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a50699fd JA |
1 | /* Code for doing intervals. |
2 | Copyright (C) 1991, 1992 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GNU Emacs. | |
5 | ||
6 | GNU Emacs is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 1, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU Emacs is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU Emacs; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | ||
21 | /* NOTES: | |
22 | ||
23 | Have to ensure that we can't put symbol nil on a plist, or some | |
24 | functions may work incorrectly. | |
25 | ||
26 | An idea: Have the owner of the tree keep count of splits and/or | |
27 | insertion lengths (in intervals), and balance after every N. | |
28 | ||
29 | Need to call *_left_hook when buffer is killed. | |
30 | ||
31 | Scan for zero-length, or 0-length to see notes about handling | |
32 | zero length interval-markers. | |
33 | ||
34 | There are comments around about freeing intervals. It might be | |
35 | faster to explicitly free them (put them on the free list) than | |
36 | to GC them. | |
37 | ||
38 | */ | |
39 | ||
40 | ||
41 | #include "config.h" | |
42 | #include "lisp.h" | |
43 | #include "intervals.h" | |
44 | #include "buffer.h" | |
45 | #include "screen.h" | |
46 | ||
47 | /* Factor for weight-balancing interval trees. */ | |
48 | Lisp_Object interval_balance_threshold; | |
49 | \f | |
50 | /* Utility functions for intervals. */ | |
51 | ||
52 | ||
53 | /* Create the root interval of some object, a buffer or string. */ | |
54 | ||
55 | INTERVAL | |
56 | create_root_interval (parent) | |
57 | Lisp_Object parent; | |
58 | { | |
59 | INTERVAL new = make_interval (); | |
60 | ||
61 | if (XTYPE (parent) == Lisp_Buffer) | |
62 | { | |
63 | new->total_length = BUF_Z (XBUFFER (parent)) - 1; | |
64 | XBUFFER (parent)->intervals = new; | |
65 | } | |
66 | else if (XTYPE (parent) == Lisp_String) | |
67 | { | |
68 | new->total_length = XSTRING (parent)->size; | |
69 | XSTRING (parent)->intervals = new; | |
70 | } | |
71 | ||
72 | new->parent = (INTERVAL) parent; | |
73 | new->position = 1; | |
74 | ||
75 | return new; | |
76 | } | |
77 | ||
78 | /* Make the interval TARGET have exactly the properties of SOURCE */ | |
79 | ||
80 | void | |
81 | copy_properties (source, target) | |
82 | register INTERVAL source, target; | |
83 | { | |
84 | if (DEFAULT_INTERVAL_P (source) && DEFAULT_INTERVAL_P (target)) | |
85 | return; | |
86 | ||
87 | COPY_INTERVAL_CACHE (source, target); | |
88 | target->plist = Fcopy_sequence (source->plist); | |
89 | } | |
90 | ||
91 | /* Merge the properties of interval SOURCE into the properties | |
92 | of interval TARGET. */ | |
93 | ||
94 | static void | |
95 | merge_properties (source, target) | |
96 | register INTERVAL source, target; | |
97 | { | |
98 | register Lisp_Object o, sym, val; | |
99 | ||
100 | if (DEFAULT_INTERVAL_P (source) && DEFAULT_INTERVAL_P (target)) | |
101 | return; | |
102 | ||
103 | MERGE_INTERVAL_CACHE (source, target); | |
104 | ||
105 | o = source->plist; | |
106 | while (! EQ (o, Qnil)) | |
107 | { | |
108 | sym = Fcar (o); | |
109 | val = Fmemq (sym, target->plist); | |
110 | ||
111 | if (NILP (val)) | |
112 | { | |
113 | o = Fcdr (o); | |
114 | val = Fcar (o); | |
115 | target->plist = Fcons (sym, Fcons (val, target->plist)); | |
116 | o = Fcdr (o); | |
117 | } | |
118 | else | |
119 | o = Fcdr (Fcdr (o)); | |
120 | } | |
121 | } | |
122 | ||
123 | /* Return 1 if the two intervals have the same properties, | |
124 | 0 otherwise. */ | |
125 | ||
126 | int | |
127 | intervals_equal (i0, i1) | |
128 | INTERVAL i0, i1; | |
129 | { | |
130 | register Lisp_Object i0_cdr, i0_sym, i1_val; | |
131 | register i1_len; | |
132 | ||
133 | if (DEFAULT_INTERVAL_P (i0) && DEFAULT_INTERVAL_P (i1)) | |
134 | return 1; | |
135 | ||
136 | i1_len = XFASTINT (Flength (i1->plist)); | |
137 | if (i1_len & 0x1) /* Paranoia -- plists are always even */ | |
138 | abort (); | |
139 | i1_len /= 2; | |
140 | i0_cdr = i0->plist; | |
141 | while (!NILP (i0_cdr)) | |
142 | { | |
143 | /* Lengths of the two plists were unequal */ | |
144 | if (i1_len == 0) | |
145 | return 0; | |
146 | ||
147 | i0_sym = Fcar (i0_cdr); | |
148 | i1_val = Fmemq (i0_sym, i1->plist); | |
149 | ||
150 | /* i0 has something i1 doesn't */ | |
151 | if (EQ (i1_val, Qnil)) | |
152 | return 0; | |
153 | ||
154 | /* i0 and i1 both have sym, but it has different values in each */ | |
155 | i0_cdr = Fcdr (i0_cdr); | |
156 | if (! Fequal (i1_val, Fcar (i0_cdr))) | |
157 | return 0; | |
158 | ||
159 | i0_cdr = Fcdr (i0_cdr); | |
160 | i1_len--; | |
161 | } | |
162 | ||
163 | /* Lengths of the two plists were unequal */ | |
164 | if (i1_len > 0) | |
165 | return 0; | |
166 | ||
167 | return 1; | |
168 | } | |
169 | \f | |
170 | static int icount; | |
171 | static int idepth; | |
172 | static int zero_length; | |
173 | ||
174 | static int depth; | |
175 | ||
176 | /* Traverse an interval tree TREE, performing FUNCTION on each node. | |
177 | ||
178 | Perhaps we should pass the depth as an argument. */ | |
179 | ||
180 | void | |
181 | traverse_intervals (tree, position, function) | |
182 | INTERVAL tree; | |
183 | int position; | |
184 | void (* function) (); | |
185 | { | |
186 | if (NULL_INTERVAL_P (tree)) | |
187 | return; | |
188 | ||
189 | depth++; | |
190 | traverse_intervals (tree->left, position, function); | |
191 | position += LEFT_TOTAL_LENGTH (tree); | |
192 | tree->position = position; | |
193 | (*function) (tree); | |
194 | position += LENGTH (tree); | |
195 | traverse_intervals (tree->right, position, function); | |
196 | depth--; | |
197 | } | |
198 | \f | |
199 | #if 0 | |
200 | /* These functions are temporary, for debugging purposes only. */ | |
201 | ||
202 | INTERVAL search_interval, found_interval; | |
203 | ||
204 | void | |
205 | check_for_interval (i) | |
206 | register INTERVAL i; | |
207 | { | |
208 | if (i == search_interval) | |
209 | { | |
210 | found_interval = i; | |
211 | icount++; | |
212 | } | |
213 | } | |
214 | ||
215 | INTERVAL | |
216 | search_for_interval (i, tree) | |
217 | register INTERVAL i, tree; | |
218 | { | |
219 | icount = 0; | |
220 | search_interval = i; | |
221 | found_interval = NULL_INTERVAL; | |
222 | traverse_intervals (tree, 1, &check_for_interval); | |
223 | return found_interval; | |
224 | } | |
225 | ||
226 | static void | |
227 | inc_interval_count (i) | |
228 | INTERVAL i; | |
229 | { | |
230 | icount++; | |
231 | if (LENGTH (i) == 0) | |
232 | zero_length++; | |
233 | if (depth > idepth) | |
234 | idepth = depth; | |
