary.
42
43
44;; Local Variables:
45;; coding: utf-8
46;; add-log-time-zone-rule: t
47;; End:
48
49 Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc.
50
51 This file is part of GNU Emacs.
52
53 GNU Emacs is free software: you can redistribute it and/or modify
54 it under the terms of the GNU General Public License as published by
55 the Free Software Foundation, either version 3 of the License, or
56 (at your option) any later version.
57
58 GNU Emacs is distributed in the hope that it will be useful,
59 but WITHOUT ANY WARRANTY; without even the implied warranty of
60 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
61 GNU General Public License for more details.
62
63 You should have received a copy of the GNU General Public License
64 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
diff --git a/src/Makefile.in b/src/Makefile.in
index 1e956ae826b..f5b7133a7ae 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -560,6 +560,7 @@ FONT_DRIVERS = xfont.o
560/* lastfile must follow all files 560/* lastfile must follow all files
561 whose initialized data areas should be dumped as pure by dump-emacs. */ 561 whose initialized data areas should be dumped as pure by dump-emacs. */
562obj= dispnew.o frame.o scroll.o xdisp.o menu.o $(XMENU_OBJ) window.o \ 562obj= dispnew.o frame.o scroll.o xdisp.o menu.o $(XMENU_OBJ) window.o \
563 bidi.o \
563 charset.o coding.o category.o ccl.o character.o chartab.o \ 564 charset.o coding.o category.o ccl.o character.o chartab.o \
564 cm.o term.o terminal.o xfaces.o $(XOBJ) $(GTK_OBJ) $(DBUS_OBJ) \ 565 cm.o term.o terminal.o xfaces.o $(XOBJ) $(GTK_OBJ) $(DBUS_OBJ) \
565 emacs.o keyboard.o macros.o keymap.o sysdep.o \ 566 emacs.o keyboard.o macros.o keymap.o sysdep.o \
@@ -1052,6 +1053,7 @@ doc.o: buildobj.h
1052 1053
1053atimer.o: atimer.c atimer.h syssignal.h systime.h lisp.h blockinput.h \ 1054atimer.o: atimer.c atimer.h syssignal.h systime.h lisp.h blockinput.h \
1054 $(config_h) 1055 $(config_h)
1056bidi.o: bidi.c buffer.h character.h
1055buffer.o: buffer.c buffer.h region-cache.h commands.h window.h \ 1057buffer.o: buffer.c buffer.h region-cache.h commands.h window.h \
1056 $(INTERVALS_H) blockinput.h atimer.h systime.h character.h \ 1058 $(INTERVALS_H) blockinput.h atimer.h systime.h character.h \
1057 indent.h keyboard.h coding.h keymap.h frame.h lisp.h $(config_h) 1059 indent.h keyboard.h coding.h keymap.h frame.h lisp.h $(config_h)
diff --git a/src/bidi.c b/src/bidi.c
new file mode 100644
index 00000000000..2a3a9706767
--- /dev/null
+++ b/src/bidi.c
@@ -0,0 +1,2134 @@
1/* Low-level bidirectional buffer-scanning functions for GNU Emacs.
2 Copyright (C) 2000, 2001, 2004, 2005 Free Software Foundation, Inc.
3
4This file is part of GNU Emacs.
5
6GNU Emacs is free software; you can redistribute it and/or modify
7it under the terms of the GNU General Public License as published by
8the Free Software Foundation; either version 2, or (at your option)
9any later version.
10
11GNU Emacs is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14GNU General Public License for more details.
15
16
17You should have received a copy of the GNU General Public License
18along with GNU Emacs; see the file COPYING. If not, write to
19the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20Boston, MA 02110-1301, USA. */
21
22/* A sequential implementation of the Unicode Bidirectional algorithm,
23 as per UAX#9, a part of the Unicode Standard.
24
25 Unlike the reference and most other implementations, this one is
26 designed to be called once for every character in the buffer.
27
28 The main entry point is bidi_get_next_char_visually. Each time it
29 is called, it finds the next character in the visual order, and
30 returns its information in a special structure. The caller is then
31 expected to process this character for display or any other
32 purposes, and call bidi_get_next_char_visually for the next
33 character. See the comments in bidi_get_next_char_visually for
34 more details about its algorithm that finds the next visual-order
35 character by resolving their levels on the fly.
36
37 A note about references to UAX#9 rules: if the reference says
38 something like "X9/Retaining", it means that you need to refer to
39 rule X9 and to its modifications decribed in the "Implementation
40 Notes" section of UAX#9, under "Retaining Format Codes". */
41
42#ifdef HAVE_CONFIG_H
43#include <config.h>
44#endif
45
46#include <stdio.h>
47
48#ifdef HAVE_STRING_H
49#include <string.h>
50#endif
51
52#include "lisp.h"
53#include "buffer.h"
54#include "character.h"
55#include "dispextern.h"
56
57static int bidi_initialized = 0;
58
59static Lisp_Object bidi_type_table;
60
61#define LRM_CHAR 0x200E
62#define RLM_CHAR 0x200F
63#define LRE_CHAR 0x202A
64#define RLE_CHAR 0x202B
65#define PDF_CHAR 0x202C
66#define LRO_CHAR 0x202D
67#define RLO_CHAR 0x202E
68
69#define CHARSET_HEBREW 0x88
70#define CHARSET_ARABIC 0x87
71#define CHARSET_SYRIAC -1 /* these are undefined yet, -1 is invalid */
72#define CHARSET_THAANA -1
73
74/* FIXME: need to define wrappers for FETCH_CHAR etc. that return
75 BIDI_EOB when they hit ZV. */
76#define BIDI_EOB -1
77#define BIDI_BOB -2
78
79#ifdef TEST_STANDALONE
80/* Testing. */
81
82static unsigned char *input_buf;
83static size_t input_buf_size;
84
85int _fetch_multibyte_char_len, _c_c_;
86
87#undef FETCH_CHAR_ADVANCE
88#define FETCH_CHAR_ADVANCE(ch, cp, bp) \
89 do { \
90 ch = input_buf[cp]; \
91 (cp)++; \
92 (bp)++; \
93 if (ch == '\0') \
94 ch = BIDI_EOB; \
95 } while (0)
96
97#undef FETCH_CHAR
98#define FETCH_CHAR(n) ((_c_c_ = input_buf[n]) ? _c_c_ : BIDI_EOB)
99
100#undef CHAR_CHARSET
101#define CHAR_CHARSET(c) \
102 (((c) >= 128 || ((c) < 8 && (c)) || ((c) >= 'A' && (c) < 'X')) \
103 ? CHARSET_HEBREW \
104 : ((((c) >= 'X' && (c) <= 'Z') || ((c) >= '6' && (c) <= '9')) \
105 ? CHARSET_ARABIC \
106 : CHARSET_ASCII))
107
108#undef CHAR_TO_BYTE
109#define CHAR_TO_BYTE(pos) (pos)
110
111#define char_bytes(ch) 1
112
113#undef LRE_CHAR
114#undef LRO_CHAR
115#undef RLE_CHAR
116#undef RLO_CHAR
117#undef PDF_CHAR
118#undef RLM_CHAR
119#undef LRM_CHAR
120
121#define LRE_CHAR 1
122#define LRO_CHAR 2
123#define RLE_CHAR 3
124#define RLO_CHAR 4
125#define PDF_CHAR 5
126#define RLM_CHAR 6
127#define LRM_CHAR 7
128
129static const char *bidi_name[] =
130 {
131 "[???]", "[LRE]", "[LRO]", "[RLE]", "[RLO]", "[PDF]", "[RLM]", "[LRM]"
132 };
133
134#endif /* TEST_STANDALONE */
135
136/* Local data structures. (Look in dispextern.h for the rest.) */
137
138/* What we need to know about the current paragraph. */
139struct bidi_paragraph_info {
140 int start_bytepos; /* byte position where it begins */
141 int end_bytepos; /* byte position where it ends */
142 int embedding_level; /* its basic embedding level */
143 bidi_dir_t base_dir; /* its base direction */
144};
145
146/* Data type for describing the bidirectional character categories. */
147typedef enum {
148 UNKNOWN_BC,
149 NEUTRAL,
150 WEAK,
151 STRONG
152} bidi_category_t;
153
154int bidi_ignore_explicit_marks_for_paragraph_level = 1;
155
156bidi_dir_t bidi_overriding_paragraph_direction = NEUTRAL_DIR;
157
158#define ASCII_BIDI_TYPE_SET(STR, TYPE) \
159 do { \
160 unsigned char *p; \
161 for (p = (STR); *p; p++) \
162 CHAR_TABLE_SET (bidi_type_table, *p, (TYPE)); \
163 } while (0)
164
165static void
166bidi_initialize ()
167{
168 /* FIXME: This should come from the Unicode Database. */
169 struct {
170 int from, to;
171 bidi_type_t type;
172 } bidi_type[] =
173 { { 0x0000, 0x0008, WEAK_BN },
174 { 0x0009, 0x0000, NEUTRAL_S },
175 { 0x000A, 0x0000, NEUTRAL_B },
176 { 0x000B, 0x0000, NEUTRAL_S },
177 { 0x000C, 0x0000, NEUTRAL_WS },
178 { 0x000D, 0x0000, NEUTRAL_B },
179 { 0x000E, 0x001B, WEAK_BN },
180 { 0x001C, 0x001E, NEUTRAL_B },
181 { 0x001F, 0x0000, NEUTRAL_S },
182 { 0x0020, 0x0000, NEUTRAL_WS },
183 { 0x0021, 0x0022, NEUTRAL_ON },
184 { 0x0023, 0x0025, WEAK_ET },
185 { 0x0026, 0x002A, NEUTRAL_ON },
186 { 0x002B, 0x0000, WEAK_ET },
187 { 0x002C, 0x0000, WEAK_CS },
188 { 0x002D, 0x0000, WEAK_ET },
189 { 0x002E, 0x0000, WEAK_CS },
190 { 0x002F, 0x0000, WEAK_ES },
191 { 0x0030, 0x0039, WEAK_EN },
192 { 0x003A, 0x0000, WEAK_CS },
193 { 0x003B, 0x0040, NEUTRAL_ON },
194 { 0x005B, 0x0060, NEUTRAL_ON },
195 { 0x007B, 0x007E, NEUTRAL_ON },
196 { 0x007F, 0x0084, WEAK_BN },
197 { 0x0085, 0x0000, NEUTRAL_B },
198 { 0x0086, 0x009F, WEAK_BN },
199 { 0x00A0, 0x0000, WEAK_CS },
200 { 0x00A1, 0x0000, NEUTRAL_ON },
201 { 0x00A2, 0x00A5, WEAK_ET },
202 { 0x00A6, 0x00A9, NEUTRAL_ON },
203 { 0x00AB, 0x00AF, NEUTRAL_ON },
204 { 0x00B0, 0x00B1, WEAK_ET },
205 { 0x00B2, 0x00B3, WEAK_EN },
206 { 0x00B4, 0x0000, NEUTRAL_ON },
207 { 0x00B6, 0x00B8, NEUTRAL_ON },
208 { 0x00B9, 0x0000, WEAK_EN },
209 { 0x00BB, 0x00BF, NEUTRAL_ON },
210 { 0x00D7, 0x0000, NEUTRAL_ON },
211 { 0x00F7, 0x0000, NEUTRAL_ON },
212 { 0x02B9, 0x02BA, NEUTRAL_ON },
213 { 0x02C2, 0x02CF, NEUTRAL_ON },
214 { 0x02D2, 0x02DF, NEUTRAL_ON },
215 { 0x02E5, 0x02ED, NEUTRAL_ON },
216 { 0x0300, 0x036F, WEAK_NSM },
217 { 0x0374, 0x0375, NEUTRAL_ON },
218 { 0x037E, 0x0385, NEUTRAL_ON },
219 { 0x0387, 0x0000, NEUTRAL_ON },
220 { 0x03F6, 0x0000, NEUTRAL_ON },
221 { 0x0483, 0x0489, WEAK_NSM },
222 { 0x058A, 0x0000, NEUTRAL_ON },
223 { 0x0591, 0x05BD, WEAK_NSM },
224 { 0x05BE, 0x0000, STRONG_R },
225 { 0x05BF, 0x0000, WEAK_NSM },
226 { 0x05C0, 0x0000, STRONG_R },
227 { 0x05C1, 0x05C2, WEAK_NSM },
228 { 0x05C3, 0x0000, STRONG_R },
