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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 JA |
370 | new->parent = interval; |
371 | #if 0 | |
372 | copy_properties (interval, new); | |
373 | #endif | |
374 | ||
375 | if (LEAF_INTERVAL_P (interval) || NULL_RIGHT_CHILD (interval)) | |
376 | { | |
377 | interval->right = new; | |
378 | new->total_length = new_length; | |
379 | ||
380 | return new; | |
381 | } | |
382 | ||
383 | /* Insert the new node between INTERVAL and its right child. */ | |
384 | new->right = interval->right; | |
385 | interval->right->parent = new; | |
386 | interval->right = new; | |
387 | ||
388 | new->total_length = new_length + new->right->total_length; | |
389 | ||
390 | return new; | |
391 | } | |
392 | ||
90ba40fc JA |
393 | /* Split INTERVAL into two pieces, starting the second piece at character |
394 | position OFFSET (counting from 1), relative to INTERVAL. The left-hand | |
395 | piece (first, lexicographically) is returned. | |
a50699fd | 396 | |
90ba40fc JA |
397 | The size and position fields of the two intervals are set based upon |
398 | those of the original interval. The property list of the new interval | |
399 | is reset, thus it is up to the caller to do the right thing with the | |
400 | result. | |
401 | ||
402 | Note that this does not change the position of INTERVAL; if it is a root, | |
403 | it is still a root after this operation. */ | |
a50699fd JA |
404 | |
405 | INTERVAL | |
90ba40fc | 406 | split_interval_left (interval, offset) |
a50699fd | 407 | INTERVAL interval; |
90ba40fc | 408 | int offset; |
a50699fd JA |
409 | { |
410 | INTERVAL new = make_interval (); | |
411 | int position = interval->position; | |
90ba40fc | 412 | int new_length = offset - 1; |
a50699fd JA |
413 | |
414 | #if 0 | |
415 | copy_properties (interval, new); | |
416 | #endif | |
417 | ||
418 | new->position = interval->position; | |
419 | ||
90ba40fc | 420 | interval->position = interval->position + offset - 1; |
a50699fd JA |
421 | new->parent = interval; |
422 | ||
423 | if (NULL_LEFT_CHILD (interval)) | |
424 | { | |
425 | interval->left = new; | |
426 | new->total_length = new_length; | |
427 | ||
428 | return new; | |
429 | } | |
430 | ||
431 | /* Insert the new node between INTERVAL and its left child. */ | |
432 | new->left = interval->left; | |
433 | new->left->parent = new; | |
434 | interval->left = new; | |
435 | new->total_length = LENGTH (new) + LEFT_TOTAL_LENGTH (new); | |
436 | ||
437 | return new; | |
438 | } | |
439 | \f | |
90ba40fc JA |
440 | /* Find the interval containing text position POSITION in the text |
441 | represented by the interval tree TREE. POSITION is relative to | |
442 | the beginning of that text. | |
a50699fd | 443 | |
90ba40fc JA |
444 | The `position' field, which is a cache of an interval's position, |
445 | is updated in the interval found. Other functions (e.g., next_interval) | |
446 | will update this cache based on the result of find_interval. */ | |
447 | ||
448 | INLINE INTERVAL | |
a50699fd JA |
449 | find_interval (tree, position) |
450 | register INTERVAL tree; | |
451 | register int position; | |
452 | { | |
453 | register int relative_position = position; | |
454 | ||
455 | if (NULL_INTERVAL_P (tree)) | |
456 | return NULL_INTERVAL; | |
457 | ||
458 | if (position > TOTAL_LENGTH (tree)) | |
459 | abort (); /* Paranoia */ | |
460 | #if 0 | |
461 | position = TOTAL_LENGTH (tree); | |
462 | #endif | |
463 | ||
464 | while (1) | |
465 | { | |
466 | if (relative_position <= LEFT_TOTAL_LENGTH (tree)) | |
467 | { | |
468 | tree = tree->left; | |
469 | } | |
470 | else if (relative_position > (TOTAL_LENGTH (tree) | |
471 | - RIGHT_TOTAL_LENGTH (tree))) | |
472 | { | |
473 | relative_position -= (TOTAL_LENGTH (tree) | |
474 | - RIGHT_TOTAL_LENGTH (tree)); | |
475 | tree = tree->right; | |
476 | } | |
477 | else | |