235 | } | |
236 | ||
237 | int | |
238 | count_intervals (i) | |
239 | register INTERVAL i; | |
240 | { | |
241 | icount = 0; | |
242 | idepth = 0; | |
243 | zero_length = 0; | |
244 | traverse_intervals (i, 1, &inc_interval_count); | |
245 | ||
246 | return icount; | |
247 | } | |
248 | ||
249 | static INTERVAL | |
250 | root_interval (interval) | |
251 | INTERVAL interval; | |
252 | { | |
253 | register INTERVAL i = interval; | |
254 | ||
255 | while (! ROOT_INTERVAL_P (i)) | |
256 | i = i->parent; | |
257 | ||
258 | return i; | |
259 | } | |
260 | #endif | |
261 | \f | |
262 | /* Assuming that a left child exists, perform the following operation: | |
263 | ||
264 | A B | |
265 | / \ / \ | |
266 | B => A | |
267 | / \ / \ | |
268 | c c | |
269 | */ | |
270 | ||
271 | static INTERVAL | |
272 | rotate_right (interval) | |
273 | INTERVAL interval; | |
274 | { | |
275 | INTERVAL i; | |
276 | INTERVAL B = interval->left; | |
277 | int len = LENGTH (interval); | |
278 | ||
279 | /* Deal with any Parent of A; make it point to B. */ | |
280 | if (! ROOT_INTERVAL_P (interval)) | |
281 | if (AM_LEFT_CHILD (interval)) | |
282 | interval->parent->left = interval->left; | |
283 | else | |
284 | interval->parent->right = interval->left; | |
285 | interval->left->parent = interval->parent; | |
286 | ||
287 | /* B gets the same length as A, since it get A's position in the tree. */ | |
288 | interval->left->total_length = interval->total_length; | |
289 | ||
290 | /* B becomes the parent of A. */ | |
291 | i = interval->left->right; | |
292 | interval->left->right = interval; | |
293 | interval->parent = interval->left; | |
294 | ||
295 | /* A gets c as left child. */ | |
296 | interval->left = i; | |
297 | if (! NULL_INTERVAL_P (i)) | |
298 | i->parent = interval; | |
299 | interval->total_length = (len + LEFT_TOTAL_LENGTH (interval) | |
300 | + RIGHT_TOTAL_LENGTH (interval)); | |
301 | ||
302 | return B; | |
303 | } | |
304 | \f | |
305 | /* Assuming that a right child exists, perform the following operation: | |
306 | ||
307 | A B | |
308 | / \ / \ | |
309 | B => A | |
310 | / \ / \ | |
311 | c c | |
312 | */ | |
313 | ||
314 | static INTERVAL | |
315 | rotate_left (interval) | |
316 | INTERVAL interval; | |
317 | { | |
318 | INTERVAL i; | |
319 | INTERVAL B = interval->right; | |
320 | int len = LENGTH (interval); | |
321 | ||
322 | /* Deal with the parent of A. */ | |
323 | if (! ROOT_INTERVAL_P (interval)) | |
324 | if (AM_LEFT_CHILD (interval)) | |
325 | interval->parent->left = interval->right; | |
326 | else | |
327 | interval->parent->right = interval->right; | |
328 | interval->right->parent = interval->parent; | |
329 | ||
330 | /* B must have the same total length of A. */ | |
331 | interval->right->total_length = interval->total_length; | |
332 | ||
333 | /* Make B the parent of A */ | |
334 | i = interval->right->left; | |
335 | interval->right->left = interval; | |
336 | interval->parent = interval->right; | |
337 | ||
338 | /* Make A point to c */ | |
339 | interval->right = i; | |
340 | if (! NULL_INTERVAL_P (i)) | |
341 | i->parent = interval; | |
342 | interval->total_length = (len + LEFT_TOTAL_LENGTH (interval) | |
343 | + RIGHT_TOTAL_LENGTH (interval)); | |
344 | ||
345 | return B; | |
346 | } | |
347 | \f | |
90ba40fc JA |
348 | /* Split INTERVAL into two pieces, starting the second piece at character |
349 | position OFFSET (counting from 1), relative to INTERVAL. The right-hand | |
350 | piece (second, lexicographically) is returned. | |
351 | ||
352 | The size and position fields of the two intervals are set based upon | |
353 | those of the original interval. The property list of the new interval | |
354 | is reset, thus it is up to the caller to do the right thing with the | |
355 | result. | |
a50699fd JA |
356 | |
357 | Note that this does not change the position of INTERVAL; if it is a root, | |
358 | it is still a root after this operation. */ | |
359 | ||
360 | INTERVAL | |
90ba40fc | 361 | split_interval_right (interval, offset) |
a50699fd | 362 | INTERVAL interval; |
90ba40fc | 363 | int offset; |
a50699fd JA |
364 | { |
365 | INTERVAL new = make_interval (); | |
366 | int position = interval->position; | |
90ba40fc | 367 | int new_length = LENGTH (interval) - offset + 1; |
a50699fd | 368 | |
90ba40fc | 369 | new->position = position + offset - 1; |
a50699fd | 370 | new->parent = interval; |
a50699fd JA |
371 | |
372 | if (LEAF_INTERVAL_P (interval) || NULL_RIGHT_CHILD (interval)) | |
373 | { | |
374 | interval->right = new; | |
375 | new->total_length = new_length; | |
376 | ||
377 | return new; | |
378 | } | |
379 | ||
380 | /* Insert the new node between INTERVAL and its right child. */ | |
381 | new->right = interval->right; | |
382 | interval->right->parent = new; | |
383 | interval->right = new; | |
384 | ||
385 | new->total_length = new_length + new->right->total_length; | |
386 | ||
387 | return new; | |
388 | } | |
389 | ||
90ba40fc JA |
390 | /* Split INTERVAL into two pieces, starting the second piece at character |
391 | position OFFSET (counting from 1), relative to INTERVAL. The left-hand | |
392 | piece (first, lexicographically) is returned. | |
a50699fd | 393 | |
90ba40fc JA |
394 | The size and position fields of the two intervals are set based upon |
395 | those of the original interval. The property list of the new interval | |
396 | is reset, thus it is up to the caller to do the right thing with the | |
397 | result. | |
398 | ||
399 | Note that this does not change the position of INTERVAL; if it is a root, | |
400 | it is still a root after this operation. */ | |
a50699fd JA |
401 | |
402 | INTERVAL | |
90ba40fc | 403 | split_interval_left (interval, offset) |
a50699fd | 404 | INTERVAL interval; |
90ba40fc | 405 | int offset; |
a50699fd JA |
406 | { |
407 | INTERVAL new = make_interval (); | |
408 | int position = interval->position; | |
90ba40fc | 409 | int new_length = offset - 1; |
a50699fd | 410 | |
a50699fd | 411 | new->position = interval->position; |
90ba40fc | 412 | interval->position = interval->position + offset - 1; |
a50699fd JA |
413 | new->parent = interval; |
414 | ||
415 | if (NULL_LEFT_CHILD (interval)) | |
416 | { | |
417 | interval->left = new; | |
418 | new->total_length = new_length; | |
419 | ||
420 | return new; | |
421 | } | |
422 | ||
423 | /* Insert the new node between INTERVAL and its left child. */ | |
424 | new->left = interval->left; | |
425 | new->left->parent = new; | |
426 | interval->left = new; | |
427 | new->total_length = LENGTH (new) + LEFT_TOTAL_LENGTH (new); | |
428 | ||