229 { 0x05C4, 0x0000, WEAK_NSM },
230 { 0x05D0, 0x05F4, STRONG_R },
231 { 0x060C, 0x0000, WEAK_CS },
232 { 0x061B, 0x064A, STRONG_AL },
233 { 0x064B, 0x0655, WEAK_NSM },
234 { 0x0660, 0x0669, WEAK_AN },
235 { 0x066A, 0x0000, WEAK_ET },
236 { 0x066B, 0x066C, WEAK_AN },
237 { 0x066D, 0x066F, STRONG_AL },
238 { 0x0670, 0x0000, WEAK_NSM },
239 { 0x0671, 0x06D5, STRONG_AL },
240 { 0x06D6, 0x06DC, WEAK_NSM },
241 { 0x06DD, 0x0000, STRONG_AL },
242 { 0x06DE, 0x06E4, WEAK_NSM },
243 { 0x06E5, 0x06E6, STRONG_AL },
244 { 0x06E7, 0x06E8, WEAK_NSM },
245 { 0x06E9, 0x0000, NEUTRAL_ON },
246 { 0x06EA, 0x06ED, WEAK_NSM },
247 { 0x06F0, 0x06F9, WEAK_EN },
248 { 0x06FA, 0x070D, STRONG_AL },
249 { 0x070F, 0x0000, WEAK_BN },
250 { 0x0710, 0x0000, STRONG_AL },
251 { 0x0711, 0x0000, WEAK_NSM },
252 { 0x0712, 0x072C, STRONG_AL },
253 { 0x0730, 0x074A, WEAK_NSM },
254 { 0x0780, 0x07A5, STRONG_AL },
255 { 0x07A6, 0x07B0, WEAK_NSM },
256 { 0x07B1, 0x0000, STRONG_AL },
257 { 0x0901, 0x0902, WEAK_NSM },
258 { 0x093C, 0x0000, WEAK_NSM },
259 { 0x0941, 0x0948, WEAK_NSM },
260 { 0x094D, 0x0000, WEAK_NSM },
261 { 0x0951, 0x0954, WEAK_NSM },
262 { 0x0962, 0x0963, WEAK_NSM },
263 { 0x0981, 0x0000, WEAK_NSM },
264 { 0x09BC, 0x0000, WEAK_NSM },
265 { 0x09C1, 0x09C4, WEAK_NSM },
266 { 0x09CD, 0x0000, WEAK_NSM },
267 { 0x09E2, 0x09E3, WEAK_NSM },
268 { 0x09F2, 0x09F3, WEAK_ET },
269 { 0x0A02, 0x0000, WEAK_NSM },
270 { 0x0A3C, 0x0000, WEAK_NSM },
271 { 0x0A41, 0x0A4D, WEAK_NSM },
272 { 0x0A70, 0x0A71, WEAK_NSM },
273 { 0x0A81, 0x0A82, WEAK_NSM },
274 { 0x0ABC, 0x0000, WEAK_NSM },
275 { 0x0AC1, 0x0AC8, WEAK_NSM },
276 { 0x0ACD, 0x0000, WEAK_NSM },
277 { 0x0B01, 0x0000, WEAK_NSM },
278 { 0x0B3C, 0x0000, WEAK_NSM },
279 { 0x0B3F, 0x0000, WEAK_NSM },
280 { 0x0B41, 0x0B43, WEAK_NSM },
281 { 0x0B4D, 0x0B56, WEAK_NSM },
282 { 0x0B82, 0x0000, WEAK_NSM },
283 { 0x0BC0, 0x0000, WEAK_NSM },
284 { 0x0BCD, 0x0000, WEAK_NSM },
285 { 0x0C3E, 0x0C40, WEAK_NSM },
286 { 0x0C46, 0x0C56, WEAK_NSM },
287 { 0x0CBF, 0x0000, WEAK_NSM },
288 { 0x0CC6, 0x0000, WEAK_NSM },
289 { 0x0CCC, 0x0CCD, WEAK_NSM },
290 { 0x0D41, 0x0D43, WEAK_NSM },
291 { 0x0D4D, 0x0000, WEAK_NSM },
292 { 0x0DCA, 0x0000, WEAK_NSM },
293 { 0x0DD2, 0x0DD6, WEAK_NSM },
294 { 0x0E31, 0x0000, WEAK_NSM },
295 { 0x0E34, 0x0E3A, WEAK_NSM },
296 { 0x0E3F, 0x0000, WEAK_ET },
297 { 0x0E47, 0x0E4E, WEAK_NSM },
298 { 0x0EB1, 0x0000, WEAK_NSM },
299 { 0x0EB4, 0x0EBC, WEAK_NSM },
300 { 0x0EC8, 0x0ECD, WEAK_NSM },
301 { 0x0F18, 0x0F19, WEAK_NSM },
302 { 0x0F35, 0x0000, WEAK_NSM },
303 { 0x0F37, 0x0000, WEAK_NSM },
304 { 0x0F39, 0x0000, WEAK_NSM },
305 { 0x0F3A, 0x0F3D, NEUTRAL_ON },
306 { 0x0F71, 0x0F7E, WEAK_NSM },
307 { 0x0F80, 0x0F84, WEAK_NSM },
308 { 0x0F86, 0x0F87, WEAK_NSM },
309 { 0x0F90, 0x0FBC, WEAK_NSM },
310 { 0x0FC6, 0x0000, WEAK_NSM },
311 { 0x102D, 0x1030, WEAK_NSM },
312 { 0x1032, 0x1037, WEAK_NSM },
313 { 0x1039, 0x0000, WEAK_NSM },
314 { 0x1058, 0x1059, WEAK_NSM },
315 { 0x1680, 0x0000, NEUTRAL_WS },
316 { 0x169B, 0x169C, NEUTRAL_ON },
317 { 0x1712, 0x1714, WEAK_NSM },
318 { 0x1732, 0x1734, WEAK_NSM },
319 { 0x1752, 0x1753, WEAK_NSM },
320 { 0x1772, 0x1773, WEAK_NSM },
321 { 0x17B7, 0x17BD, WEAK_NSM },
322 { 0x17C6, 0x0000, WEAK_NSM },
323 { 0x17C9, 0x17D3, WEAK_NSM },
324 { 0x17DB, 0x0000, WEAK_ET },
325 { 0x1800, 0x180A, NEUTRAL_ON },
326 { 0x180B, 0x180D, WEAK_NSM },
327 { 0x180E, 0x0000, WEAK_BN },
328 { 0x18A9, 0x0000, WEAK_NSM },
329 { 0x1FBD, 0x0000, NEUTRAL_ON },
330 { 0x1FBF, 0x1FC1, NEUTRAL_ON },
331 { 0x1FCD, 0x1FCF, NEUTRAL_ON },
332 { 0x1FDD, 0x1FDF, NEUTRAL_ON },
333 { 0x1FED, 0x1FEF, NEUTRAL_ON },
334 { 0x1FFD, 0x1FFE, NEUTRAL_ON },
335 { 0x2000, 0x200A, NEUTRAL_WS },
336 { 0x200B, 0x200D, WEAK_BN },
337 { 0x200F, 0x0000, STRONG_R },
338 { 0x2010, 0x2027, NEUTRAL_ON },
339 { 0x2028, 0x0000, NEUTRAL_WS },
340 { 0x2029, 0x0000, NEUTRAL_B },
341 { 0x202A, 0x0000, LRE },
342 { 0x202B, 0x0000, RLE },
343 { 0x202C, 0x0000, PDF },
344 { 0x202D, 0x0000, LRO },
345 { 0x202E, 0x0000, RLO },
346 { 0x202F, 0x0000, NEUTRAL_WS },
347 { 0x2030, 0x2034, WEAK_ET },
348 { 0x2035, 0x2057, NEUTRAL_ON },
349 { 0x205F, 0x0000, NEUTRAL_WS },
350 { 0x2060, 0x206F, WEAK_BN },
351 { 0x2070, 0x0000, WEAK_EN },
352 { 0x2074, 0x2079, WEAK_EN },
353 { 0x207A, 0x207B, WEAK_ET },
354 { 0x207C, 0x207E, NEUTRAL_ON },
355 { 0x2080, 0x2089, WEAK_EN },
356 { 0x208A, 0x208B, WEAK_ET },
357 { 0x208C, 0x208E, NEUTRAL_ON },
358 { 0x20A0, 0x20B1, WEAK_ET },
359 { 0x20D0, 0x20EA, WEAK_NSM },
360 { 0x2100, 0x2101, NEUTRAL_ON },
361 { 0x2103, 0x2106, NEUTRAL_ON },
362 { 0x2108, 0x2109, NEUTRAL_ON },
363 { 0x2114, 0x0000, NEUTRAL_ON },
364 { 0x2116, 0x2118, NEUTRAL_ON },
365 { 0x211E, 0x2123, NEUTRAL_ON },
366 { 0x2125, 0x0000, NEUTRAL_ON },
367 { 0x2127, 0x0000, NEUTRAL_ON },
368 { 0x2129, 0x0000, NEUTRAL_ON },
369 { 0x212E, 0x0000, WEAK_ET },
370 { 0x2132, 0x0000, NEUTRAL_ON },
371 { 0x213A, 0x0000, NEUTRAL_ON },
372 { 0x2140, 0x2144, NEUTRAL_ON },
373 { 0x214A, 0x215F, NEUTRAL_ON },
374 { 0x2190, 0x2211, NEUTRAL_ON },
375 { 0x2212, 0x2213, WEAK_ET },
376 { 0x2214, 0x2335, NEUTRAL_ON },
377 { 0x237B, 0x2394, NEUTRAL_ON },
378 { 0x2396, 0x244A, NEUTRAL_ON },
379 { 0x2460, 0x249B, WEAK_EN },
380 { 0x24EA, 0x0000, WEAK_EN },
381 { 0x24EB, 0x2FFB, NEUTRAL_ON },
382 { 0x3000, 0x0000, NEUTRAL_WS },
383 { 0x3001, 0x3004, NEUTRAL_ON },
384 { 0x3008, 0x3020, NEUTRAL_ON },
385 { 0x302A, 0x302F, WEAK_NSM },
386 { 0x3030, 0x0000, NEUTRAL_ON },
387 { 0x3036, 0x3037, NEUTRAL_ON },
388 { 0x303D, 0x303F, NEUTRAL_ON },
389 { 0x3099, 0x309A, WEAK_NSM },
390 { 0x309B, 0x309C, NEUTRAL_ON },
391 { 0x30A0, 0x0000, NEUTRAL_ON },
392 { 0x30FB, 0x0000, NEUTRAL_ON },
393 { 0x3251, 0x325F, NEUTRAL_ON },
394 { 0x32B1, 0x32BF, NEUTRAL_ON },
395 { 0xA490, 0xA4C6, NEUTRAL_ON },
396 { 0xFB1D, 0x0000, STRONG_R },
397 { 0xFB1E, 0x0000, WEAK_NSM },
398 { 0xFB1F, 0xFB28, STRONG_R },
399 { 0xFB29, 0x0000, WEAK_ET },
400 { 0xFB2A, 0xFB4F, STRONG_R },
401 { 0xFB50, 0xFD3D, STRONG_AL },
402 { 0xFD3E, 0xFD3F, NEUTRAL_ON },
403 { 0xFD50, 0xFDFC, STRONG_AL },
404 { 0xFE00, 0xFE23, WEAK_NSM },
405 { 0xFE30, 0xFE4F, NEUTRAL_ON },
406 { 0xFE50, 0x0000, WEAK_CS },
407 { 0xFE51, 0x0000, NEUTRAL_ON },
408 { 0xFE52, 0x0000, WEAK_CS },
409 { 0xFE54, 0x0000, NEUTRAL_ON },
410 { 0xFE55, 0x0000, WEAK_CS },
411 { 0xFE56, 0xFE5E, NEUTRAL_ON },
412 { 0xFE5F, 0x0000, WEAK_ET },
413 { 0xFE60, 0xFE61, NEUTRAL_ON },
414 { 0xFE62, 0xFE63, WEAK_ET },
415 { 0xFE64, 0xFE68, NEUTRAL_ON },
416 { 0xFE69, 0xFE6A, WEAK_ET },
417 { 0xFE6B, 0x0000, NEUTRAL_ON },
418 { 0xFE70, 0xFEFC, STRONG_AL },
419 { 0xFEFF, 0x0000, WEAK_BN },
420 { 0xFF01, 0xFF02, NEUTRAL_ON },
421 { 0xFF03, 0xFF05, WEAK_ET },
422 { 0xFF06, 0xFF0A, NEUTRAL_ON },
423 { 0xFF0B, 0x0000, WEAK_ET },
424 { 0xFF0C, 0x0000, WEAK_CS },
425 { 0xFF0D, 0x0000, WEAK_ET },
426 { 0xFF0E, 0x0000, WEAK_CS },
427 { 0xFF0F, 0x0000, WEAK_ES },
428 { 0xFF10, 0xFF19, WEAK_EN },
429 { 0xFF1A, 0x0000, WEAK_CS },
430 { 0xFF1B, 0xFF20, NEUTRAL_ON },
431 { 0xFF3B, 0xFF40, NEUTRAL_ON },
432 { 0xFF5B, 0xFF65, NEUTRAL_ON },
433 { 0xFFE0, 0xFFE1, WEAK_ET },
434 { 0xFFE2, 0xFFE4, NEUTRAL_ON },
435 { 0xFFE5, 0xFFE6, WEAK_ET },
436 { 0xFFE8, 0xFFEE, NEUTRAL_ON },
437 { 0xFFF9, 0xFFFB, WEAK_BN },
438 { 0xFFFC, 0xFFFD, NEUTRAL_ON },
439 { 0x1D167, 0x1D169, WEAK_NSM },
440 { 0x1D173, 0x1D17A, WEAK_BN },
441 { 0x1D17B, 0x1D182, WEAK_NSM },
442 { 0x1D185, 0x1D18B, WEAK_NSM },
443 { 0x1D1AA, 0x1D1AD, WEAK_NSM },
444 { 0x1D7CE, 0x1D7FF, WEAK_EN },
445 { 0xE0001, 0xE007F, WEAK_BN } };
446 int i;
447
448 bidi_type_table = Fmake_char_table (Qnil, make_number (STRONG_L));
449
450 for (i = 0; i < sizeof bidi_type / sizeof bidi_type[0]; i++)
451 char_table_set_range (bidi_type_table, bidi_type[i].from, bidi_type[i].to,
452 make_number (bidi_type[i].type));
453 bidi_initialized = 1;
454}
455
456static int
457bidi_is_arabic_number (int ch)
458{
459#ifdef TEST_STANDALONE
460 return ch >= '6' && ch <= '9';
461#else
462 return 0; /* FIXME! */
463#endif
464}
465
466/* Return the bidi type of a character CH. */
467bidi_type_t
468bidi_get_type (int ch)
469{
470 return (bidi_type_t) XINT (CHAR_TABLE_REF (bidi_type_table, ch));
471}
472
473/* Given a bidi TYPE of a character, return its category. */
474bidi_category_t
475bidi_get_category (bidi_type_t type)
476{
477 switch (type)
478 {
479 case UNKNOWN_BT:
480 return UNKNOWN_BC;
481 case STRONG_L:
482 case STRONG_R:
483 case STRONG_AL:
484 case LRE:
485 case LRO:
486 case RLE:
487 case RLO:
488 return STRONG;
489 case PDF: /* ??? really?? */
490 case WEAK_EN:
491 case WEAK_ES:
492 case WEAK_ET:
493 case WEAK_AN:
494 case WEAK_CS:
495 case WEAK_NSM:
496 case WEAK_BN:
497 return WEAK;
498 case NEUTRAL_B:
499 case NEUTRAL_S:
500 case NEUTRAL_WS:
501 case NEUTRAL_ON:
502 return NEUTRAL;
503 default:
504 abort ();
505 }
506}
507
508/* FIXME: exceedingly temporary! Should consult the Unicode database
509 of character properties. */
510int
511bidi_mirror_char (int c)
512{
513 static const char mirrored_pairs[] = "()<>[]{}";
514 const char *p = strchr (mirrored_pairs, c);
515
516 if (p)
517 {
518 size_t i = p - mirrored_pairs;
519
520 if ((i & 1) == 0)
521 return mirrored_pairs[i + 1];
522 else
523 return mirrored_pairs[i - 1];
524 }
525 return c;
526}
527
528/* Copy the bidi iterator from FROM to TO. To save cycles, this only
529 copies the part of the level stack that is actually in use. */
530static inline void
531bidi_copy_it (struct bidi_it *to, struct bidi_it *from)