478 | { | |
479 | tree->position = LEFT_TOTAL_LENGTH (tree) | |
480 | + position - relative_position + 1; | |
481 | return tree; | |
482 | } | |
483 | } | |
484 | } | |
485 | \f | |
486 | /* Find the succeeding interval (lexicographically) to INTERVAL. | |
90ba40fc JA |
487 | Sets the `position' field based on that of INTERVAL (see |
488 | find_interval). */ | |
a50699fd JA |
489 | |
490 | INTERVAL | |
491 | next_interval (interval) | |
492 | register INTERVAL interval; | |
493 | { | |
494 | register INTERVAL i = interval; | |
495 | register int next_position; | |
496 | ||
497 | if (NULL_INTERVAL_P (i)) | |
498 | return NULL_INTERVAL; | |
499 | next_position = interval->position + LENGTH (interval); | |
500 | ||
501 | if (! NULL_RIGHT_CHILD (i)) | |
502 | { | |
503 | i = i->right; | |
504 | while (! NULL_LEFT_CHILD (i)) | |
505 | i = i->left; | |
506 | ||
507 | i->position = next_position; | |
508 | return i; | |
509 | } | |
510 | ||
511 | while (! NULL_PARENT (i)) | |
512 | { | |
513 | if (AM_LEFT_CHILD (i)) | |
514 | { | |
515 | i = i->parent; | |
516 | i->position = next_position; | |
517 | return i; | |
518 | } | |
519 | ||
520 | i = i->parent; | |
521 | } | |
522 | ||
523 | return NULL_INTERVAL; | |
524 | } | |
525 | ||
526 | /* Find the preceding interval (lexicographically) to INTERVAL. | |
90ba40fc JA |
527 | Sets the `position' field based on that of INTERVAL (see |
528 | find_interval). */ | |
a50699fd JA |
529 | |
530 | INTERVAL | |
531 | previous_interval (interval) | |
532 | register INTERVAL interval; | |
533 | { | |
534 | register INTERVAL i; | |
535 | register position_of_previous; | |
536 | ||
537 | if (NULL_INTERVAL_P (interval)) | |
538 | return NULL_INTERVAL; | |
539 | ||
540 | if (! NULL_LEFT_CHILD (interval)) | |
541 | { | |
542 | i = interval->left; | |
543 | while (! NULL_RIGHT_CHILD (i)) | |
544 | i = i->right; | |
545 | ||
546 | i->position = interval->position - LENGTH (i); | |
547 | return i; | |
548 | } | |
549 | ||
550 | i = interval; | |
551 | while (! NULL_PARENT (i)) | |
552 | { | |
553 | if (AM_RIGHT_CHILD (i)) | |
554 | { | |
555 | i = i->parent; | |
556 | ||
557 | i->position = interval->position - LENGTH (i); | |
558 | return i; | |
559 | } | |
560 | i = i->parent; | |
561 | } | |
562 | ||
563 | return NULL_INTERVAL; | |
564 | } | |
565 | \f | |
90ba40fc | 566 | #if 0 |
a50699fd JA |
567 | /* Traverse a path down the interval tree TREE to the interval |
568 | containing POSITION, adjusting all nodes on the path for | |
569 | an addition of LENGTH characters. Insertion between two intervals | |
570 | (i.e., point == i->position, where i is second interval) means | |
571 | text goes into second interval. | |
572 | ||
573 | Modifications are needed to handle the hungry bits -- after simply | |
574 | finding the interval at position (don't add length going down), | |
575 | if it's the beginning of the interval, get the previous interval | |
576 | and check the hugry bits of both. Then add the length going back up | |
577 | to the root. */ | |
578 | ||
579 | static INTERVAL | |
580 | adjust_intervals_for_insertion (tree, position, length) | |
581 | INTERVAL tree; | |
582 | int position, length; | |
583 | { | |
584 | register int relative_position; | |
585 | register INTERVAL this; | |
586 | ||
587 | if (TOTAL_LENGTH (tree) == 0) /* Paranoia */ | |
588 | abort (); | |
589 | ||
590 | /* If inserting at point-max of a buffer, that position | |
591 | will be out of range */ | |
592 | if (position > TOTAL_LENGTH (tree)) | |
593 | position = TOTAL_LENGTH (tree); | |
594 | relative_position = position; | |
595 | this = tree; | |
596 | ||
597 | while (1) | |
598 | { | |
599 | if (relative_position <= LEFT_TOTAL_LENGTH (this)) | |
600 | { | |
601 | this->total_length += length; | |
602 | this = this->left; | |
603 | } | |
604 | else if (relative_position > (TOTAL_LENGTH (this) | |