429 | return new; | |
430 | } | |
431 | \f | |
90ba40fc JA |
432 | /* Find the interval containing text position POSITION in the text |
433 | represented by the interval tree TREE. POSITION is relative to | |
434 | the beginning of that text. | |
a50699fd | 435 | |
90ba40fc JA |
436 | The `position' field, which is a cache of an interval's position, |
437 | is updated in the interval found. Other functions (e.g., next_interval) | |
438 | will update this cache based on the result of find_interval. */ | |
439 | ||
440 | INLINE INTERVAL | |
a50699fd JA |
441 | find_interval (tree, position) |
442 | register INTERVAL tree; | |
443 | register int position; | |
444 | { | |
445 | register int relative_position = position; | |
446 | ||
447 | if (NULL_INTERVAL_P (tree)) | |
448 | return NULL_INTERVAL; | |
449 | ||
450 | if (position > TOTAL_LENGTH (tree)) | |
451 | abort (); /* Paranoia */ | |
452 | #if 0 | |
453 | position = TOTAL_LENGTH (tree); | |
454 | #endif | |
455 | ||
456 | while (1) | |
457 | { | |
458 | if (relative_position <= LEFT_TOTAL_LENGTH (tree)) | |
459 | { | |
460 | tree = tree->left; | |
461 | } | |
462 | else if (relative_position > (TOTAL_LENGTH (tree) | |
463 | - RIGHT_TOTAL_LENGTH (tree))) | |
464 | { | |
465 | relative_position -= (TOTAL_LENGTH (tree) | |
466 | - RIGHT_TOTAL_LENGTH (tree)); | |
467 | tree = tree->right; | |
468 | } | |
469 | else | |
470 | { | |
471 | tree->position = LEFT_TOTAL_LENGTH (tree) | |
472 | + position - relative_position + 1; | |
473 | return tree; | |
474 | } | |
475 | } | |
476 | } | |
477 | \f | |
478 | /* Find the succeeding interval (lexicographically) to INTERVAL. | |
90ba40fc JA |
479 | Sets the `position' field based on that of INTERVAL (see |
480 | find_interval). */ | |
a50699fd JA |
481 | |
482 | INTERVAL | |
483 | next_interval (interval) | |
484 | register INTERVAL interval; | |
485 | { | |
486 | register INTERVAL i = interval; | |
487 | register int next_position; | |
488 | ||
489 | if (NULL_INTERVAL_P (i)) | |
490 | return NULL_INTERVAL; | |
491 | next_position = interval->position + LENGTH (interval); | |
492 | ||
493 | if (! NULL_RIGHT_CHILD (i)) | |
494 | { | |
495 | i = i->right; | |
496 | while (! NULL_LEFT_CHILD (i)) | |
497 | i = i->left; | |
498 | ||
499 | i->position = next_position; | |
500 | return i; | |
501 | } | |
502 | ||
503 | while (! NULL_PARENT (i)) | |
504 | { | |
505 | if (AM_LEFT_CHILD (i)) | |
506 | { | |
507 | i = i->parent; | |
508 | i->position = next_position; | |
509 | return i; | |
510 | } | |
511 | ||
512 | i = i->parent; | |
513 | } | |
514 | ||
515 | return NULL_INTERVAL; | |
516 | } | |
517 | ||
518 | /* Find the preceding interval (lexicographically) to INTERVAL. | |
90ba40fc JA |
519 | Sets the `position' field based on that of INTERVAL (see |
520 | find_interval). */ | |
a50699fd JA |
521 | |
522 | INTERVAL | |
523 | previous_interval (interval) | |
524 | register INTERVAL interval; | |
525 | { | |
526 | register INTERVAL i; | |
527 | register position_of_previous; | |
528 | ||
529 | if (NULL_INTERVAL_P (interval)) | |
530 | return NULL_INTERVAL; | |
531 | ||
532 | if (! NULL_LEFT_CHILD (interval)) | |
533 | { | |
534 | i = interval->left; | |
535 | while (! NULL_RIGHT_CHILD (i)) | |
536 | i = i->right; | |
537 | ||
538 | i->position = interval->position - LENGTH (i); | |
539 | return i; | |
540 | } | |
541 | ||
542 | i = interval; | |
543 | while (! NULL_PARENT (i)) | |
544 | { | |
545 | if (AM_RIGHT_CHILD (i)) | |
546 | { | |
547 | i = i->parent; | |
548 | ||
549 | i->position = interval->position - LENGTH (i); | |
550 | return i; | |
551 | } | |
552 | i = i->parent; | |
553 | } | |
554 | ||
555 | return NULL_INTERVAL; | |
556 | } | |
557 | \f | |
90ba40fc | 558 | #if 0 |
a50699fd JA |
559 | /* Traverse a path down the interval tree TREE to the interval |
560 | containing POSITION, adjusting all nodes on the path for | |
561 | an addition of LENGTH characters. Insertion between two intervals | |
562 | (i.e., point == i->position, where i is second interval) means | |
563 | text goes into second interval. | |
564 | ||
565 | Modifications are needed to handle the hungry bits -- after simply | |
566 | finding the interval at position (don't add length going down), | |
567 | if it's the beginning of the interval, get the previous interval | |
568 | and check the hugry bits of both. Then add the length going back up | |
569 | to the root. */ | |
570 | ||
571 | static INTERVAL | |
572 | adjust_intervals_for_insertion (tree, position, length) | |
573 | INTERVAL tree; | |
574 | int position, length; | |
575 | { | |
576 | register int relative_position; | |
577 | register INTERVAL this; | |
578 | ||
579 | if (TOTAL_LENGTH (tree) == 0) /* Paranoia */ | |
580 | abort (); | |
581 | ||
582 | /* If inserting at point-max of a buffer, that position | |
583 | will be out of range */ | |
584 | if (position > TOTAL_LENGTH (tree)) | |
585 | position = TOTAL_LENGTH (tree); | |
586 | relative_position = position; | |
587 | this = tree; | |
588 | ||
589 | while (1) | |
590 | { | |
591 | if (relative_position <= LEFT_TOTAL_LENGTH (this)) | |
592 | { | |
593 | this->total_length += length; | |
594 | this = this->left; | |
595 | } | |
596 | else if (relative_position > (TOTAL_LENGTH (this) | |
597 | - RIGHT_TOTAL_LENGTH (this))) | |
598 | { | |
599 | relative_position -= (TOTAL_LENGTH (this) | |
600 | - RIGHT_TOTAL_LENGTH (this)); | |
601 | this->total_length += length; | |
602 | this = this->right; | |
603 | } | |
604 | else | |
605 | { | |
606 | /* If we are to use zero-length intervals as buffer pointers, | |
607 | then this code will have to change. */ | |
608 | this->total_length += length; | |
609 | this->position = LEFT_TOTAL_LENGTH (this) | |
610 | + position - relative_position + 1; | |
611 | return tree; | |
612 | } | |
613 | } | |
614 | } | |
90ba40fc JA |
615 | #endif |
616 | ||
617 | /* Effect an adjustment corresponding to the addition of LENGTH characters | |
618 | of text. Do this by finding the interval containing POSITION in the | |
619 | interval tree TREE, and then adjusting all of it's ancestors by adding | |
620 | LENGTH to them. | |
621 | ||
622 | If POSITION is the first character of an interval, meaning that point | |
623 | is actually between the two intervals, make the new text belong to | |
624 | the interval which is "sticky". | |
625 | ||
1d1d7ba0 | 626 | If both intervals are "sticky", then make them belong to the left-most |
90ba40fc JA |
627 | interval. Another possibility would be to create a new interval for |
628 | this text, and make it have the merged properties of both ends. */ | |