532{
533 int i;
534
535 /* Copy everything except the level stack. */
536 memcpy (to, from, ((int)&((struct bidi_it *)0)->level_stack[0]));
537
538 /* Copy the active part of the level stack. */
539 to->level_stack[0] = from->level_stack[0]; /* level zero is always in use */
540 for (i = 1; i <= from->stack_idx; i++)
541 to->level_stack[i] = from->level_stack[i];
542}
543
544/* Caching the bidi iterator states. */
545
546static struct bidi_it bidi_cache[1000]; /* FIXME: make this dynamically allocated! */
547static int bidi_cache_idx;
548static int bidi_cache_last_idx;
549
550static inline void
551bidi_cache_reset (void)
552{
553 bidi_cache_idx = 0;
554 bidi_cache_last_idx = -1;
555}
556
557static inline void
558bidi_cache_fetch_state (int idx, struct bidi_it *bidi_it)
559{
560 int current_scan_dir = bidi_it->scan_dir;
561
562 if (idx < 0 || idx >= bidi_cache_idx)
563 abort ();
564
565 bidi_copy_it (bidi_it, &bidi_cache[idx]);
566 bidi_it->scan_dir = current_scan_dir;
567 bidi_cache_last_idx = idx;
568}
569
570/* Find a cached state with a given CHARPOS and resolved embedding
571 level less or equal to LEVEL. if LEVEL is -1, disregard the
572 resolved levels in cached states. DIR, if non-zero, means search
573 in that direction from the last cache hit. */
574static inline int
575bidi_cache_search (int charpos, int level, int dir)
576{
577 int i, i_start;
578
579 if (bidi_cache_idx)
580 {
581 if (charpos < bidi_cache[bidi_cache_last_idx].charpos)
582 dir = -1;
583 else if (charpos > bidi_cache[bidi_cache_last_idx].charpos)
584 dir = 1;
585 if (dir)
586 i_start = bidi_cache_last_idx;
587 else
588 {
589 dir = -1;
590 i_start = bidi_cache_idx - 1;
591 }
592
593 if (dir < 0)
594 {
595 /* Linear search for now; FIXME! */
596 for (i = i_start; i >= 0; i--)
597 if (bidi_cache[i].charpos == charpos
598 && (level == -1 || bidi_cache[i].resolved_level <= level))
599 return i;
600 }
601 else
602 {
603 for (i = i_start; i < bidi_cache_idx; i++)
604 if (bidi_cache[i].charpos == charpos
605 && (level == -1 || bidi_cache[i].resolved_level <= level))
606 return i;
607 }
608 }
609
610 return -1;
611}
612
613/* Find a cached state where the resolved level changes to a value
614 that is lower than LEVEL, and return its cache slot index. DIR is
615 the direction to search, starting with the last used cache slot.
616 BEFORE, if non-zero, means return the index of the slot that is
617 ``before'' the level change in the search direction. That is,
618 given the cached levels like this:
619
620 1122333442211
621 AB C
622
623 and assuming we are at the position cached at the slot marked with
624 C, searching backwards (DIR = -1) for LEVEL = 2 will return the
625 index of slot B or A, depending whether BEFORE is, respectively,
626 non-zero or zero. */
627static int
628bidi_cache_find_level_change (int level, int dir, int before)
629{
630 if (bidi_cache_idx)
631 {
632 int i = dir ? bidi_cache_last_idx : bidi_cache_idx - 1;
633 int incr = before ? 1 : 0;
634
635 if (!dir)
636 dir = -1;
637 else if (!incr)
638 i += dir;
639
640 if (dir < 0)
641 {
642 while (i >= incr)
643 {
644 if (bidi_cache[i - incr].resolved_level >= 0
645 && bidi_cache[i - incr].resolved_level < level)
646 return i;
647 i--;
648 }
649 }
650 else
651 {
652 while (i < bidi_cache_idx - incr)
653 {
654 if (bidi_cache[i + incr].resolved_level >= 0
655 && bidi_cache[i + incr].resolved_level < level)
656 return i;
657 i++;
658 }
659 }
660 }
661
662 return -1;
663}
664
665static inline void
666bidi_cache_iterator_state (struct bidi_it *bidi_it, int resolved)
667{
668 int idx;
669
670 /* We should never cache on backward scans. */
671 if (bidi_it->scan_dir == -1)
672 abort ();
673 idx = bidi_cache_search (bidi_it->charpos, -1, 1);
674
675 if (idx < 0)
676 {
677 idx = bidi_cache_idx;
678 if (idx > sizeof (bidi_cache) / sizeof (bidi_cache[0]) - 1)
679 abort ();
680 bidi_copy_it (&bidi_cache[idx], bidi_it);
681 if (!resolved)
682 bidi_cache[idx].resolved_level = -1;
683 }
684 else
685 {
686 /* Copy only the members which could have changed, to avoid
687 costly copying of the entire struct. */
688 bidi_cache[idx].type = bidi_it->type;
689 bidi_cache[idx].orig_type = bidi_it->orig_type;
690 if (resolved)
691 bidi_cache[idx].resolved_level = bidi_it->resolved_level;
692 else
693 bidi_cache[idx].resolved_level = -1;
694 bidi_cache[idx].invalid_levels = bidi_it->invalid_levels;
695 bidi_cache[idx].invalid_rl_levels = bidi_it->invalid_rl_levels;
696 bidi_cache[idx].next_for_neutral = bidi_it->next_for_neutral;
697 bidi_cache[idx].next_for_ws = bidi_it->next_for_ws;
698 bidi_cache[idx].ignore_bn_limit = bidi_it->ignore_bn_limit;
699 }
700
701 bidi_cache_last_idx = idx;
702 if (idx >= bidi_cache_idx)
703 bidi_cache_idx = idx + 1;
704}
705
706static inline bidi_type_t
707bidi_cache_find (int charpos, int level, struct bidi_it *bidi_it)
708{
709 int i = bidi_cache_search (charpos, level, bidi_it->scan_dir);
710
711 if (i >= 0)
712 {
713 bidi_dir_t current_scan_dir = bidi_it->scan_dir;
714
715 *bidi_it = bidi_cache[i];
716 bidi_cache_last_idx = i;
717 /* Don't let scan direction from from the cached state override
718 the current scan direction. */
719 bidi_it->scan_dir = current_scan_dir;
720 return bidi_it->type;
721 }
722
723 return UNKNOWN_BT;
724}
725
726static inline int
727bidi_peek_at_next_level (struct bidi_it *bidi_it)
728{
729 if (bidi_cache_idx == 0 || bidi_cache_last_idx == -1)
730 abort ();
731 return bidi_cache[bidi_cache_last_idx + bidi_it->scan_dir].resolved_level;
732}
733
734/* Return non-zero if buffer's byte position POS is the last character
735 of a paragraph. THIS_CH is the character preceding the one at POS in
736 the buffer. */
737int
738bidi_at_paragraph_end (int this_ch, int pos)
739{
740 int next_ch = FETCH_CHAR (pos);
741
742 /* FIXME: This should support all Unicode characters that can end a
743 paragraph. */
744 return (this_ch == '\n' && next_ch == '\n') || this_ch == BIDI_EOB;
745}
746
747/* Determine the start-of-run (sor) directional type given the two
748 embedding levels on either side of the run boundary. Also, update
749 the saved info about previously seen characters, since that info is
750 generally valid for a single level run. */
751static inline void
752bidi_set_sor_type (struct bidi_it *bidi_it, int level_before, int level_after)
753{
754 int higher_level = level_before > level_after ? level_before : level_after;
755
756 /* The prev_was_pdf gork is required for when we have several PDFs
757 in a row. In that case, we want to compute the sor type for the
758 next level run only once: when we see the first PDF. That's
759 because the sor type depends only on the higher of the two levels
760 that we find on the two sides of the level boundary (see UAX#9,
761 clause X10), and so we don't need to know the final embedding
762 level to which we descend after processing all the PDFs. */
763 if (level_before < level_after || !bidi_it->prev_was_pdf)
764 /* FIXME: should the default sor direction be user selectable? */
765 bidi_it->sor = (higher_level & 1) != 0 ? R2L : L2R;
766 if (level_before > level_after)
767 bidi_it->prev_was_pdf = 1;
768
769 bidi_it->prev.type = UNKNOWN_BT;
770 bidi_it->last_strong.type = bidi_it->last_strong.orig_type =
771 bidi_it->last_strong.pristine_type = UNKNOWN_BT;
772 bidi_it->prev_for_neutral.type = bidi_it->sor == R2L ? STRONG_R : STRONG_L;
773 bidi_it->prev_for_neutral.charpos = bidi_it->charpos;
774 bidi_it->prev_for_neutral.bytepos = bidi_it->bytepos;
775 bidi_it->next_for_neutral.type = bidi_it->next_for_neutral.orig_type =
776 bidi_it->next_for_neutral.pristine_type = UNKNOWN_BT;
777 bidi_it->ignore_bn_limit = 0; /* meaning it's unknown */
778}
779
780void
781bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it)
782{
783 bidi_it->level_stack[0].level = 0;
784 if (dir == R2L)
785 bidi_it->level_stack[0].level = 1;
786 else if (dir == NEUTRAL_DIR) /* P2 */
787 {
788 bidi_type_t type;
789 int pos = bidi_it->charpos, bytepos = bidi_it->bytepos;
790 int ch;
791
792 if (pos < 0)
793 pos = bytepos = 0;
794 else if (bidi_it->ch != BIDI_EOB)
795 {
796 pos++;
797 bytepos += bidi_it->ch_len;
798 }
799
800 ch = FETCH_CHAR (bytepos);
801 pos++;
802 bytepos += CHAR_BYTES (ch);
803
804 /* FIXME: should actually go to where the paragraph begins and
805 start the loop below from there, since UAX#9 says to find the
806 first strong directional character in the paragraph. */
807
808 for (type = bidi_get_type (ch);
809 /* NOTE: UAX#9 says to search only for L, AL, or R types of
810 characters, and ignore RLE, RLO, LRE, and LRO. However,
811 I'm not sure it makes sense to omit those 4; should try
812 with and without that to see the effect. */
813 (bidi_get_category (type) != STRONG)
814 || (bidi_ignore_explicit_marks_for_paragraph_level
815 && (type == RLE || type == RLO
816 || type == LRE || type == LRO));
817 type = bidi_get_type (ch))
818 {
819 if (type == NEUTRAL_B || bidi_at_paragraph_end (ch, bytepos))
820 break;
821 FETCH_CHAR_ADVANCE (ch, pos, bytepos);
822 }
823 if (type == STRONG_R || type == STRONG_AL) /* P3 */
824 bidi_it->level_stack[0].level = 1;
825 }
826 bidi_it->scan_dir = 1; /* FIXME: do we need to have control on this? */
827 bidi_it->resolved_level = bidi_it->level_stack[0].level;
828 bidi_it->level_stack[0].override = NEUTRAL_DIR; /* X1 */
829 bidi_it->invalid_levels = 0;
830 bidi_it->invalid_rl_levels = -1;