605 | - RIGHT_TOTAL_LENGTH (this))) | |
606 | { | |
607 | relative_position -= (TOTAL_LENGTH (this) | |
608 | - RIGHT_TOTAL_LENGTH (this)); | |
609 | this->total_length += length; | |
610 | this = this->right; | |
611 | } | |
612 | else | |
613 | { | |
614 | /* If we are to use zero-length intervals as buffer pointers, | |
615 | then this code will have to change. */ | |
616 | this->total_length += length; | |
617 | this->position = LEFT_TOTAL_LENGTH (this) | |
618 | + position - relative_position + 1; | |
619 | return tree; | |
620 | } | |
621 | } | |
622 | } | |
90ba40fc JA |
623 | #endif |
624 | ||
625 | /* Effect an adjustment corresponding to the addition of LENGTH characters | |
626 | of text. Do this by finding the interval containing POSITION in the | |
627 | interval tree TREE, and then adjusting all of it's ancestors by adding | |
628 | LENGTH to them. | |
629 | ||
630 | If POSITION is the first character of an interval, meaning that point | |
631 | is actually between the two intervals, make the new text belong to | |
632 | the interval which is "sticky". | |
633 | ||
1d1d7ba0 | 634 | If both intervals are "sticky", then make them belong to the left-most |
90ba40fc JA |
635 | interval. Another possibility would be to create a new interval for |
636 | this text, and make it have the merged properties of both ends. */ | |
637 | ||
638 | static INTERVAL | |
639 | adjust_intervals_for_insertion (tree, position, length) | |
640 | INTERVAL tree; | |
641 | int position, length; | |
642 | { | |
643 | register INTERVAL i; | |
644 | ||
645 | if (TOTAL_LENGTH (tree) == 0) /* Paranoia */ | |
646 | abort (); | |
647 | ||
648 | /* If inserting at point-max of a buffer, that position | |
649 | will be out of range. */ | |
650 | if (position > TOTAL_LENGTH (tree)) | |
651 | position = TOTAL_LENGTH (tree); | |
652 | ||
653 | i = find_interval (tree, position); | |
654 | /* If we are positioned between intervals, check the stickiness of | |
655 | both of them. */ | |
656 | if (position == i->position | |
657 | && position != 1) | |
658 | { | |
659 | register prev = previous_interval (i); | |
660 | ||
661 | /* If both intervals are sticky here, then default to the | |
662 | left-most one. But perhaps we should create a new | |
663 | interval here instead... */ | |
664 | if (END_STICKY (prev)) | |
665 | i = prev; | |
666 | } | |
667 | ||
668 | while (! NULL_INTERVAL_P (i)) | |
669 | { | |
670 | i->total_length += length; | |
671 | i = i->parent | |
672 | } | |
673 | ||
674 | return tree; | |
675 | } | |
a50699fd JA |
676 | \f |
677 | /* Merge interval I with its lexicographic successor. Note that | |
678 | this does not deal with the properties, or delete I. */ | |
679 | ||
680 | INTERVAL | |
681 | merge_interval_right (i) | |
682 | register INTERVAL i; | |
683 | { | |
684 | register int absorb = LENGTH (i); | |
685 | ||
686 | /* Zero out this interval. */ | |
687 | i->total_length -= absorb; | |
688 | ||
689 | /* Find the succeeding interval. */ | |
690 | if (! NULL_RIGHT_CHILD (i)) /* It's below us. Add absorb | |
691 | as we descend. */ | |
692 | { | |
693 | i = i->right; | |
694 | while (! NULL_LEFT_CHILD (i)) | |
695 | { | |
696 | i->total_length += absorb; | |
697 | i = i->left; | |
698 | } | |
699 | ||
700 | i->total_length += absorb; | |
701 | return i; | |
702 | } | |
703 | ||
704 | while (! NULL_PARENT (i)) /* It's above us. Subtract as | |
705 | we ascend. */ | |
706 | { | |
707 | if (AM_LEFT_CHILD (i)) | |
708 | { | |
709 | i = i->parent; | |
710 | return i; | |
711 | } | |
712 | ||
713 | i = i->parent; | |
714 | i->total_length -= absorb; | |
715 | } | |
716 | ||
717 | return NULL_INTERVAL; | |
718 | } | |
719 | \f | |
720 | /* Merge interval I with its lexicographic predecessor. Note that | |
721 | this does not deal with the properties, or delete I.*/ | |
722 | ||
723 | INTERVAL | |