629 | ||
630 | static INTERVAL | |
631 | adjust_intervals_for_insertion (tree, position, length) | |
632 | INTERVAL tree; | |
633 | int position, length; | |
634 | { | |
635 | register INTERVAL i; | |
636 | ||
637 | if (TOTAL_LENGTH (tree) == 0) /* Paranoia */ | |
638 | abort (); | |
639 | ||
640 | /* If inserting at point-max of a buffer, that position | |
641 | will be out of range. */ | |
642 | if (position > TOTAL_LENGTH (tree)) | |
643 | position = TOTAL_LENGTH (tree); | |
644 | ||
645 | i = find_interval (tree, position); | |
646 | /* If we are positioned between intervals, check the stickiness of | |
647 | both of them. */ | |
648 | if (position == i->position | |
649 | && position != 1) | |
650 | { | |
651 | register prev = previous_interval (i); | |
652 | ||
653 | /* If both intervals are sticky here, then default to the | |
654 | left-most one. But perhaps we should create a new | |
655 | interval here instead... */ | |
656 | if (END_STICKY (prev)) | |
657 | i = prev; | |
658 | } | |
659 | ||
660 | while (! NULL_INTERVAL_P (i)) | |
661 | { | |
662 | i->total_length += length; | |
663 | i = i->parent | |
664 | } | |
665 | ||
666 | return tree; | |
667 | } | |
a50699fd | 668 | \f |
90ba40fc JA |
669 | /* Delete an node I from its interval tree by merging its subtrees |
670 | into one subtree which is then returned. Caller is responsible for | |
a50699fd JA |
671 | storing the resulting subtree into its parent. */ |
672 | ||
673 | static INTERVAL | |
674 | delete_node (i) | |
675 | register INTERVAL i; | |
676 | { | |
677 | register INTERVAL migrate, this; | |
678 | register int migrate_amt; | |
679 | ||
680 | if (NULL_INTERVAL_P (i->left)) | |
681 | return i->right; | |
682 | if (NULL_INTERVAL_P (i->right)) | |
683 | return i->left; | |
684 | ||
685 | migrate = i->left; | |
686 | migrate_amt = i->left->total_length; | |
687 | this = i->right; | |
688 | this->total_length += migrate_amt; | |
689 | while (! NULL_INTERVAL_P (this->left)) | |
690 | { | |
691 | this = this->left; | |
692 | this->total_length += migrate_amt; | |
693 | } | |
694 | this->left = migrate; | |
695 | migrate->parent = this; | |
696 | ||
697 | return i->right; | |
698 | } | |
699 | ||
700 | /* Delete interval I from its tree by calling `delete_node' | |
701 | and properly connecting the resultant subtree. | |
702 | ||
703 | I is presumed to be empty; that is, no adjustments are made | |
704 | for the length of I. */ | |
705 | ||
706 | void | |
707 | delete_interval (i) | |
708 | register INTERVAL i; | |
709 | { | |
710 | register INTERVAL parent; | |
711 | int amt = LENGTH (i); | |
712 | ||
713 | if (amt > 0) /* Only used on zero-length intervals now. */ | |
714 | abort (); | |
715 | ||
716 | if (ROOT_INTERVAL_P (i)) | |
717 | { | |
718 | Lisp_Object owner = (Lisp_Object) i->parent; | |
719 | parent = delete_node (i); | |
720 | if (! NULL_INTERVAL_P (parent)) | |
721 | parent->parent = (INTERVAL) owner; | |
722 | ||
723 | if (XTYPE (owner) == Lisp_Buffer) | |
724 | XBUFFER (owner)->intervals = parent; | |
725 | else if (XTYPE (owner) == Lisp_String) | |
726 | XSTRING (owner)->intervals = parent; | |
727 | else | |
728 | abort (); | |
729 | ||
730 | return; | |
731 | } | |
732 | ||
733 | parent = i->parent; | |
734 | if (AM_LEFT_CHILD (i)) | |
735 | { | |
736 | parent->left = delete_node (i); | |
737 | if (! NULL_INTERVAL_P (parent->left)) | |
738 | parent->left->parent = parent; | |
739 | } | |
740 | else | |
741 | { | |
742 | parent->right = delete_node (i); | |
743 | if (! NULL_INTERVAL_P (parent->right)) | |
744 | parent->right->parent = parent; | |
745 | } | |
746 | } | |
747 | \f | |
1d1d7ba0 JA |
748 | /* Find the interval in TREE corresponding to the character position FROM |
749 | and delete as much as possible of AMOUNT from that interval, starting | |
750 | after the relative position of FROM within it. Return the amount | |
751 | actually deleted, and if the interval was zeroed-out, delete that | |
752 | interval node from the tree. | |
a50699fd | 753 | |
1d1d7ba0 JA |
754 | Do this by recursing down TREE to the interval in question, and |
755 | deleting the appropriate amount of text. */ | |
a50699fd JA |
756 | |
757 | static int | |
758 | interval_deletion_adjustment (tree, from, amount) | |
759 | register INTERVAL tree; | |
760 | register int from, amount; | |
761 | { | |
762 | register int relative_position = from; | |
763 | ||
764 | if (NULL_INTERVAL_P (tree)) | |
765 | return 0; | |
766 | ||
767 | /* Left branch */ | |
768 | if (relative_position <= LEFT_TOTAL_LENGTH (tree)) | |
769 | { | |
770 | int subtract = interval_deletion_adjustment (tree->left, | |
771 | relative_position, | |
772 | amount); | |
773 | tree->total_length -= subtract; | |
774 | return subtract; | |
775 | } | |
776 | /* Right branch */ | |
777 | else if (relative_position > (TOTAL_LENGTH (tree) | |
778 | - RIGHT_TOTAL_LENGTH (tree))) | |
779 | { | |
780 | int subtract; | |
781 | ||
782 | relative_position -= (tree->total_length | |
783 | - RIGHT_TOTAL_LENGTH (tree)); | |
784 | subtract = interval_deletion_adjustment (tree->right, | |
785 | relative_position, | |
786 | amount); | |
787 | tree->total_length -= subtract; | |
788 | return subtract; | |
789 | } | |
790 | /* Here -- this node */ | |
791 | else | |
792 | { | |
793 | /* If this is a zero-length, marker interval, then | |
794 | we must skip it. */ | |
795 | ||
796 | if (relative_position == LEFT_TOTAL_LENGTH (tree) + 1) | |
797 | { | |
798 | /* This means we're deleting from the beginning of this interval. */ | |
799 | register int my_amount = LENGTH (tree); | |
800 | ||
801 | if (amount < my_amount) | |
802 | { | |
803 | tree->total_length -= amount; | |
804 | return amount; | |
805 | } | |
806 | else | |
807 | { | |
808 | tree->total_length -= my_amount; | |
809 | if (LENGTH (tree) != 0) | |
810 | abort (); /* Paranoia */ | |
811 | ||
812 | delete_interval (tree); | |
813 | return my_amount; | |
814 | } | |
815 | } | |
816 | else /* Deleting starting in the middle. */ | |
817 | { | |
818 | register int my_amount = ((tree->total_length | |
819 | - RIGHT_TOTAL_LENGTH (tree)) | |
820 | - relative_position + 1); | |
821 | ||
822 | if (amount <= my_amount) | |
823 | { | |
824 | tree->total_length -= amount; | |
825 | return amount; | |
826 | } | |
827 | else | |
828 | { | |
829 | tree->total_length -= my_amount; | |
830 | return my_amount; | |
831 | } | |
832 | } | |
833 | } | |
834 | ||
1d1d7ba0 | 835 | /* Never reach here */ |
a50699fd JA |
836 | abort (); |
837 | } | |
838 | ||
1d1d7ba0 JA |