831 bidi_it->new_paragraph = 0;
832 bidi_it->next_en_pos = -1;
833 bidi_it->next_for_ws.type = UNKNOWN_BT;
834 bidi_set_sor_type (bidi_it, bidi_it->level_stack[0].level, 0); /* X10 */
835
836 bidi_cache_reset ();
837}
838
839/* Do whatever UAX#9 clause X8 says should be done at paragraph's end,
840 and set the new paragraph flag in the iterator. */
841static inline void
842bidi_set_paragraph_end (struct bidi_it *bidi_it)
843{
844 bidi_it->invalid_levels = 0;
845 bidi_it->invalid_rl_levels = -1;
846 bidi_it->stack_idx = 0;
847 bidi_it->resolved_level = bidi_it->level_stack[0].level;
848 bidi_it->new_paragraph = 1;
849}
850
851/* Initialize the bidi iterator from buffer position POS for paragraph
852 direction DIR. Return the embedding level at POS. */
853void
854bidi_init_it (int pos, bidi_dir_t dir, struct bidi_it *bidi_it)
855{
856 if (! bidi_initialized)
857 bidi_initialize ();
858 bidi_set_paragraph_end (bidi_it);
859 bidi_it->charpos = pos;
860 if (pos <= 0)
861 {
862 bidi_it->bytepos = bidi_it->charpos;
863 bidi_it->ch_len = 1; /* so that incrementing bytepos works */
864 }
865 else
866 {
867 bidi_it->bytepos = CHAR_TO_BYTE (pos);
868 bidi_it->ch_len
869 = MULTIBYTE_FORM_LENGTH (BYTE_POS_ADDR (bidi_it->bytepos),
870 MAX_MULTIBYTE_LENGTH);
871 }
872 bidi_it->ch = '\x1d'; /* FIXME: should be U+2029 */
873 bidi_it->type = NEUTRAL_B;
874 bidi_it->orig_type = UNKNOWN_BT;
875 bidi_it->pristine_type = UNKNOWN_BT;
876 bidi_it->prev_was_pdf = 0;
877 bidi_it->prev.type = bidi_it->prev.orig_type = UNKNOWN_BT;
878 bidi_it->last_strong.type = bidi_it->last_strong.orig_type =
879 bidi_it->last_strong.pristine_type = UNKNOWN_BT;
880 bidi_it->next_for_neutral.charpos = -1;
881 bidi_it->next_for_neutral.type =
882 bidi_it->next_for_neutral.orig_type =
883 bidi_it->next_for_neutral.pristine_type = UNKNOWN_BT;
884 bidi_it->prev_for_neutral.charpos = -1;
885 bidi_it->prev_for_neutral.type =
886 bidi_it->prev_for_neutral.orig_type =
887 bidi_it->prev_for_neutral.pristine_type = UNKNOWN_BT;
888 bidi_it->sor = L2R; /* FIXME: should it be user-selectable? */
889 bidi_paragraph_init (dir, bidi_it);
890}
891
892/* Push the current embedding level and override status; reset the
893 current level to LEVEL and the current override status to OVERRIDE. */
894static inline void
895bidi_push_embedding_level (struct bidi_it *bidi_it,
896 int level, bidi_dir_t override)
897{
898 bidi_it->stack_idx++;
899 if (bidi_it->stack_idx >= BIDI_MAXLEVEL)
900 abort ();
901 bidi_it->level_stack[bidi_it->stack_idx].level = level;
902 bidi_it->level_stack[bidi_it->stack_idx].override = override;
903}
904
905/* Pop the embedding level and directional override status from the
906 stack, and return the new level. */
907static inline int
908bidi_pop_embedding_level (struct bidi_it *bidi_it)
909{
910 /* UAX#9 says to ignore invalid PDFs. */
911 if (bidi_it->stack_idx > 0)
912 bidi_it->stack_idx--;
913 return bidi_it->level_stack[bidi_it->stack_idx].level;
914}
915
916/* Record in SAVED_INFO the information about the current character. */
917static inline void
918bidi_remember_char (struct bidi_saved_info *saved_info,
919 struct bidi_it *bidi_it)
920{
921 saved_info->charpos = bidi_it->charpos;
922 saved_info->bytepos = bidi_it->bytepos;
923 saved_info->type = bidi_it->type;
924 saved_info->orig_type = bidi_it->orig_type;
925 saved_info->pristine_type = bidi_it->pristine_type;
926}
927
928/* Resolve the type of a neutral character according to the type of
929 surrounding strong text and the current embedding level. */
930static inline bidi_type_t
931bidi_resolve_neutral_1 (bidi_type_t prev_type, bidi_type_t next_type, int lev)
932{
933 /* N1: European and Arabic numbers are treated as though they were R. */
934 if (next_type == WEAK_EN || next_type == WEAK_AN)
935 next_type = STRONG_R;
936 if (prev_type == WEAK_EN || prev_type == WEAK_AN)
937 prev_type = STRONG_R;
938
939 if (next_type == prev_type) /* N1 */
940 return next_type;
941 else if ((lev & 1) == 0) /* N2 */
942 return STRONG_L;
943 else
944 return STRONG_R;
945}
946
947static inline int
948bidi_explicit_dir_char (int c)
949{
950 /* FIXME: this should be replaced with a lookup table with suitable
951 bits set, like standard C ctype macros do. */
952 return (c == LRE_CHAR || c == LRO_CHAR
953 || c == RLE_CHAR || c == RLO_CHAR || c == PDF_CHAR);
954}
955
956/* A helper function for bidi_resolve_explicit. It advances to the
957 next character in logical order and determines the new embedding
958 level and directional override, but does not take into account
959 empty embeddings. */
960static int
961bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
962{
963 int curchar;
964 bidi_type_t type;
965 int current_level;
966 int new_level;
967 bidi_dir_t override;
968
969 if (bidi_it->charpos < 0)
970 bidi_it->charpos = bidi_it->bytepos = 0;
971 else
972 {
973 bidi_it->charpos++;
974 bidi_it->bytepos += bidi_it->ch_len;
975 }
976
977 current_level = bidi_it->level_stack[bidi_it->stack_idx].level; /* X1 */
978 override = bidi_it->level_stack[bidi_it->stack_idx].override;
979 new_level = current_level;
980
981 /* in case it is a unibyte character (not yet implemented) */
982 /* _fetch_multibyte_char_len = 1; */
983 curchar = FETCH_CHAR (bidi_it->bytepos);
984 bidi_it->ch = curchar;
985 bidi_it->ch_len = CHAR_BYTES (curchar);
986
987 type = bidi_get_type (curchar);
988 bidi_it->pristine_type = type;
989
990 if (type != PDF)
991 bidi_it->prev_was_pdf = 0;
992
993 bidi_it->orig_type = UNKNOWN_BT;
994
995 switch (type)
996 {
997 case RLE: /* X2 */
998 case RLO: /* X4 */
999 bidi_it->orig_type = type;
1000 type = WEAK_BN; /* X9/Retaining */
1001 if (bidi_it->ignore_bn_limit <= 0)
1002 {
1003 if (current_level <= BIDI_MAXLEVEL - 4)
1004 {
1005 /* Compute the least odd embedding level greater than
1006 the current level. */
1007 new_level = ((current_level + 1) & ~1) + 1;
1008 if (bidi_it->orig_type == RLE)
1009 override = NEUTRAL_DIR;
1010 else
1011 override = R2L;
1012 if (current_level == BIDI_MAXLEVEL - 4)
1013 bidi_it->invalid_rl_levels = 0;
1014 bidi_push_embedding_level (bidi_it, new_level, override);
1015 }
1016 else
1017 {
1018 bidi_it->invalid_levels++;
1019 /* See the commentary about invalid_rl_levels below. */
1020 if (bidi_it->invalid_rl_levels < 0)
1021 bidi_it->invalid_rl_levels = 0;
1022 bidi_it->invalid_rl_levels++;
1023 }
1024 }
1025 else if (bidi_it->prev.orig_type == WEAK_EN /* W5/Retaining */
1026 || bidi_it->next_en_pos > bidi_it->charpos)
1027 type = WEAK_EN;
1028 break;
1029 case LRE: /* X3 */
1030 case LRO: /* X5 */
1031 bidi_it->orig_type = type;
1032 type = WEAK_BN; /* X9/Retaining */
1033 if (bidi_it->ignore_bn_limit <= 0)
1034 {
1035 if (current_level <= BIDI_MAXLEVEL - 5)
1036 {
1037 /* Compute the least even embedding level greater than
1038 the current level. */
1039 new_level = ((current_level + 2) & ~1);
1040 if (bidi_it->orig_type == LRE)
1041 override = NEUTRAL_DIR;
1042 else
1043 override = L2R;
1044 bidi_push_embedding_level (bidi_it, new_level, override);
1045 }
1046 else
1047 {
1048 bidi_it->invalid_levels++;
1049 /* invalid_rl_levels counts invalid levels encountered
1050 while the embedding level was already too high for
1051 LRE/LRO, but not for RLE/RLO. That is because
1052 there may be exactly one PDF which we should not
1053 ignore even though invalid_levels is non-zero.
1054 invalid_rl_levels helps to know what PDF is
1055 that. */
1056 if (bidi_it->invalid_rl_levels >= 0)
1057 bidi_it->invalid_rl_levels++;
1058 }
1059 }
1060 else if (bidi_it->prev.orig_type == WEAK_EN /* W5/Retaining */
1061 || bidi_it->next_en_pos > bidi_it->charpos)
1062 type = WEAK_EN;
1063 break;
1064 case PDF: /* X7 */
1065 bidi_it->orig_type = type;
1066 type = WEAK_BN; /* X9/Retaining */
1067 if (bidi_it->ignore_bn_limit <= 0)
1068 {
1069 if (!bidi_it->invalid_rl_levels)
1070 {
1071 new_level = bidi_pop_embedding_level (bidi_it);
1072 bidi_it->invalid_rl_levels = -1;
1073 if (bidi_it->invalid_levels)
1074 bidi_it->invalid_levels--;
1075 /* else nothing: UAX#9 says to ignore invalid PDFs */
1076 }
1077 if (!bidi_it->invalid_levels)
1078 new_level = bidi_pop_embedding_level (bidi_it);
1079 else
1080 {
1081 bidi_it->invalid_levels--;
1082 bidi_it->invalid_rl_levels--;
1083 }
1084 }
1085 else if (bidi_it->prev.orig_type == WEAK_EN /* W5/Retaining */
1086 || bidi_it->next_en_pos > bidi_it->charpos)
1087 type = WEAK_EN;
1088 break;
1089 default:
1090 /* Nothing. */
1091 break;
1092 }
1093
1094 bidi_it->type = type;
1095
1096 return new_level;
1097}
1098
1099/* Given an iterator state in BIDI_IT, advance one character position
1100 in the buffer to the next character (in the logical order), resolve
1101 any explicit embeddings and directional overrides, and return the
1102 embedding level of the character after resolving explicit
1103 directives and ignoring empty embeddings. */
1104static int
1105bidi_resolve_explicit (struct bidi_it *bidi_it)
1106{
1107 int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level;
1108 int new_level = bidi_resolve_explicit_1 (bidi_it);
1109
1110 if (prev_level < new_level
1111 && bidi_it->type == WEAK_BN
1112 && bidi_it->ignore_bn_limit == 0 /* only if not already known */
1113 && bidi_explicit_dir_char (FETCH_CHAR (bidi_it->bytepos
1114 + bidi_it->ch_len)))
1115 {
1116 /* Avoid pushing and popping embedding levels if the level run
1117 is empty, as this breaks level runs where it shouldn't.