724 | merge_interval_left (i) | |
725 | register INTERVAL i; | |
726 | { | |
727 | register int absorb = LENGTH (i); | |
728 | ||
729 | /* Zero out this interval. */ | |
730 | i->total_length -= absorb; | |
731 | ||
732 | /* Find the preceding interval. */ | |
733 | if (! NULL_LEFT_CHILD (i)) /* It's below us. Go down, | |
734 | adding ABSORB as we go. */ | |
735 | { | |
736 | i = i->left; | |
737 | while (! NULL_RIGHT_CHILD (i)) | |
738 | { | |
739 | i->total_length += absorb; | |
740 | i = i->right; | |
741 | } | |
742 | ||
743 | i->total_length += absorb; | |
744 | return i; | |
745 | } | |
746 | ||
747 | while (! NULL_PARENT (i)) /* It's above us. Go up, | |
748 | subtracting ABSORB. */ | |
749 | { | |
750 | if (AM_RIGHT_CHILD (i)) | |
751 | { | |
752 | i = i->parent; | |
753 | return i; | |
754 | } | |
755 | ||
756 | i = i->parent; | |
757 | i->total_length -= absorb; | |
758 | } | |
759 | ||
760 | return NULL_INTERVAL; | |
761 | } | |
762 | \f | |
90ba40fc JA |
763 | /* Delete an node I from its interval tree by merging its subtrees |
764 | into one subtree which is then returned. Caller is responsible for | |
a50699fd JA |
765 | storing the resulting subtree into its parent. */ |
766 | ||
767 | static INTERVAL | |
768 | delete_node (i) | |
769 | register INTERVAL i; | |
770 | { | |
771 | register INTERVAL migrate, this; | |
772 | register int migrate_amt; | |
773 | ||
774 | if (NULL_INTERVAL_P (i->left)) | |
775 | return i->right; | |
776 | if (NULL_INTERVAL_P (i->right)) | |
777 | return i->left; | |
778 | ||
779 | migrate = i->left; | |
780 | migrate_amt = i->left->total_length; | |
781 | this = i->right; | |
782 | this->total_length += migrate_amt; | |
783 | while (! NULL_INTERVAL_P (this->left)) | |
784 | { | |
785 | this = this->left; | |
786 | this->total_length += migrate_amt; | |
787 | } | |
788 | this->left = migrate; | |
789 | migrate->parent = this; | |
790 | ||
791 | return i->right; | |
792 | } | |
793 | ||
794 | /* Delete interval I from its tree by calling `delete_node' | |
795 | and properly connecting the resultant subtree. | |
796 | ||
797 | I is presumed to be empty; that is, no adjustments are made | |
798 | for the length of I. */ | |
799 | ||
800 | void | |
801 | delete_interval (i) | |
802 | register INTERVAL i; | |
803 | { | |
804 | register INTERVAL parent; | |
805 | int amt = LENGTH (i); | |
806 | ||
807 | if (amt > 0) /* Only used on zero-length intervals now. */ | |
808 | abort (); | |
809 | ||
810 | if (ROOT_INTERVAL_P (i)) | |
811 | { | |
812 | Lisp_Object owner = (Lisp_Object) i->parent; | |
813 | parent = delete_node (i); | |
814 | if (! NULL_INTERVAL_P (parent)) | |
815 | parent->parent = (INTERVAL) owner; | |
816 | ||
817 | if (XTYPE (owner) == Lisp_Buffer) | |
818 | XBUFFER (owner)->intervals = parent; | |
819 | else if (XTYPE (owner) == Lisp_String) | |
820 | XSTRING (owner)->intervals = parent; | |
821 | else | |
822 | abort (); | |
823 | ||
824 | return; | |
825 | } | |
826 | ||
827 | parent = i->parent; | |
828 | if (AM_LEFT_CHILD (i)) | |
829 | { | |
830 | parent->left = delete_node (i); | |
831 | if (! NULL_INTERVAL_P (parent->left)) | |
832 | parent->left->parent = parent; | |
833 | } | |
834 | else | |
835 | { | |
836 | parent->right = delete_node (i); | |
837 | if (! NULL_INTERVAL_P (parent->right)) | |
838 | parent->right->parent = parent; | |
839 | } | |
840 | } | |
841 | \f | |
1d1d7ba0 JA |
842 | /* Find the interval in TREE corresponding to the character position FROM |
843 | and delete as much as possible of AMOUNT from that interval, starting | |
844 | after the relative position of FROM within it. Return the amount | |
845 | actually deleted, and if the interval was zeroed-out, delete that | |
846 | interval node from the tree. | |
a50699fd | 847 | |
1d1d7ba0 JA |
848 | Do this by recursing down TREE to the interval in question, and |