839 | /* Effect the adjustments neccessary to the interval tree of BUFFER |
840 | to correspond to the deletion of LENGTH characters from that buffer | |
841 | text. The deletion is effected at position START (relative to the | |
842 | buffer). */ | |
843 | ||
a50699fd JA |
844 | static void |
845 | adjust_intervals_for_deletion (buffer, start, length) | |
846 | struct buffer *buffer; | |
847 | int start, length; | |
848 | { | |
849 | register int left_to_delete = length; | |
850 | register INTERVAL tree = buffer->intervals; | |
851 | register int deleted; | |
852 | ||
853 | if (NULL_INTERVAL_P (tree)) | |
854 | return; | |
855 | ||
856 | if (length == TOTAL_LENGTH (tree)) | |
857 | { | |
858 | buffer->intervals = NULL_INTERVAL; | |
859 | return; | |
860 | } | |
861 | ||
862 | if (ONLY_INTERVAL_P (tree)) | |
863 | { | |
864 | tree->total_length -= length; | |
865 | return; | |
866 | } | |
867 | ||
868 | if (start > TOTAL_LENGTH (tree)) | |
869 | start = TOTAL_LENGTH (tree); | |
870 | while (left_to_delete > 0) | |
871 | { | |
872 | left_to_delete -= interval_deletion_adjustment (tree, start, | |
873 | left_to_delete); | |
874 | tree = buffer->intervals; | |
875 | if (left_to_delete == tree->total_length) | |
876 | { | |
877 | buffer->intervals = NULL_INTERVAL; | |
878 | return; | |
879 | } | |
880 | } | |
881 | } | |
882 | \f | |
1d1d7ba0 JA |
883 | /* Make the adjustments neccessary to the interval tree of BUFFER to |
884 | represent an addition or deletion of LENGTH characters starting | |
885 | at position START. Addition or deletion is indicated by the sign | |
886 | of LENGTH. */ | |
a50699fd JA |
887 | |
888 | INLINE void | |
889 | offset_intervals (buffer, start, length) | |
890 | struct buffer *buffer; | |
891 | int start, length; | |
892 | { | |
893 | if (NULL_INTERVAL_P (buffer->intervals) || length == 0) | |
894 | return; | |
895 | ||
896 | if (length > 0) | |
897 | adjust_intervals_for_insertion (buffer->intervals, start, length); | |
898 | else | |
899 | adjust_intervals_for_deletion (buffer, start, -length); | |
900 | } | |
9c79dd1b JA |
901 | \f |
902 | /* Merge interval I with its lexicographic successor. The resulting | |
903 | interval is returned, and has the properties of the original | |
904 | successor. The properties of I are lost. I is removed from the | |
905 | interval tree. | |
906 | ||
907 | IMPORTANT: | |
908 | The caller must verify that this is not the last (rightmost) | |
909 | interval. */ | |
910 | ||
911 | INTERVAL | |
912 | merge_interval_right (i) | |
913 | register INTERVAL i; | |
914 | { | |
915 | register int absorb = LENGTH (i); | |
916 | register INTERVAL successor; | |
917 | ||
918 | /* Zero out this interval. */ | |
919 | i->total_length -= absorb; | |
920 | ||
921 | /* Find the succeeding interval. */ | |
922 | if (! NULL_RIGHT_CHILD (i)) /* It's below us. Add absorb | |
923 | as we descend. */ | |
924 | { | |
925 | successor = i->right; | |
926 | while (! NULL_LEFT_CHILD (successor)) | |
927 | { | |
928 | successor->total_length += absorb; | |
929 | successor = successor->left; | |
930 | } | |
931 | ||
932 | successor->total_length += absorb; | |
933 | delete_interval (i); | |
934 | return successor; | |
935 | } | |
936 | ||
937 | successor = i; | |
938 | while (! NULL_PARENT (successor)) /* It's above us. Subtract as | |
939 | we ascend. */ | |
940 | { | |
941 | if (AM_LEFT_CHILD (successor)) | |
942 | { | |
943 | successor = successor->parent; | |
944 | delete_interval (i); | |
945 | return successor; | |
946 | } | |
947 | ||
948 | successor = successor->parent; | |
949 | successor->total_length -= absorb; | |
950 | } | |
951 | ||
952 | /* This must be the rightmost or last interval and cannot | |
953 | be merged right. The caller should have known. */ | |
954 | abort (); | |
955 | } | |
956 | \f | |
957 | /* Merge interval I with its lexicographic predecessor. The resulting | |
958 | interval is returned, and has the properties of the original predecessor. | |
959 | The properties of I are lost. Interval node I is removed from the tree. | |
960 | ||
961 | IMPORTANT: | |
962 | The caller must verify that this is not the first (leftmost) interval. */ | |
963 | ||
964 | INTERVAL | |
965 | merge_interval_left (i) | |
966 | register INTERVAL i; | |
967 | { | |
968 | register int absorb = LENGTH (i); | |
969 | register INTERVAL predecessor; | |
970 | ||
971 | /* Zero out this interval. */ | |
972 | i->total_length -= absorb; | |
973 | ||
974 | /* Find the preceding interval. */ | |
975 | if (! NULL_LEFT_CHILD (i)) /* It's below us. Go down, | |
976 | adding ABSORB as we go. */ | |
977 | { | |
978 | predecessor = i->left; | |
979 | while (! NULL_RIGHT_CHILD (predecessor)) | |
980 | { | |
981 | predecessor->total_length += absorb; | |
982 | predecessor = predecessor->right; | |
983 | } | |
984 | ||
985 | predecessor->total_length += absorb; | |
986 | delete_interval (i); | |
987 | return predecessor; | |
988 | } | |
989 | ||
990 | predecessor = i; | |
991 | while (! NULL_PARENT (predecessor)) /* It's above us. Go up, | |
992 | subtracting ABSORB. */ | |
993 | { | |
994 | if (AM_RIGHT_CHILD (predecessor)) | |
995 | { | |
996 | predecessor = predecessor->parent; | |
997 | delete_interval (i); | |
998 | return predecessor; | |
999 | } | |
1000 | ||
1001 | predecessor = predecessor->parent; | |
1002 | predecessor->total_length -= absorb; | |
1003 | } | |
a50699fd | 1004 | |
9c79dd1b JA |
1005 | /* This must be the leftmost or first interval and cannot |
1006 | be merged left. The caller should have known. */ | |
1007 | abort (); | |
1008 | } | |
1009 | \f | |
1d1d7ba0 JA |
1010 | /* Make an exact copy of interval tree SOURCE which descends from |
1011 | PARENT. This is done by recursing through SOURCE, copying | |
1012 | the current interval and its properties, and then adjusting | |
1013 | the pointers of the copy. */ | |
1014 | ||
a50699fd JA |
1015 | static INTERVAL |
1016 | reproduce_tree (source, parent) | |
1017 | INTERVAL source, parent; | |
1018 | { | |
1019 | register INTERVAL t = make_interval (); | |
1020 | ||
1021 | bcopy (source, t, INTERVAL_SIZE); | |
1022 | copy_properties (source, t); | |
1023 | t->parent = parent; | |
1024 | if (! NULL_LEFT_CHILD (source)) | |
1025 | t->left = reproduce_tree (source->left, t); | |
1026 | if (! NULL_RIGHT_CHILD (source)) | |
1027 | t->right = reproduce_tree (source->right, t); | |
1028 | ||
1029 | return t; | |
1030 | } | |
1031 | ||
1d1d7ba0 JA |
1032 | /* Make a new interval of length LENGTH starting at START in the |
1033 | group of intervals INTERVALS, which is actually an interval tree. | |