1118 UAX#9 removes all the explicit embedding and override codes,
1119 so empty embeddings disappear without a trace. We need to
1120 behave as if we did the same. */
1121 struct bidi_it saved_it;
1122 int level = prev_level;
1123
1124 bidi_copy_it (&saved_it, bidi_it);
1125
1126 while (bidi_explicit_dir_char (FETCH_CHAR (bidi_it->bytepos
1127 + bidi_it->ch_len)))
1128 {
1129 level = bidi_resolve_explicit_1 (bidi_it);
1130 }
1131
1132 if (level == prev_level) /* empty embedding */
1133 saved_it.ignore_bn_limit = bidi_it->charpos + 1;
1134 else /* this embedding is non-empty */
1135 saved_it.ignore_bn_limit = -1;
1136
1137 bidi_copy_it (bidi_it, &saved_it);
1138 if (bidi_it->ignore_bn_limit > 0)
1139 {
1140 /* We pushed a level, but we shouldn't have. Undo that. */
1141 if (!bidi_it->invalid_rl_levels)
1142 {
1143 new_level = bidi_pop_embedding_level (bidi_it);
1144 bidi_it->invalid_rl_levels = -1;
1145 if (bidi_it->invalid_levels)
1146 bidi_it->invalid_levels--;
1147 }
1148 if (!bidi_it->invalid_levels)
1149 new_level = bidi_pop_embedding_level (bidi_it);
1150 else
1151 {
1152 bidi_it->invalid_levels--;
1153 bidi_it->invalid_rl_levels--;
1154 }
1155 }
1156 }
1157
1158 /* For when the paragraph end is defined by anything other than a
1159 special Unicode character (a.k.a. ``higher protocols''). */
1160 if (bidi_it->type != NEUTRAL_B)
1161 if (bidi_at_paragraph_end (bidi_it->ch,
1162 bidi_it->bytepos + bidi_it->ch_len))
1163 bidi_it->type = NEUTRAL_B;
1164
1165 if (bidi_it->type == NEUTRAL_B) /* X8 */
1166 {
1167 bidi_set_paragraph_end (bidi_it);
1168 bidi_it->orig_type = bidi_it->type; /* needed below and in L1 */
1169 }
1170
1171 return new_level;
1172}
1173
1174/* Advance in the buffer, resolve weak types and return the type of
1175 the next character after weak type resolution. */
1176bidi_type_t
1177bidi_resolve_weak (struct bidi_it *bidi_it)
1178{
1179 bidi_type_t type;
1180 bidi_dir_t override;
1181 int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level;
1182 int new_level = bidi_resolve_explicit (bidi_it);
1183 int next_char;
1184 bidi_type_t type_of_next;
1185 struct bidi_it saved_it;
1186
1187 type = bidi_it->type;
1188 override = bidi_it->level_stack[bidi_it->stack_idx].override;
1189
1190 if (type == UNKNOWN_BT
1191 || type == LRE
1192 || type == LRO
1193 || type == RLE
1194 || type == RLO
1195 || type == PDF)
1196 abort ();
1197
1198 if (new_level != prev_level
1199 || bidi_it->type == NEUTRAL_B)
1200 {
1201 /* We've got a new embedding level run, compute the directional
1202 type of sor and initialize per-run variables (UAX#9, clause
1203 X10). */
1204 bidi_set_sor_type (bidi_it, prev_level, new_level);
1205 }
1206 else if (type == NEUTRAL_S || type == NEUTRAL_WS
1207 || type == WEAK_BN || type == STRONG_AL)
1208 bidi_it->orig_type = type; /* needed in L1 */
1209
1210 /* Level and directional override status are already recorded in
1211 bidi_it, and do not need any change; see X6. */
1212 if (override == R2L) /* X6 */
1213 type = STRONG_R;
1214 else if (override == L2R)
1215 type = STRONG_L;
1216 else if (type == STRONG_AL)
1217 type = STRONG_R; /* W3 */
1218 else if (type == WEAK_NSM) /* W1 */
1219 {
1220 /* Note that we don't need to consider the case where the prev
1221 character has its type overridden by an RLO or LRO: such
1222 characters are outside the current level run, and thus not
1223 relevant to this NSM. Thus, NSM gets the pristine_type of
1224 the previous character. */
1225 if (bidi_it->prev.type != UNKNOWN_BT)
1226 type = bidi_it->prev.pristine_type;
1227 else if (bidi_it->sor == R2L)
1228 type = STRONG_R;
1229 else if (bidi_it->sor == L2R)
1230 type = STRONG_L;
1231 else /* shouldn't happen! */
1232 abort ();
1233 if (type == WEAK_EN /* W2 after W1 */
1234 && bidi_it->last_strong.orig_type == STRONG_AL)
1235 type = WEAK_AN;
1236 }
1237 else if (type == WEAK_EN /* W2 */
1238 && bidi_it->last_strong.orig_type == STRONG_AL)
1239 type = WEAK_AN;
1240 else if ((type == WEAK_ES
1241 && (bidi_it->prev.orig_type == WEAK_EN /* W4 */
1242 && (bidi_it->prev.pristine_type == WEAK_EN
1243 || bidi_it->prev.pristine_type == WEAK_NSM))) /* aft W1 */
1244 || (type == WEAK_CS
1245 && ((bidi_it->prev.orig_type == WEAK_EN
1246 && (bidi_it->prev.pristine_type == WEAK_EN /* W4 */
1247 || bidi_it->prev.pristine_type == WEAK_NSM)) /* a/W1 */
1248 || bidi_it->prev.orig_type == WEAK_AN))) /* W4 */
1249 {
1250 next_char = FETCH_CHAR (bidi_it->bytepos + bidi_it->ch_len);
1251 type_of_next = bidi_get_type (next_char);
1252
1253 if (type_of_next == WEAK_BN
1254 || bidi_explicit_dir_char (next_char))
1255 {
1256 bidi_copy_it (&saved_it, bidi_it);
1257 while (bidi_resolve_explicit (bidi_it) == new_level
1258 && bidi_it->type == WEAK_BN)
1259 ;
1260 type_of_next = bidi_it->type;
1261 bidi_copy_it (bidi_it, &saved_it);
1262 }
1263
1264 /* If the next character is EN, but the last strong-type
1265 character is AL, that next EN will be changed to AN when we
1266 process it in W2 above. So in that case, this ES should not
1267 be changed into EN. */
1268 if (type == WEAK_ES
1269 && type_of_next == WEAK_EN
1270 && bidi_it->last_strong.orig_type != STRONG_AL)
1271 type = WEAK_EN;
1272 else if (type == WEAK_CS)
1273 {
1274 if (bidi_it->prev.orig_type == WEAK_AN
1275 && (type_of_next == WEAK_AN
1276 /* If the next character is EN, but the last
1277 strong-type character is AL, EN will be later
1278 changed to AN when we process it in W2 above. So
1279 in that case, this ES should not be changed into
1280 EN. */
1281 || (type_of_next == WEAK_EN
1282 && bidi_it->last_strong.orig_type == STRONG_AL)))
1283 type = WEAK_AN;
1284 else if (bidi_it->prev.orig_type == WEAK_EN
1285 && type_of_next == WEAK_EN
1286 && bidi_it->last_strong.orig_type != STRONG_AL)
1287 type = WEAK_EN;
1288 }
1289 }
1290 else if (type == WEAK_ET /* W5: ET with EN before or after it */
1291 || type == WEAK_BN) /* W5/Retaining */
1292 {
1293 if (bidi_it->prev.orig_type == WEAK_EN /* ET/BN with EN before it */
1294 || bidi_it->next_en_pos > bidi_it->charpos)
1295 type = WEAK_EN;
1296 /* W5: ET with EN after it. */
1297 else
1298 {
1299 int en_pos = bidi_it->charpos + 1;
1300
1301 next_char = FETCH_CHAR (bidi_it->bytepos + bidi_it->ch_len);
1302 type_of_next = bidi_get_type (next_char);
1303
1304 if (type_of_next == WEAK_ET
1305 || type_of_next == WEAK_BN
1306 || bidi_explicit_dir_char (next_char))
1307 {
1308 bidi_copy_it (&saved_it, bidi_it);
1309 while (bidi_resolve_explicit (bidi_it) == new_level
1310 && (bidi_it->type == WEAK_BN || bidi_it->type == WEAK_ET))
1311 ;
1312 type_of_next = bidi_it->type;
1313 en_pos = bidi_it->charpos;
1314 bidi_copy_it (bidi_it, &saved_it);
1315 }
1316 if (type_of_next == WEAK_EN)
1317 {
1318 /* If the last strong character is AL, the EN we've
1319 found will become AN when we get to it (W2). */
1320 if (bidi_it->last_strong.orig_type != STRONG_AL)
1321 {
1322 type = WEAK_EN;
1323 /* Remember this EN position, to speed up processing
1324 of the next ETs. */
1325 bidi_it->next_en_pos = en_pos;
1326 }
1327 else if (type == WEAK_BN)
1328 type = NEUTRAL_ON; /* W6/Retaining */
1329 }
1330 }
1331 }
1332
1333 if (type == WEAK_ES || type == WEAK_ET || type == WEAK_CS /* W6 */
1334 || (type == WEAK_BN && (bidi_it->prev.orig_type == WEAK_CS /* W6/Ret. */
1335 || bidi_it->prev.orig_type == WEAK_ES
1336 || bidi_it->prev.orig_type == WEAK_ET)))
1337 type = NEUTRAL_ON;
1338
1339 /* Store the type we've got so far, before we clobber it with strong
1340 types in W7 and while resolving neutral types. But leave alone
1341 the original types that were recorded above, because we will need
1342 them for the L1 clause. */
1343 if (bidi_it->orig_type == UNKNOWN_BT)
1344 bidi_it->orig_type = type;
1345
1346 if (type == WEAK_EN) /* W7 */
1347 {
1348 if ((bidi_it->last_strong.orig_type == STRONG_L)
1349 || (bidi_it->last_strong.type == UNKNOWN_BT && bidi_it->sor == L2R))
1350 type = STRONG_L;
1351 }
1352
1353 bidi_it->type = type;
1354 return type;
1355}
1356
1357bidi_type_t
1358bidi_resolve_neutral (struct bidi_it *bidi_it)
1359{
1360 int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level;
1361 bidi_type_t type = bidi_resolve_weak (bidi_it);
1362 int current_level = bidi_it->level_stack[bidi_it->stack_idx].level;
1363
1364 if (!(type == STRONG_R
1365 || type == STRONG_L
1366 || type == WEAK_BN
1367 || type == WEAK_EN
1368 || type == WEAK_AN
1369 || type == NEUTRAL_B
1370 || type == NEUTRAL_S
1371 || type == NEUTRAL_WS
1372 || type == NEUTRAL_ON))
1373 abort ();
1374
1375 if (bidi_get_category (type) == NEUTRAL
1376 || (type == WEAK_BN && prev_level == current_level))
1377 {
1378 if (bidi_it->next_for_neutral.type != UNKNOWN_BT)
1379 type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type,
1380 bidi_it->next_for_neutral.type,
1381 current_level);
1382 else
1383 {
1384 /* Arrrgh!! The UAX#9 algorithm is too deeply entrenched in
1385 the assumption of batch-style processing; see clauses W4,
1386 W5, and especially N1, which require to look far forward
1387 (as well as back) in the buffer. May the fleas of a
1388 thousand camels infest the armpits of those who design
1389 supposedly general-purpose algorithms by looking at their
1390 own implementations, and fail to consider other possible
1391 implementations! */
1392 struct bidi_it saved_it;
1393 bidi_type_t next_type;
1394
1395 if (bidi_it->scan_dir == -1)
1396 abort ();
1397
1398 bidi_copy_it (&saved_it, bidi_it);
1399 /* Scan the text forward until we find the first non-neutral
1400 character, and then use that to resolve the neutral we
1401 are dealing with now. We also cache the scanned iterator
1402 states, to salvage some of the effort later. */
1403 bidi_cache_iterator_state (bidi_it, 0);
1404 do {
1405 /* Record the info about the previous character, so that
1406 it will be cached below with this state. */
1407 if (bidi_it->orig_type != WEAK_BN /* W1/Retaining */
1408 && bidi_it->type != WEAK_BN)
1409 bidi_remember_char (&bidi_it->prev, bidi_it);
1410 type = bidi_resolve_weak (bidi_it);
1411 /* Paragraph separators have their levels fully resolved
1412 at this point, so cache them as resolved. */
1413 bidi_cache_iterator_state (bidi_it, type == NEUTRAL_B);
1414 /* FIXME: implement L1 here, by testing for a newline and
1415 resetting the level for any sequence of whitespace
1416 characters adjacent to it. */
1417 } while (!(type == NEUTRAL_B
1418 || (type != WEAK_BN
1419 && bidi_get_category (type) != NEUTRAL)
1420 /* This is all per level run, so stop when we
1421 reach the end of this level run. */
1422 || bidi_it->level_stack[bidi_it->stack_idx].level !=
1423 current_level));
1424
1425 bidi_remember_char (&saved_it.next_for_neutral, bidi_it);
1426
1427 switch (type)
1428 {
1429 case STRONG_L:
1430 case STRONG_R:
1431 case STRONG_AL:
1432 next_type = type;
1433 break;
1434 case WEAK_EN:
1435 case WEAK_AN:
1436 /* N1: ``European and Arabic numbers are treated as
1437 though they were R.'' */
1438 next_type = STRONG_R;
1439 saved_it.next_for_neutral.type = STRONG_R;
1440 break;
1441 case WEAK_BN:
1442 if (!bidi_explicit_dir_char (bidi_it->ch))
1443 abort (); /* can't happen: BNs are skipped */
1444 /* FALLTHROUGH */
1445 case NEUTRAL_B:
1446 /* Marched all the way to the end of this level run.
1447 We need to use the eor type, whose information is
1448 stored by bidi_set_sor_type in the prev_for_neutral
1449 member. */
1450 if (saved_it.type != WEAK_BN
1451 || bidi_get_category (bidi_it->prev.orig_type) == NEUTRAL)
1452 {
1453 next_type = bidi_it->prev_for_neutral.type;
1454 saved_it.next_for_neutral.type = next_type;
1455 }
1456 else
1457 {
1458 /* This is a BN which does not adjoin neutrals.
1459 Leave its type alone. */
1460 bidi_copy_it (bidi_it, &saved_it);
1461 return bidi_it->type;
1462 }
1463 break;
1464 default:
1465 abort ();
1466 }
1467 type = bidi_resolve_neutral_1 (saved_it.prev_for_neutral.type,
1468 next_type, current_level);
1469 saved_it.type = type;
1470 bidi_copy_it (bidi_it, &saved_it);
1471 }
1472 }
1473 return type;
1474}
1475
1476/* Given an iterator state in BIDI_IT, advance one character position
1477 in the buffer to the next character (in the logical order), resolve
1478 the bidi type of that next character, and return that type. */
1479bidi_type_t
1480bidi_type_of_next_char (struct bidi_it *bidi_it)
1481{
1482 bidi_type_t type;
1483
1484 /* This should always be called during a forward scan. */
1485 if (bidi_it->scan_dir != 1)
1486 abort ();
1487
1488 /* Reset the limit until which to ignore BNs if we step out of the
1489 area where we found only empty levels. */
1490 if ((bidi_it->ignore_bn_limit > 0
1491 && bidi_it->ignore_bn_limit <= bidi_it->charpos)
1492 || (bidi_it->ignore_bn_limit == -1
1493 && !bidi_explicit_dir_char (bidi_it->ch)))
1494 bidi_it->ignore_bn_limit = 0;
1495
1496 type = bidi_resolve_neutral (bidi_it);
1497
1498 return type;
1499}
1500
1501/* Given an iterator state BIDI_IT, advance one character position in
1502 the buffer to the next character (in the logical order), resolve
1503 the embedding and implicit levels of that next character, and
1504 return the resulting level. */
1505int
1506bidi_level_of_next_char (struct bidi_it *bidi_it)
1507{
1508 bidi_type_t type;
1509 int level, prev_level = -1;
1510 struct bidi_saved_info next_for_neutral;
1511
1512 if (bidi_it->scan_dir == 1)
1513 {
1514 /* There's no sense in trying to advance if we hit end of text. */
1515 if (bidi_it->ch == BIDI_EOB)
1516 return bidi_it->resolved_level;
1517
1518 /* Record the info about the previous character. */
1519 if (bidi_it->orig_type != WEAK_BN /* W1/Retaining */
1520 && bidi_it->type != WEAK_BN)
1521 bidi_remember_char (&bidi_it->prev, bidi_it);
1522 if (bidi_it->orig_type == STRONG_R || bidi_it->orig_type == STRONG_L
1523 || bidi_it->orig_type == STRONG_AL)
1524 bidi_remember_char (&bidi_it->last_strong, bidi_it);
1525 /* FIXME: it sounds like we don't need both prev and
1526 prev_for_neutral members, but I'm leaving them both for now. */
1527 if (bidi_it->type == STRONG_R || bidi_it->type == STRONG_L
1528 || bidi_it->type == WEAK_EN || bidi_it->type == WEAK_AN)
1529 bidi_remember_char (&bidi_it->prev_for_neutral, bidi_it);
1530
1531 /* If we overstepped the characters used for resolving neutrals
1532 and whitespace, invalidate their info in the iterator. */
1533 if (bidi_it->charpos >= bidi_it->next_for_neutral.charpos)
1534 bidi_it->next_for_neutral.type = UNKNOWN_BT;
1535 if (bidi_it->next_en_pos >= 0
1536 && bidi_it->charpos >= bidi_it->next_en_pos)
1537 bidi_it->next_en_pos = -1;
1538 if (bidi_it->next_for_ws.type != UNKNOWN_BT
1539 && bidi_it->charpos >= bidi_it->next_for_ws.charpos)
1540 bidi_it->next_for_ws.type = UNKNOWN_BT;
1541
1542 /* This must be taken before we fill the iterator with the info
1543 about the next char. If we scan backwards, the iterator
1544 state must be already cached, so there's no need to know the
1545 embedding level of the previous character, since we will be
1546 returning to our caller shortly. */
1547 prev_level = bidi_it->level_stack[bidi_it->stack_idx].level;
1548 }
1549 next_for_neutral = bidi_it->next_for_neutral;
1550
1551 /* Perhaps it is already cached. */
1552 type = bidi_cache_find (bidi_it->charpos + bidi_it->scan_dir, -1, bidi_it);
1553 if (type != UNKNOWN_BT)
1554 {
1555 /* Don't lose the information for resolving neutrals! The
1556 cached states could have been cached before their
1557 next_for_neutral member was computed. If we are on our way
1558 forward, we can simply take the info from the previous
1559 state. */
1560 if (bidi_it->scan_dir == 1
1561 && bidi_it->next_for_neutral.type == UNKNOWN_BT)
1562 bidi_it->next_for_neutral = next_for_neutral;
1563
1564 /* If resolved_level is -1, it means this state was cached
1565 before it was completely resolved, so we cannot return
1566 it. */
1567 if (bidi_it->resolved_level != -1)
1568 return bidi_it->resolved_level;
1569 }
1570 if (bidi_it->scan_dir == -1)
1571 /* If we are going backwards, the iterator state is already cached
1572 from previous scans, and should be fully resolved. */
1573 abort ();
1574
1575 if (type == UNKNOWN_BT)
1576 type = bidi_type_of_next_char (bidi_it);
1577
1578 if (type == NEUTRAL_B)
1579 return bidi_it->resolved_level;
1580
1581 level = bidi_it->level_stack[bidi_it->stack_idx].level;
1582 if ((bidi_get_category (type) == NEUTRAL /* && type != NEUTRAL_B */)
1583 || (type == WEAK_BN && prev_level == level))
1584 {
1585 if (bidi_it->next_for_neutral.type == UNKNOWN_BT)
1586 abort ();
1587
1588 /* If the cached state shows a neutral character, it was not
1589 resolved by bidi_resolve_neutral, so do it now. */
1590 type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type,
1591 bidi_it->next_for_neutral.type,
1592 level);
1593 }
1594
1595 if (!(type == STRONG_R
1596 || type == STRONG_L
1597 || type == WEAK_BN
1598 || type == WEAK_EN
1599 || type == WEAK_AN))
1600 abort ();
1601 bidi_it->type = type;
1602
1603 /* For L1 below, we need to know, for each WS character, whether
1604 it belongs to a sequence of WS characters preceeding a newline
1605 or a TAB or a paragraph separator. */
1606 if (bidi_it->pristine_type == NEUTRAL_WS
1607 && bidi_it->next_for_ws.type == UNKNOWN_BT)
1608 {
1609 int ch;
1610 int clen = bidi_it->ch_len;
1611 int bpos = bidi_it->bytepos;
1612 int cpos = bidi_it->charpos;
1613 bidi_type_t chtype;
1614
1615 do {
1616 /*_fetch_multibyte_char_len = 1;*/
1617 ch = FETCH_CHAR (bpos + clen);
1618 bpos += clen;
1619 cpos++;
1620 clen = CHAR_BYTES (ch);
1621 if (ch == '\n' /* || ch == LINESEP_CHAR */)
1622 chtype = NEUTRAL_B;
1623 else
1624 chtype = bidi_get_type (ch);
1625 } while (chtype == NEUTRAL_WS || chtype == WEAK_BN
1626 || bidi_explicit_dir_char (ch)); /* L1/Retaining */
1627 bidi_it->next_for_ws.type = chtype;
1628 bidi_it->next_for_ws.charpos = cpos;
1629 bidi_it->next_for_ws.bytepos = bpos;
1630 }
1631
1632 /* Resolve implicit levels, with a twist: PDFs get the embedding
1633 level of the enbedding they terminate. See below for the
1634 reason. */
1635 if (bidi_it->pristine_type == PDF
1636 /* Don't do this if this formatting code didn't change the
1637 embedding level due to invalid or empty embeddings. */
1638 && prev_level != level)
1639 {
1640 /* Don't look in UAX#9 for the reason for this: it's our own
1641 private quirk. The reason is that we want the formatting
1642 codes to be delivered so that they bracket the text of their
1643 embedding. For example, given the text
1644
1645 {RLO}teST{PDF}
1646
1647 we want it to be displayed as
1648
1649 {RLO}STet{PDF}
1650
1651 not as
1652
1653 STet{RLO}{PDF}
1654
1655 which will result because we bump up the embedding level as
1656 soon as we see the RLO and pop it as soon as we see the PDF,
1657 so RLO itself has the same embedding level as "teST", and
1658 thus would be normally delivered last, just before the PDF.
1659 The switch below fiddles with the level of PDF so that this
1660 ugly side effect does not happen.
1661
1662 (This is, of course, only important if the formatting codes
1663 are actually displayed, but Emacs does display them if the
1664 user wants to.) */
1665 level = prev_level;
1666 }
1667 else if (bidi_it->pristine_type == NEUTRAL_B /* L1 */
1668 || bidi_it->pristine_type == NEUTRAL_S
1669 || bidi_it->ch == '\n' /* || bidi_it->ch == LINESEP_CHAR */
1670 || (bidi_it->pristine_type == NEUTRAL_WS
1671 && (bidi_it->next_for_ws.type == NEUTRAL_B
1672 || bidi_it->next_for_ws.type == NEUTRAL_S)))
1673 level = bidi_it->level_stack[0].level;
1674 else if ((level & 1) == 0) /* I1 */
1675 {
1676 if (type == STRONG_R)
1677 level++;
1678 else if (type == WEAK_EN || type == WEAK_AN)
1679 level += 2;
1680 }
1681 else /* I2 */
1682 {
1683 if (type == STRONG_L || type == WEAK_EN || type == WEAK_AN)
1684 level++;
1685 }
1686
1687 bidi_it->resolved_level = level;
1688 return level;
1689}
1690
1691/* Move to the other edge of a level given by LEVEL. If END_FLAG is
1692 non-zero, we are at the end of a level, and we need to prepare to
1693 resume the scan of the lower level.
1694
1695 If this level's other edge is cached, we simply jump to it, filling
1696 the iterator structure with the iterator state on the other edge.
1697 Otherwise, we walk the buffer until we come back to the same level
1698 as LEVEL.