1034 | Returns the new interval. | |
1035 | ||
1036 | Generate an error if the new positions would overlap an existing | |
1037 | interval. */ | |
1038 | ||
a50699fd JA |
1039 | static INTERVAL |
1040 | make_new_interval (intervals, start, length) | |
1041 | INTERVAL intervals; | |
1042 | int start, length; | |
1043 | { | |
1044 | INTERVAL slot; | |
1045 | ||
1046 | slot = find_interval (intervals, start); | |
1047 | if (start + length > slot->position + LENGTH (slot)) | |
1048 | error ("Interval would overlap"); | |
1049 | ||
1050 | if (start == slot->position && length == LENGTH (slot)) | |
1051 | return slot; | |
1052 | ||
1053 | if (slot->position == start) | |
1054 | { | |
1055 | /* New right node. */ | |
1056 | split_interval_right (slot, length + 1); | |
1057 | return slot; | |
1058 | } | |
1059 | ||
1060 | if (slot->position + LENGTH (slot) == start + length) | |
1061 | { | |
1062 | /* New left node. */ | |
1063 | split_interval_left (slot, LENGTH (slot) - length + 1); | |
1064 | return slot; | |
1065 | } | |
1066 | ||
1067 | /* Convert interval SLOT into three intervals. */ | |
1068 | split_interval_left (slot, start - slot->position + 1); | |
1069 | split_interval_right (slot, length + 1); | |
1070 | return slot; | |
1071 | } | |
1072 | ||
9c79dd1b | 1073 | /* Insert the intervals of SOURCE into BUFFER at POSITION. |
a50699fd JA |
1074 | |
1075 | This is used in insdel.c when inserting Lisp_Strings into | |
9c79dd1b | 1076 | the buffer. The text corresponding to SOURCE is already in |
a50699fd JA |
1077 | the buffer when this is called. The intervals of new tree are |
1078 | those belonging to the string being inserted; a copy is not made. | |
1079 | ||
1080 | If the inserted text had no intervals associated, this function | |
1081 | simply returns -- offset_intervals should handle placing the | |
90ba40fc | 1082 | text in the correct interval, depending on the sticky bits. |
a50699fd JA |
1083 | |
1084 | If the inserted text had properties (intervals), then there are two | |
1085 | cases -- either insertion happened in the middle of some interval, | |
1086 | or between two intervals. | |
1087 | ||
1088 | If the text goes into the middle of an interval, then new | |
1089 | intervals are created in the middle with only the properties of | |
1090 | the new text, *unless* the macro MERGE_INSERTIONS is true, in | |
1091 | which case the new text has the union of its properties and those | |
1092 | of the text into which it was inserted. | |
1093 | ||
1094 | If the text goes between two intervals, then if neither interval | |
90ba40fc JA |
1095 | had its appropriate sticky property set (front_sticky, rear_sticky), |
1096 | the new text has only its properties. If one of the sticky properties | |
a50699fd JA |
1097 | is set, then the new text "sticks" to that region and its properties |
1098 | depend on merging as above. If both the preceding and succeding | |
90ba40fc JA |
1099 | intervals to the new text are "sticky", then the new text retains |
1100 | only its properties, as if neither sticky property were set. Perhaps | |
a50699fd JA |
1101 | we should consider merging all three sets of properties onto the new |
1102 | text... */ | |
1103 | ||
1104 | void | |
9c79dd1b JA |
1105 | graft_intervals_into_buffer (source, position, buffer) |
1106 | INTERVAL source; | |
a50699fd | 1107 | int position; |
9c79dd1b | 1108 | struct buffer *buffer; |
a50699fd JA |
1109 | { |
1110 | register INTERVAL under, over, this; | |
9c79dd1b | 1111 | register INTERVAL tree = buffer->intervals; |
a50699fd JA |
1112 | |
1113 | /* If the new text has no properties, it becomes part of whatever | |
1114 | interval it was inserted into. */ | |
9c79dd1b | 1115 | if (NULL_INTERVAL_P (source)) |
a50699fd JA |
1116 | return; |
1117 | ||
1118 | /* Paranoia -- the text has already been added, so this buffer | |
1119 | should be of non-zero length. */ | |
1120 | if (TOTAL_LENGTH (tree) == 0) | |
1121 | abort (); | |
1122 | ||
1123 | if (NULL_INTERVAL_P (tree)) | |
1124 | { | |
1125 | /* The inserted text constitutes the whole buffer, so | |
1126 | simply copy over the interval structure. */ | |
9c79dd1b | 1127 | if (BUF_Z (b) == TOTAL_LENGTH (source)) |
a50699fd | 1128 | { |
9c79dd1b | 1129 | buffer->intervals = reproduce_tree (source, tree->parent); |
a50699fd JA |
1130 | /* Explicitly free the old tree here. */ |
1131 | ||
1132 | return; | |
1133 | } | |
1134 | ||
1135 | /* Create an interval tree in which to place a copy | |
1136 | of the intervals of the inserted string. */ | |
1137 | { | |
1138 | Lisp_Object buffer; | |
1139 | XSET (buffer, Lisp_Buffer, b); | |
1140 | create_root_interval (buffer); | |
1141 | } | |
1142 | } | |
1143 | else | |
9c79dd1b | 1144 | if (TOTAL_LENGTH (tree) == TOTAL_LENGTH (source)) |
a50699fd JA |
1145 | |
1146 | /* If the buffer contains only the new string, but | |
1147 | there was already some interval tree there, then it may be | |
1148 | some zero length intervals. Eventually, do something clever | |
1149 | about inserting properly. For now, just waste the old intervals. */ | |
1150 | { | |
9c79dd1b | 1151 | buffer->intervals = reproduce_tree (source, tree->parent); |
a50699fd JA |
1152 | /* Explicitly free the old tree here. */ |
1153 | ||
1154 | return; | |
1155 | } | |
1156 | ||
1157 | this = under = find_interval (tree, position); | |
1158 | if (NULL_INTERVAL_P (under)) /* Paranoia */ | |
1159 | abort (); | |
9c79dd1b | 1160 | over = find_interval (source, 1); |
a50699fd JA |
1161 | |
1162 | /* Insertion between intervals */ | |
1163 | if (position == under->position) | |
1164 | { | |
1165 | /* First interval -- none precede it. */ | |
1166 | if (position == 1) | |
1167 | { | |
90ba40fc | 1168 | if (! FRONT_STICKY (under)) |
a50699fd JA |
1169 | /* The inserted string keeps its own properties. */ |
1170 | while (! NULL_INTERVAL_P (over)) | |
1171 | { | |
1172 | position = LENGTH (over) + 1; | |
1173 | this = split_interval_left (this, position); | |
1174 | copy_properties (over, this); | |
1175 | over = next_interval (over); | |
1176 | } | |
1177 | else | |
9c79dd1b JA |
1178 | /* This string "sticks" to the first interval, `under', |
1179 | which means it gets those properties. */ | |
a50699fd JA |
1180 | while (! NULL_INTERVAL_P (over)) |
1181 | { | |
1182 | position = LENGTH (over) + 1; | |
1183 | this = split_interval_left (this, position); | |
1184 | copy_properties (under, this); | |
1185 | if (MERGE_INSERTIONS (under)) | |
1186 | merge_properties (over, this); | |
1187 | over = next_interval (over); | |
1188 | } | |
1189 | } | |