1699
1700 Note: we are not talking here about a ``level run'' in the UAX#9
1701 sense of the term, but rather about a ``level'' which includes
1702 all the levels higher than it. In other words, given the levels
1703 like this:
1704
1705 11111112222222333333334443343222222111111112223322111
1706 A B C
1707
1708 and assuming we are at point A scanning left to right, this
1709 function moves to point C, whereas the UAX#9 ``level 2 run'' ends
1710 at point B. */
1711static void
1712bidi_find_other_level_edge (struct bidi_it *bidi_it, int level, int end_flag)
1713{
1714 int dir = end_flag ? -bidi_it->scan_dir : bidi_it->scan_dir;
1715 int idx;
1716
1717 /* Try the cache first. */
1718 if ((idx = bidi_cache_find_level_change (level, dir, end_flag)) >= 0)
1719 bidi_cache_fetch_state (idx, bidi_it);
1720 else
1721 {
1722 int new_level;
1723
1724 if (end_flag)
1725 abort (); /* if we are at end of level, its edges must be cached */
1726
1727 bidi_cache_iterator_state (bidi_it, 1);
1728 do {
1729 new_level = bidi_level_of_next_char (bidi_it);
1730 bidi_cache_iterator_state (bidi_it, 1);
1731 } while (new_level >= level);
1732 }
1733}
1734
1735void
1736bidi_get_next_char_visually (struct bidi_it *bidi_it)
1737{
1738 int old_level, new_level, next_level;
1739 struct bidi_it prev_bidi_it;
1740
1741 if (bidi_it->scan_dir == 0)
1742 {
1743 bidi_it->scan_dir = 1; /* default to logical order */
1744 }
1745
1746 if (bidi_it->new_paragraph)
1747 bidi_paragraph_init (bidi_overriding_paragraph_direction, bidi_it);
1748 if (bidi_cache_idx == 0)
1749 bidi_copy_it (&prev_bidi_it, bidi_it);
1750
1751 old_level = bidi_it->resolved_level;
1752 new_level = bidi_level_of_next_char (bidi_it);
1753 if (bidi_it->ch == BIDI_EOB)
1754 return;
1755
1756 /* Reordering of resolved levels (clause L2) is implemented by
1757 jumping to the other edge of the level and flipping direction of
1758 scanning the buffer whenever we find a level change. */
1759 if (new_level != old_level)
1760 {
1761 int ascending = new_level > old_level;
1762 int level_to_search = ascending ? old_level + 1 : old_level;
1763 int incr = ascending ? 1 : -1;
1764 int expected_next_level = old_level + incr;
1765
1766 /* If we don't have anything cached yet, we need to cache the
1767 previous character we've seen, since we'll need it to record
1768 where to jump when the last non-base level is exhausted. */
1769 if (bidi_cache_idx == 0)
1770 bidi_cache_iterator_state (&prev_bidi_it, 1);
1771 /* Jump (or walk) to the other edge of this level. */
1772 bidi_find_other_level_edge (bidi_it, level_to_search, !ascending);
1773 /* Switch scan direction and peek at the next character in the
1774 new direction. */
1775 bidi_it->scan_dir = -bidi_it->scan_dir;
1776
1777 /* The following loop handles the case where the resolved level
1778 jumps by more than one. This is typical for numbers inside a
1779 run of text with left-to-right embedding direction, but can
1780 also happen in other situations. In those cases the decision
1781 where to continue after a level change, and in what direction,
1782 is tricky. For example, given a text like below:
1783
1784 abcdefgh
1785 11336622
1786
1787 (where the numbers below the text show the resolved levels),
1788 the result of reordering according to UAX#9 should be this:
1789
1790 efdcghba
1791
1792 This is implemented by the loop below which flips direction
1793 and jumps to the other edge of the level each time it finds
1794 the new level not to be the expected one. The expected level
1795 is always one more or one less than the previous one. */
1796 next_level = bidi_peek_at_next_level (bidi_it);
1797 while (next_level != expected_next_level)
1798 {
1799 expected_next_level += incr;
1800 level_to_search += incr;
1801 bidi_find_other_level_edge (bidi_it, level_to_search, !ascending);
1802 bidi_it->scan_dir = -bidi_it->scan_dir;
1803 next_level = bidi_peek_at_next_level (bidi_it);
1804 }
1805
1806 /* Finally, deliver the next character in the new direction. */
1807 next_level = bidi_level_of_next_char (bidi_it);
1808 }
1809
1810 if (bidi_it->scan_dir == 1 && bidi_cache_idx)
1811 {
1812 /* If we are at paragraph's base embedding level and beyond the
1813 last cached position, the cache's job is done and we can
1814 discard it. */
1815 if (bidi_it->resolved_level == bidi_it->level_stack[0].level
1816 && bidi_it->charpos > bidi_cache[bidi_cache_idx - 1].charpos)
1817 bidi_cache_reset ();
1818 /* But as long as we are caching during forward scan, we must
1819 cache each state, or else the cache integrity will be
1820 compromised: it assumes cached states correspond to buffer
1821 positions 1:1. */
1822 else
1823 bidi_cache_iterator_state (bidi_it, 1);
1824 }
1825}
1826
1827/* This is meant to be called from within the debugger, whenever you
1828 wish to examine the cache contents. */
1829void
1830bidi_dump_cached_states (void)
1831{
1832 int i;
1833 int ndigits = 1;
1834
1835 if (bidi_cache_idx == 0)
1836 {
1837 fprintf (stderr, "The cache is empty.\n");
1838 return;
1839 }
1840 fprintf (stderr, "Total of %d state%s in cache:\n",
1841 bidi_cache_idx, bidi_cache_idx == 1 ? "" : "s");
1842
1843 for (i = bidi_cache[bidi_cache_idx - 1].charpos; i > 0; i /= 10)
1844 ndigits++;
1845 fputs ("ch ", stderr);
1846 for (i = 0; i < bidi_cache_idx; i++)
1847 fprintf (stderr, "%*c", ndigits, bidi_cache[i].ch);
1848 fputs ("\n", stderr);
1849 fputs ("lvl ", stderr);
1850 for (i = 0; i < bidi_cache_idx; i++)
1851 fprintf (stderr, "%*d", ndigits, bidi_cache[i].resolved_level);
1852 fputs ("\n", stderr);
1853 fputs ("pos ", stderr);
1854 for (i = 0; i < bidi_cache_idx; i++)
1855 fprintf (stderr, "%*d", ndigits, bidi_cache[i].charpos);
1856 fputs ("\n", stderr);
1857}
1858
1859#ifdef TEST_STANDALONE
1860
1861#include <sys/stat.h>
1862#include <signal.h>
1863
1864static char display_line[80];
1865static int simulate_display;
1866static int incr = 1;
1867
1868void
1869signal_catcher (int sig)
1870{
1871 if (simulate_display)
1872 puts (display_line);
1873 else
1874 {
1875 puts ("<");
1876 fflush (stdout);
1877 }
1878 signal (sig, SIG_DFL);
1879 raise (sig);
1880}
1881
1882void
1883put_line (char *p)
1884{
1885 if (simulate_display)
1886 {
1887 if (incr == -1)
1888 {
1889 if (p >= display_line)
1890 memset (display_line, ' ', p - display_line + 1);
1891 }
1892 else
1893 *p = '\0';
1894 fputs (display_line, stdout);
1895 }
1896 fflush (stdout);
1897}
1898
1899char *
1900init_display_direction (bidi_dir_t default_dir, int base_level)
1901{
1902 char *p;
1903
1904 /* To which display margin should we flush the lines? */
1905 switch (default_dir)
1906 {
1907 case NEUTRAL_DIR:
1908 if ((base_level & 1) == 0)
1909 {
1910 p = display_line;
1911 incr = 1;
1912 }
1913 else
1914 {
1915 p = display_line + sizeof (display_line) - 1;
1916 *p-- = '\0';
1917 incr = -1;
1918 }
1919 break;
1920 case L2R:
1921 p = display_line;
1922 incr = 1;
1923 break;
1924 case R2L:
1925 p = display_line + sizeof (display_line) - 1;
1926 *p-- = '\0';
1927 incr = -1;
1928 break;
1929 default:
1930 abort ();
1931 }
1932
1933 return p;
1934}
1935
1936static char *
1937continuation_line (char *p, int need)
1938{
1939 if (incr == -1)
1940 {
1941 if (p < display_line + need)
1942 {
1943 *p-- = '/';
1944 put_line (p);
1945 putc ('\n', stdout);
1946 memset (display_line, '>', sizeof(display_line) - 1);
1947 p = display_line + sizeof (display_line) - 1;
1948 *p-- = '\0';
1949 }
1950 }
1951 else
1952 {
1953 if (p > display_line + sizeof(display_line) - need - 2)
1954 {
1955 *p++ = '\\';
1956 put_line (p);
1957 putc ('\n', stdout);
1958 memset (display_line, '<', sizeof(display_line) - 1);
1959 p = display_line;
1960 }
1961 }
1962
1963 return p;
1964}
1965
1966int main (int argc, char *argv[])
1967{
1968 bidi_dir_t default_dir = NEUTRAL_DIR;
1969 char lots_of_equals[] = "\n===============================================================================\n";
1970
1971
1972 if (argc > 1 && argv[1][0] == '-')
1973 {
1974 switch (argv[1][1])
1975 {
1976 case 'R':
1977 default_dir = R2L;
1978 simulate_display = 1;
1979 ++argv;
1980 break;
1981 case 'L':
1982 default_dir = L2R;
1983 simulate_display = 1;
1984 ++argv;
1985 break;
1986 case 'N':
1987 simulate_display = 1;
1988 ++argv;
1989 break;
1990 default:
1991 break;
1992 }
1993 bidi_overriding_paragraph_direction = default_dir;
1994 }
1995
1996 for (argv++; *argv; argv++)
1997 {
1998 FILE *in = fopen (*argv, "rb");
1999 struct stat stat_buf;
2000 struct bidi_it iterator;
2001 size_t i;
2002 char *p = display_line;
2003 int base_level;
2004 unsigned char *s, *d, *s_end;
2005
2006 if (!in || stat (*argv, &stat_buf))
2007 {
2008 perror (*argv);
2009 continue;
2010 }
2011
2012 if (stat_buf.st_size > input_buf_size)
2013 {
2014 input_buf = realloc (input_buf, stat_buf.st_size + 1);
2015 if (!input_buf)
2016 {
2017 perror ("realloc input buffer");
2018 continue;
2019 }
2020 input_buf_size = stat_buf.st_size;
2021 }
2022 if (fread (input_buf, 1, stat_buf.st_size, in) != stat_buf.st_size)
2023 {
2024 perror ("reading input");
2025 continue;
2026 }
2027 input_buf[stat_buf.st_size] = '\0';
2028 for (d = s = input_buf, s_end = s + stat_buf.st_size - 1; *s; s++)
2029 {
2030 if (*s != '\r' || s >= s_end || s[1] != '\n')
2031 *d++ = *s;
2032 }
2033 stat_buf.st_size = d - input_buf;
2034 input_buf[stat_buf.st_size] = '\0';
2035
2036 /* Done with administrivia, now for some real work... */
2037 signal (SIGABRT, signal_catcher);
2038 signal (SIGINT, signal_catcher);
2039 bidi_init_it (-1, default_dir, &iterator);
2040 if (simulate_display)
2041 {
2042 p = init_display_direction (default_dir,
2043 iterator.level_stack[0].level);
2044 }
2045
2046 memset (display_line, incr == -1 ? '>' : '<', sizeof (display_line) - 1);
2047 display_line[sizeof (display_line) - 1] = '\0';
2048 base_level = iterator.level_stack[0].level;
2049
2050 for (i = 0; i <= stat_buf.st_size; i++)
2051 {
2052 int c;
2053
2054 bidi_get_next_char_visually (&iterator);
2055 c = iterator.ch;
2056
2057 if (c == '\n' || c == BIDI_EOB)
2058 {
2059 if (simulate_display)
2060 {
2061 put_line (p);
2062 /* FIXME: if -R or -L, need to init paragraph here. */
2063 }
2064 if (c == BIDI_EOB)
2065 break;
2066 putc (c, stdout);
2067 }
2068 else if (c >= LRE_CHAR && c <= LRM_CHAR)
2069 {
2070 if (simulate_display)
2071 {
2072 p = continuation_line (p, 5);
2073 if (incr == -1)
2074 {
2075 memcpy (p - 4, bidi_name[c], 5);
2076 p -= 5;
2077 }
2078 else
2079 {
2080 memcpy (p, bidi_name[c], 5);
2081 p += 5;
2082 }
2083 }
2084 else
2085 fputs (bidi_name[c], stdout);
2086 }
2087 else if (c < ' ')
2088 {
2089 if (simulate_display)
2090 {
2091 p = continuation_line (p, 2);
2092 if (incr == -1)
2093 {
2094 *p-- = '@' + c;
2095 *p-- = '^';
2096 }
2097 else
2098 {
2099 *p++ = '^';
2100 *p++ = '@' + c;
2101 }
2102 }
2103 else
2104 printf ("^%c", (c | 0x40));
2105 }
2106 else
2107 {
2108 int c1 = (iterator.type == STRONG_R) ? bidi_mirror_char (c) : c;
2109
2110 if (simulate_display)
2111 {
2112 p = continuation_line (p, 1);
2113 *p = c1;
2114 p += incr;
2115 }
2116 else
2117 putc (c1, stdout);
2118 }
2119
2120 if (iterator.ch == '\n')
2121 {
2122 if (base_level != iterator.level_stack[0].level)
2123 base_level = iterator.level_stack[0].level;
2124 p = init_display_direction (default_dir, base_level);
2125 memset (display_line, incr == -1 ? '>' : '<',
2126 sizeof (display_line) - 1);
2127 }
2128 }
2129 fputs (lots_of_equals, stdout);
2130 fclose (in);
2131 }
2132 return 0;
2133}
2134#endif
diff --git a/src/buffer.c b/src/buffer.c
index 8657fd8cdff..35e1f4d22ec 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -5186,7 +5186,8 @@ init_buffer_once ()
5186 buffer_defaults.truncate_lines = Qnil; 5186 buffer_defaults.truncate_lines = Qnil;
5187 buffer_defaults.word_wrap = Qnil; 5187 buffer_defaults.word_wrap = Qnil;
5188 buffer_defaults.ctl_arrow = Qt; 5188 buffer_defaults.ctl_arrow = Qt;
5189 buffer_defaults.direction_reversed = Qnil; 5189 buffer_defaults.enable_bidi_display = Qnil;
5190 buffer_defaults.orientation_reversed = Qnil;
5190 buffer_defaults.cursor_type = Qt; 5191 buffer_defaults.cursor_type = Qt;
5191 buffer_defaults.extra_line_spacing = Qnil; 5192 buffer_defaults.extra_line_spacing = Qnil;
5192 buffer_defaults.cursor_in_non_selected_windows = Qt; 5193 buffer_defaults.cursor_in_non_selected_windows = Qt;
@@ -5271,7 +5272,8 @@ init_buffer_once ()
5271 XSETFASTINT (buffer_local_flags.syntax_table, idx); ++idx; 5272 XSETFASTINT (buffer_local_flags.syntax_table, idx); ++idx;
5272 XSETFASTINT (buffer_local_flags.cache_long_line_scans, idx); ++idx; 5273 XSETFASTINT (buffer_local_flags.cache_long_line_scans, idx); ++idx;
5273 XSETFASTINT (buffer_local_flags.category_table, idx); ++idx; 5274 XSETFASTINT (buffer_local_flags.category_table, idx); ++idx;
5274 XSETFASTINT (buffer_local_flags.direction_reversed, idx); ++idx; 5275 XSETFASTINT (buffer_local_flags.enable_bidi_display, idx); ++idx;
5276 XSETFASTINT (buffer_local_flags.orientation_reversed, idx); ++idx;
5275 XSETFASTINT (buffer_local_flags.buffer_file_coding_system, idx); 5277 XSETFASTINT (buffer_local_flags.buffer_file_coding_system, idx);
5276 /* Make this one a permanent local. */ 5278 /* Make this one a permanent local. */
5277 buffer_permanent_local_flags[idx++] = 1; 5279 buffer_permanent_local_flags[idx++] = 1;
@@ -5528,10 +5530,15 @@ This is the same as (default-value 'abbrev-mode). */);
5528 doc: /* Default value of `ctl-arrow' for buffers that do not override it. 5530 doc: /* Default value of `ctl-arrow' for buffers that do not override it.