1190 | else | |
1191 | { | |
1192 | INTERVAL prev = previous_interval (under); | |
1193 | if (NULL_INTERVAL_P (prev)) | |
1194 | abort (); | |
1195 | ||
90ba40fc | 1196 | if (END_STICKY (prev)) |
a50699fd | 1197 | { |
90ba40fc JA |
1198 | if (FRONT_STICKY (under)) |
1199 | /* The intervals go inbetween as the two sticky | |
a50699fd JA |
1200 | properties cancel each other. Should we change |
1201 | this policy? */ | |
1202 | while (! NULL_INTERVAL_P (over)) | |
1203 | { | |
1204 | position = LENGTH (over) + 1; | |
1205 | this = split_interval_left (this, position); | |
1206 | copy_properties (over, this); | |
1207 | over = next_interval (over); | |
1208 | } | |
1209 | else | |
1210 | /* The intervals stick to prev */ | |
1211 | while (! NULL_INTERVAL_P (over)) | |
1212 | { | |
1213 | position = LENGTH (over) + 1; | |
1214 | this = split_interval_left (this, position); | |
1215 | copy_properties (prev, this); | |
1216 | if (MERGE_INSERTIONS (prev)) | |
1217 | merge_properties (over, this); | |
1218 | over = next_interval (over); | |
1219 | } | |
1220 | } | |
1221 | else | |
1222 | { | |
90ba40fc | 1223 | if (FRONT_STICKY (under)) |
9c79dd1b JA |
1224 | /* The inserted text "sticks" to the interval `under', |
1225 | which means it gets those properties. */ | |
a50699fd JA |
1226 | while (! NULL_INTERVAL_P (over)) |
1227 | { | |
1228 | position = LENGTH (over) + 1; | |
1229 | this = split_interval_left (this, position); | |
1230 | copy_properties (under, this); | |
1231 | if (MERGE_INSERTIONS (under)) | |
1232 | merge_properties (over, this); | |
1233 | over = next_interval (over); | |
1234 | } | |
1235 | else | |
1236 | /* The intervals go inbetween */ | |
1237 | while (! NULL_INTERVAL_P (over)) | |
1238 | { | |
1239 | position = LENGTH (over) + 1; | |
1240 | this = split_interval_left (this, position); | |
1241 | copy_properties (over, this); | |
1242 | over = next_interval (over); | |
1243 | } | |
1244 | } | |
1245 | } | |
1246 | ||
9c79dd1b | 1247 | buffer->intervals = balance_intervals (buffer->intervals); |
a50699fd JA |
1248 | return; |
1249 | } | |
1250 | ||
1251 | /* Here for insertion in the middle of an interval. */ | |
1252 | ||
9c79dd1b | 1253 | if (TOTAL_LENGTH (source) < LENGTH (this)) |
a50699fd JA |
1254 | { |
1255 | INTERVAL end_unchanged | |
9c79dd1b | 1256 | = split_interval_right (this, TOTAL_LENGTH (source) + 1); |
a50699fd JA |
1257 | copy_properties (under, end_unchanged); |
1258 | } | |
1259 | ||
1260 | position = position - tree->position + 1; | |
1261 | while (! NULL_INTERVAL_P (over)) | |
1262 | { | |
1263 | this = split_interval_right (under, position); | |
1264 | copy_properties (over, this); | |
1265 | if (MERGE_INSERTIONS (under)) | |
1266 | merge_properties (under, this); | |
1267 | ||
1268 | position = LENGTH (over) + 1; | |
1269 | over = next_interval (over); | |
1270 | } | |
1271 | ||
9c79dd1b | 1272 | buffer->intervals = balance_intervals (buffer->intervals); |
a50699fd JA |
1273 | return; |
1274 | } | |
1275 | ||
a50699fd JA |
1276 | /* Set point in BUFFER to POSITION. If the target position is in |
1277 | an invisible interval which is not displayed with a special glyph, | |
1278 | skip intervals until we find one. Point may be at the first | |
1279 | position of an invisible interval, if it is displayed with a | |
d7e3e52b | 1280 | special glyph. */ |
a50699fd JA |
1281 | |
1282 | void | |
1283 | set_point (position, buffer) | |
1284 | register int position; | |
1285 | register struct buffer *buffer; | |
1286 | { | |
1287 | register INTERVAL to, from, target; | |
1288 | register int iposition = position; | |
1289 | int buffer_point; | |
1290 | register Lisp_Object obj; | |
1291 | int backwards = (position < BUF_PT (buffer)) ? 1 : 0; | |
9c79dd1b | 1292 | int old_position = buffer->text.pt; |
a50699fd JA |
1293 | |
1294 | if (position == buffer->text.pt) | |
1295 | return; | |
1296 | ||
1297 | if (NULL_INTERVAL_P (buffer->intervals)) | |
1298 | { | |
1299 | buffer->text.pt = position; | |
1300 | return; | |
1301 | } | |
1302 | ||
1303 | /* Perhaps we should just change `position' to the limit. */ | |
1304 | if (position > BUF_Z (buffer) || position < BUF_BEG (buffer)) | |
1305 | abort (); | |
1306 | ||
1307 | /* Position Z is really one past the last char in the buffer. */ | |
1308 | if (position == BUF_Z (buffer)) | |
1309 | iposition = position - 1; | |
1310 | ||
1311 | to = find_interval (buffer->intervals, iposition); | |
1312 | buffer_point =(BUF_PT (buffer) == BUF_Z (buffer) | |
1313 | ? BUF_Z (buffer) - 1 | |
1314 | : BUF_PT (buffer)); | |
9c79dd1b JA |
1315 | |
1316 | /* We could cache this and save time. */ | |
a50699fd | 1317 | from = find_interval (buffer->intervals, buffer_point); |
9c79dd1b | 1318 | |
a50699fd JA |
1319 | if (NULL_INTERVAL_P (to) || NULL_INTERVAL_P (from)) |
1320 | abort (); /* Paranoia */ | |
1321 | ||
1322 | /* Moving within an interval */ | |
1323 | if (to == from && INTERVAL_VISIBLE_P (to)) | |
1324 | { | |
1325 | buffer->text.pt = position; | |
1326 | return; | |
1327 | } | |
1328 | ||
1329 | /* Here for the case of moving into another interval. */ | |
1330 | ||
1331 | target = to; | |
1332 | while (! INTERVAL_VISIBLE_P (to) && ! DISPLAY_INVISIBLE_GLYPH (to) | |
1333 | && ! NULL_INTERVAL_P (to)) | |
1334 | to = (backwards ? previous_interval (to) : next_interval (to)); | |
1335 | if (NULL_INTERVAL_P (to)) | |
1336 | return; | |
1337 | ||
1338 | /* Here we know we are actually moving to another interval. */ | |
1339 | if (INTERVAL_VISIBLE_P (to)) | |
1340 | { | |
1341 | /* If we skipped some intervals, go to the closest point | |
1342 | in the interval we've stopped at. */ | |
1343 | if (to != target) | |
1344 | buffer->text.pt = (backwards | |
1345 | ? to->position + LENGTH (to) - 1 | |
1346 | : to->position); | |
1347 | else | |
1348 | buffer->text.pt = position; | |
1349 | } | |
1350 | else | |
1351 | buffer->text.pt = to->position; | |
1352 | ||
d7e3e52b JA |
1353 | /* We run point-left and point-entered hooks here, iff the |
1354 | two intervals are not equivalent. These hooks take | |
1355 | (old_point, new_point) as arguments. */ | |
9c79dd1b JA |
1356 | if (! intervals_equal (from, to)) |
1357 | { | |
1358 | Lisp_Object val; | |
1359 | ||
1360 | val = Fget (Qpoint_left, from->plist); | |
1361 | if (! NILP (val)) | |
1362 | call2 (val, old_position, position); | |
1363 | ||
1364 | val = Fget (Qpoint_entered, to->plist); | |
1365 | if (! NILP (val)) | |
1366 | call2 (val, old_position, position); | |
1367 | } | |
a50699fd JA |
1368 | } |
1369 | ||
9c79dd1b | 1370 | /* Set point temporarily, without checking any text properties. */ |
a50699fd | 1371 | |
9c79dd1b JA |
1372 | INLINE void |
1373 | temp_set_point (position, buffer) | |
1374 | int position; | |
1375 | struct buffer *buffer; | |
1376 | { | |
1377 | buffer->text.pt = position; | |
1378 | } | |
1379 | ||
1380 | /* Check for read-only intervals and signal an error if we find one. | |
1381 | Then check for any modification hooks in the range START up to | |
1382 | (but not including) TO. Create a list of all these hooks in | |
1383 | lexicographic order, eliminating consecutive extra copies of the | |
1384 | same hook. Then call those hooks in order, with START and END - 1 | |
1385 | as arguments. */ | |
a50699fd JA |
1386 | |
1387 | void | |
1388 | verify_interval_modification (buf, start, end) | |
1389 | struct buffer *buf; | |
1390 | int start, end; | |
1391 | { | |
1392 | register INTERVAL intervals = buf->intervals; | |
1393 | register INTERVAL i; | |
1394 | register Lisp_Object hooks = Qnil; | |
9c79dd1b JA |
1395 | register prev_mod_hook = Qnil; |
1396 | register Lisp_Object mod_hook; | |
1397 | struct gcpro gcpro1; | |
a50699fd JA |
1398 | |
1399 | if (NULL_INTERVAL_P (intervals)) | |
1400 | return; | |
1401 | ||
1402 | if (start > end) | |
1403 | { | |
1404 | int temp = start; | |
1405 | start = end; | |
1406 | end = temp; | |
1407 | } | |
1408 | ||
1409 | if (start == BUF_Z (buf)) | |
1410 | { | |
9c79dd1b | 1411 | /* This should not be getting called on empty buffers. */ |
a50699fd JA |
1412 | if (BUF_Z (buf) == 1) |
1413 | abort (); | |
1414 | ||
1415 | i = find_interval (intervals, start - 1); | |
90ba40fc | 1416 | if (! END_STICKY_P (i)) |
a50699fd JA |
1417 | return; |
1418 | } | |
1419 | else | |
1420 | i = find_interval (intervals, start); | |
1421 | ||
1422 | do | |
1423 | { | |
a50699fd | 1424 | if (! INTERVAL_WRITABLE_P (i)) |
9c79dd1b JA |
1425 | error ("Attempt to modify read-only text"); |
1426 | ||
a50699fd | 1427 | mod_hook = Fget (Qmodification, i->plist); |
9c79dd1b JA |
1428 | if (! NILP (mod_hook) && ! EQ (mod_hook, prev_mod_hook)) |
1429 | { | |
1430 | hooks = Fcons (mod_hook, hooks); | |
1431 | prev_mod_hook = mod_hook; | |
1432 | } | |
1433 | ||
a50699fd JA |
1434 | i = next_interval (i); |
1435 | } | |
1436 | while (! NULL_INTERVAL_P (i) && i->position <= end); | |
1437 | ||
9c79dd1b | 1438 | GCPRO1 (hooks); |
a50699fd JA |
1439 | hooks = Fnreverse (hooks); |
1440 | while (! EQ (hooks, Qnil)) | |
9c79dd1b JA |
1441 | { |
1442 | call2 (Fcar (hooks), start, end - 1); | |
1443 | hooks = Fcdr (hooks); | |
1444 | } | |
1445 | UNGCPRO; | |
a50699fd JA |
1446 | } |
1447 | ||
1448 | /* Balance an interval node if the amount of text in its left and right | |
1449 | subtrees differs by more than the percentage specified by | |
1450 | `interval-balance-threshold'. */ | |
1451 | ||
1452 | static INTERVAL | |
1453 | balance_an_interval (i) | |
1454 | INTERVAL i; | |
1455 | { | |
1456 | register int total_children_size = (LEFT_TOTAL_LENGTH (i) | |
1457 | + RIGHT_TOTAL_LENGTH (i)); | |
1458 | register int threshold = (XFASTINT (interval_balance_threshold) | |
1459 | * (total_children_size / 100)); | |
1460 | ||
1461 | if (LEFT_TOTAL_LENGTH (i) > RIGHT_TOTAL_LENGTH (i) | |
1462 | && (LEFT_TOTAL_LENGTH (i) - RIGHT_TOTAL_LENGTH (i)) > threshold) | |
1463 | return rotate_right (i); | |
1464 | ||
1465 | if (LEFT_TOTAL_LENGTH (i) > RIGHT_TOTAL_LENGTH (i) | |
1466 | && (LEFT_TOTAL_LENGTH (i) - RIGHT_TOTAL_LENGTH (i)) > threshold) | |
1467 | return rotate_right (i); | |
1468 | ||
1469 | #if 0 | |
1470 | if (LEFT_TOTAL_LENGTH (i) > | |
1471 | (RIGHT_TOTAL_LENGTH (i) + XINT (interval_balance_threshold))) | |
1472 | return rotate_right (i); | |
1473 | ||
1474 | if (RIGHT_TOTAL_LENGTH (i) > | |
1475 | (LEFT_TOTAL_LENGTH (i) + XINT (interval_balance_threshold))) | |
1476 | return rotate_left (i); | |
1477 | #endif | |
1478 | ||
1479 | return i; | |
1480 | } | |
1481 | ||
1482 | /* Balance the interval tree TREE. Balancing is by weight | |
1483 | (the amount of text). */ | |
1484 | ||
1485 | INTERVAL | |
1486 | balance_intervals (tree) | |
1487 | register INTERVAL tree; | |
1488 | { | |
1489 | register INTERVAL new_tree; | |
1490 | ||
1491 | if (NULL_INTERVAL_P (tree)) | |
1492 | return NULL_INTERVAL; | |
1493 | ||
1494 | new_tree = tree; | |
1495 | do | |
1496 | { | |
1497 | tree = new_tree; | |
1498 | new_tree = balance_an_interval (new_tree); | |
1499 | } | |
1500 | while (new_tree != tree); | |
1501 | ||
1502 | return new_tree; | |
1503 | } | |
1504 | ||
9c79dd1b | 1505 | /* Produce an interval tree reflecting the intervals in |
a50699fd JA |
1506 | TREE from START to START + LENGTH. */ |
1507 | ||
1508 | static INTERVAL | |
1509 | copy_intervals (tree, start, length) | |
1510 | INTERVAL tree; | |
1511 | int start, length; | |
1512 | { | |
1513 | register INTERVAL i, new, t; | |
1514 | register int got; | |
1515 | ||
1516 | if (NULL_INTERVAL_P (tree) || length <= 0) | |
1517 | return NULL_INTERVAL; | |
1518 | ||
1519 | i = find_interval (tree, start); | |
1520 | if (NULL_INTERVAL_P (i) || LENGTH (i) == 0) | |
1521 | abort (); | |
1522 | ||
1523 | /* If there is only one interval and it's the default, return nil. */ | |
1524 | if ((start - i->position + 1 + length) < LENGTH (i) | |
1525 | && DEFAULT_INTERVAL_P (i)) | |
1526 | return NULL_INTERVAL; | |
1527 | ||
1528 | new = make_interval (); | |
1529 | new->position = 1; | |
1530 | got = (LENGTH (i) - (start - i->position)); | |
9c79dd1b | 1531 | new->total_length = length; |
a50699fd JA |
1532 | copy_properties (i, new); |
1533 | ||
1534 | t = new; | |
1535 | while (got < length) | |
1536 | { | |
1537 | i = next_interval (i); | |
9c79dd1b | 1538 | t = split_interval_right (t, got + 1); |
a50699fd JA |
1539 | copy_properties (i, t); |
1540 | got += LENGTH (i); | |
1541 | } | |
1542 | ||
1543 | if (got > length) | |
1544 | t->total_length -= (got - length); | |
1545 | ||
1546 | return balance_intervals (new); | |
1547 | } | |
1548 | ||
a50699fd JA |
1549 | /* Give STRING the properties of BUFFER from POSITION to LENGTH. */ |
1550 | ||
d7e3e52b | 1551 | INLINE void |
a50699fd JA |
1552 | copy_intervals_to_string (string, buffer, position, length) |
1553 | Lisp_Object string, buffer; | |
1554 | int position, length; | |
1555 | { | |
1556 | INTERVAL interval_copy = copy_intervals (XBUFFER (buffer)->intervals, | |
1557 | position, length); | |
1558 | if (NULL_INTERVAL_P (interval_copy)) | |
1559 | return; | |
1560 | ||
1561 | interval_copy->parent = (INTERVAL) string; | |
1562 | XSTRING (string)->intervals = interval_copy; | |
1563 | } |