5529This is the same as (default-value 'ctl-arrow). */); 5531This is the same as (default-value 'ctl-arrow). */);
5530 5532
5531 DEFVAR_LISP_NOPRO ("default-direction-reversed", 5533 DEFVAR_LISP_NOPRO ("default-enable-bidi-display",
5532 &buffer_defaults.direction_reversed, 5534 &buffer_defaults.enable_bidi_display,
5533 doc: /* Default value of `direction-reversed' for buffers that do not override it. 5535 doc: /* *Default value of `enable-bidi-display' for buffers not overriding it.
5534This is the same as (default-value 'direction-reversed). */); 5536This is the same as (default-value 'enable-bidi-display). */);
5537
5538 DEFVAR_LISP_NOPRO ("default-orientation-reversed",
5539 &buffer_defaults.orientation_reversed,
5540 doc: /* *Default value of `orientation-reversed' for buffers that do not override it.
5541This is the same as (default-value 'orientation-reversed). */);
5535 5542
5536 DEFVAR_LISP_NOPRO ("default-enable-multibyte-characters", 5543 DEFVAR_LISP_NOPRO ("default-enable-multibyte-characters",
5537 &buffer_defaults.enable_multibyte_characters, 5544 &buffer_defaults.enable_multibyte_characters,
@@ -5789,11 +5796,17 @@ The variable `coding-system-for-write', if non-nil, overrides this variable.
5789 5796
5790This variable is never applied to a way of decoding a file while reading it. */); 5797This variable is never applied to a way of decoding a file while reading it. */);
5791 5798
5792 DEFVAR_PER_BUFFER ("direction-reversed", &current_buffer->direction_reversed, 5799 DEFVAR_PER_BUFFER ("orientation-reversed",
5793 Qnil, 5800 &current_buffer->orientation_reversed, Qnil,
5794 doc: /* *Non-nil means lines in the buffer are displayed right to left. */); 5801 doc: /* Non-nil means set beginning of lines at the right end of the window.
5802See also the variable `enable-bidi-display'. */);
5803
5804 DEFVAR_PER_BUFFER ("enable-bidi-display",
5805 &current_buffer->enable_bidi_display, Qnil,
5806 doc: /*Non-nil means display bidi text in correct visual order.
5807See also the variable `orientation-reversed'. */);
5795 5808
5796 DEFVAR_PER_BUFFER ("truncate-lines", &current_buffer->truncate_lines, Qnil, 5809 DEFVAR_PER_BUFFER ("truncate-lines", &current_buffer->truncate_lines, Qnil,
5797 doc: /* *Non-nil means do not display continuation lines. 5810 doc: /* *Non-nil means do not display continuation lines.
5798Instead, give each line of text just one screen line. 5811Instead, give each line of text just one screen line.
5799 5812
diff --git a/src/buffer.h b/src/buffer.h
index 9f57a292053..8197ac6328c 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -658,8 +658,10 @@ struct buffer
658 Lisp_Object word_wrap; 658 Lisp_Object word_wrap;
659 /* Non-nil means display ctl chars with uparrow. */ 659 /* Non-nil means display ctl chars with uparrow. */
660 Lisp_Object ctl_arrow; 660 Lisp_Object ctl_arrow;
661 /* Non-nil means display text from right to left. */ 661 /* Non-nil means display bidi text in correct visual order. */
662 Lisp_Object direction_reversed; 662 Lisp_Object enable_bidi_display;
663 /* Non-nil means set beginning of lines at the right end of windows. */
664 Lisp_Object orientation_reversed;
663 /* Non-nil means do selective display; 665 /* Non-nil means do selective display;
664 see doc string in syms_of_buffer (buffer.c) for details. */ 666 see doc string in syms_of_buffer (buffer.c) for details. */
665 Lisp_Object selective_display; 667 Lisp_Object selective_display;
diff --git a/src/dispextern.h b/src/dispextern.h
index f28cae6d8b3..0b3310c8f69 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -1702,6 +1702,79 @@ struct face_cache
1702 1702
1703extern int face_change_count; 1703extern int face_change_count;
1704 1704
1705/* For BIDI */
1706#define BIDI_MAXLEVEL 64
1707
1708/* Data type for describing the bidirectional character types. */
1709typedef enum {
1710 UNKNOWN_BT,
1711 STRONG_L, /* strong left-to-right */
1712 STRONG_R, /* strong right-to-left */
1713 STRONG_AL, /* arabic right-to-left letter */
1714 LRE, /* left-to-right embedding */
1715 LRO, /* left-to-right override */
1716 RLE, /* right-to-left embedding */
1717 RLO, /* right-to-left override */
1718 PDF, /* pop directional format */
1719 WEAK_EN, /* european number */
1720 WEAK_ES, /* european number separator */
1721 WEAK_ET, /* european number terminator */
1722 WEAK_AN, /* arabic number */
1723 WEAK_CS, /* common separator */
1724 WEAK_NSM, /* non-spacing mark */
1725 WEAK_BN, /* boundary neutral */
1726 NEUTRAL_B, /* paragraph separator */
1727 NEUTRAL_S, /* segment separator */
1728 NEUTRAL_WS, /* whitespace */
1729 NEUTRAL_ON /* other neutrals */
1730} bidi_type_t;
1731
1732/* The basic directionality data type. */
1733typedef enum { NEUTRAL_DIR, L2R, R2L } bidi_dir_t;
1734
1735/* Data type for storing information about characters we need to
1736 remember. */
1737struct bidi_saved_info {
1738 int bytepos, charpos; /* character's buffer position */
1739 bidi_type_t type; /* character bidi type */
1740 bidi_type_t orig_type; /* original type of the character, after W1 */
1741 bidi_type_t pristine_type; /* type as we found it in the buffer */
1742};
1743
1744/* Data type for keeping track of saved embedding levels and override
1745 status information. */
1746struct bidi_stack {
1747 int level;
1748 bidi_dir_t override;
1749};
1750
1751/* Data type for iterating over bidi text. */
1752struct bidi_it {
1753 int bytepos; /* iterator's position in buffer */
1754 int charpos;
1755 int ch; /* the character itself */
1756 int ch_len; /* the length of its multibyte sequence */
1757 bidi_type_t type; /* type of this character */
1758 bidi_type_t orig_type; /* original type, after overrides and W1 */
1759 bidi_type_t pristine_type; /* original type, as found in the buffer */
1760 int resolved_level; /* final resolved level of this character */
1761 int invalid_levels; /* how many PDFs should we ignore */
1762 int invalid_rl_levels; /* how many PDFs from RLE/RLO should ignore */
1763 int new_paragraph; /* if non-zero, a new paragraph begins here */
1764 int prev_was_pdf; /* if non-zero, prev char was PDF */
1765 struct bidi_saved_info prev; /* info about the previous character */
1766 struct bidi_saved_info last_strong; /* last-seen strong directional char */
1767 struct bidi_saved_info next_for_neutral; /* surrounding characters for... */
1768 struct bidi_saved_info prev_for_neutral; /* ...resolving neutrals */
1769 struct bidi_saved_info next_for_ws; /* character after sequence of ws */
1770 int next_en_pos; /* position of next EN char for ET */
1771 int ignore_bn_limit; /* position until which we should ignore BNs */
1772 bidi_dir_t sor; /* direction of start-of-run in effect */
1773 int scan_dir; /* direction of text scan */
1774 int stack_idx; /* index of current data on the stack */
1775 struct bidi_stack level_stack[BIDI_MAXLEVEL]; /* stack of embedding levels */
1776};
1777
1705 1778
1706 1779
1707 1780
@@ -2233,6 +2306,12 @@ struct it
2233 2306
2234 /* Face of the right fringe glyph. */ 2307 /* Face of the right fringe glyph. */
2235 unsigned right_user_fringe_face_id : FACE_ID_BITS; 2308 unsigned right_user_fringe_face_id : FACE_ID_BITS;
2309
2310 /* 1 means we need bidi processing. */
2311 int bidi_p;
2312
2313 /* For iterating over bidi text. */
2314 struct bidi_it bidi_it;
2236}; 2315};
2237 2316
2238 2317
@@ -2704,6 +2783,12 @@ extern EMACS_INT tool_bar_button_relief;
2704 Function Prototypes 2783 Function Prototypes
2705 ***********************************************************************/ 2784 ***********************************************************************/
2706 2785
2786/* Defined in bidi.c */
2787
2788extern void bidi_init_it P_ ((int pos, bidi_dir_t dir,
2789 struct bidi_it *bidi_it));
2790extern void bidi_get_next_char_visually P_ ((struct bidi_it *bidi_it));
2791
2707/* Defined in xdisp.c */ 2792/* Defined in xdisp.c */
2708 2793
2709struct glyph_row *row_containing_pos P_ ((struct window *, int, 2794struct glyph_row *row_containing_pos P_ ((struct window *, int,
diff --git a/src/dispnew.c b/src/dispnew.c
index 0039ec0d181..a6984d96a15 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -3776,8 +3776,12 @@ direct_output_forward_char (n)
3776 if (!display_completed || cursor_in_echo_area) 3776 if (!display_completed || cursor_in_echo_area)
3777 return 0; 3777 return 0;
3778 3778
3779 /* Give up if the buffer's direction is reversed. */ 3779 /* Give up if we need bidi display. */
3780 if (!NILP (XBUFFER (w->buffer)->direction_reversed)) 3780 if (!NILP (XBUFFER (w->buffer)->enable_bidi_display))
3781 return 0;
3782
3783 /* Give up if the buffer's orientation is reversed. */
3784 if (!NILP (XBUFFER (w->buffer)->orientation_reversed))
3781 return 0; 3785 return 0;
3782 3786
3783 /* Can't use direct output if highlighting a region. */ 3787 /* Can't use direct output if highlighting a region. */
diff --git a/src/xdisp.c b/src/xdisp.c
index 435f5dc5334..560ca38e2d0 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -2658,6 +2658,9 @@ init_iterator (it, w, charpos, bytepos, row, base_face_id)
2658 /* Are multibyte characters enabled in current_buffer? */ 2658 /* Are multibyte characters enabled in current_buffer? */
2659 it->multibyte_p = !NILP (current_buffer->enable_multibyte_characters); 2659 it->multibyte_p = !NILP (current_buffer->enable_multibyte_characters);
2660 2660
2661 /* Do we need multibyte processing? */
2662 it->bidi_p = !NILP (current_buffer->enable_bidi_display);
2663
2661 /* Non-zero if we should highlight the region. */ 2664 /* Non-zero if we should highlight the region. */
2662 highlight_region_p 2665 highlight_region_p
2663 = (!NILP (Vtransient_mark_mode) 2666 = (!NILP (Vtransient_mark_mode)
@@ -5515,6 +5518,16 @@ reseat_1 (it, pos, set_stop_p)
5515 it->string_from_display_prop_p = 0; 5518 it->string_from_display_prop_p = 0;
5516 it->face_before_selective_p = 0; 5519 it->face_before_selective_p = 0;
5517 5520
5521 if (it->bidi_p)
5522 {
5523 bidi_init_it (pos.charpos - 1, L2R, &it->bidi_it);
5524 bidi_get_next_char_visually (&it->bidi_it);
5525
5526 pos.charpos = it->bidi_it.charpos;
5527 pos.bytepos = it->bidi_it.bytepos;
5528 it->current.pos = it->position = pos;
5529 }
5530
5518 if (set_stop_p) 5531 if (set_stop_p)
5519 it->stop_charpos = CHARPOS (pos); 5532 it->stop_charpos = CHARPOS (pos);
5520} 5533}
@@ -6078,8 +6091,18 @@ set_iterator_to_next (it, reseat_p)
6078 else 6091 else
6079 { 6092 {
6080 xassert (it->len != 0); 6093 xassert (it->len != 0);
6081 IT_BYTEPOS (*it) += it->len; 6094
6082 IT_CHARPOS (*it) += 1; 6095 if (! it->bidi_p)
6096 {
6097 IT_BYTEPOS (*it) += it->len;
6098 IT_CHARPOS (*it) += 1;
6099 }
6100 else
6101 {
6102 bidi_get_next_char_visually (&it->bidi_it);
6103 IT_BYTEPOS (*it) = it->bidi_it.charpos;
6104 IT_CHARPOS (*it) = it->bidi_it.bytepos;
6105 }
6083 xassert (IT_BYTEPOS (*it) == CHAR_TO_BYTE (IT_CHARPOS (*it))); 6106 xassert (IT_BYTEPOS (*it) == CHAR_TO_BYTE (IT_CHARPOS (*it)));
6084 } 6107 }
6085 break; 6108 break;
generated by cgit v1.2.1 (git 2.18.0) at 2026-01-17 21:23:59 +0000