849 | deleting the appropriate amount of text. */ | |
a50699fd JA |
850 | |
851 | static int | |
852 | interval_deletion_adjustment (tree, from, amount) | |
853 | register INTERVAL tree; | |
854 | register int from, amount; | |
855 | { | |
856 | register int relative_position = from; | |
857 | ||
858 | if (NULL_INTERVAL_P (tree)) | |
859 | return 0; | |
860 | ||
861 | /* Left branch */ | |
862 | if (relative_position <= LEFT_TOTAL_LENGTH (tree)) | |
863 | { | |
864 | int subtract = interval_deletion_adjustment (tree->left, | |
865 | relative_position, | |
866 | amount); | |
867 | tree->total_length -= subtract; | |
868 | return subtract; | |
869 | } | |
870 | /* Right branch */ | |
871 | else if (relative_position > (TOTAL_LENGTH (tree) | |
872 | - RIGHT_TOTAL_LENGTH (tree))) | |
873 | { | |
874 | int subtract; | |
875 | ||
876 | relative_position -= (tree->total_length | |
877 | - RIGHT_TOTAL_LENGTH (tree)); | |
878 | subtract = interval_deletion_adjustment (tree->right, | |
879 | relative_position, | |
880 | amount); | |
881 | tree->total_length -= subtract; | |
882 | return subtract; | |
883 | } | |
884 | /* Here -- this node */ | |
885 | else | |
886 | { | |
887 | /* If this is a zero-length, marker interval, then | |
888 | we must skip it. */ | |
889 | ||
890 | if (relative_position == LEFT_TOTAL_LENGTH (tree) + 1) | |
891 | { | |
892 | /* This means we're deleting from the beginning of this interval. */ | |
893 | register int my_amount = LENGTH (tree); | |
894 | ||
895 | if (amount < my_amount) | |
896 | { | |
897 | tree->total_length -= amount; | |
898 | return amount; | |
899 | } | |
900 | else | |
901 | { | |
902 | tree->total_length -= my_amount; | |
903 | if (LENGTH (tree) != 0) | |
904 | abort (); /* Paranoia */ | |
905 | ||
906 | delete_interval (tree); | |
907 | return my_amount; | |
908 | } | |
909 | } | |
910 | else /* Deleting starting in the middle. */ | |
911 | { | |
912 | register int my_amount = ((tree->total_length | |
913 | - RIGHT_TOTAL_LENGTH (tree)) | |
914 | - relative_position + 1); | |
915 | ||
916 | if (amount <= my_amount) | |
917 | { | |
918 | tree->total_length -= amount; | |
919 | return amount; | |
920 | } | |
921 | else | |
922 | { | |
923 | tree->total_length -= my_amount; | |
924 | return my_amount; | |
925 | } | |
926 | } | |
927 | } | |
928 | ||
1d1d7ba0 | 929 | /* Never reach here */ |
a50699fd JA |
930 | abort (); |
931 | } | |
932 | ||
1d1d7ba0 JA |
933 | /* Effect the adjustments neccessary to the interval tree of BUFFER |
934 | to correspond to the deletion of LENGTH characters from that buffer | |
935 | text. The deletion is effected at position START (relative to the | |
936 | buffer). */ | |
937 | ||
a50699fd JA |
938 | static void |
939 | adjust_intervals_for_deletion (buffer, start, length) | |
940 | struct buffer *buffer; | |
941 | int start, length; | |
942 | { | |
943 | register int left_to_delete = length; | |
944 | register INTERVAL tree = buffer->intervals; | |
945 | register int deleted; | |
946 | ||
947 | if (NULL_INTERVAL_P (tree)) | |
948 | return; | |
949 | ||
950 | if (length == TOTAL_LENGTH (tree)) | |
951 | { | |
952 | buffer->intervals = NULL_INTERVAL; | |
953 | return; | |
954 | } | |
955 | ||
956 | if (ONLY_INTERVAL_P (tree)) | |
957 | { | |
958 | tree->total_length -= length; | |
959 | return; | |
960 | } | |
961 | ||
962 | if (start > TOTAL_LENGTH (tree)) | |
963 | start = TOTAL_LENGTH (tree); | |
964 | while (left_to_delete > 0) | |
965 | { | |
966 | left_to_delete -= interval_deletion_adjustment (tree, start, | |
967 | left_to_delete); | |
968 | tree = buffer->intervals; | |
969 | if (left_to_delete == tree->total_length) | |
970 | { | |
971 | buffer->intervals = NULL_INTERVAL; | |
972 | return; | |
973 | } | |
974 | } | |
975 | } | |
976 | \f | |
1d1d7ba0 JA |
977 | /* Make the adjustments neccessary to the interval tree of BUFFER to |
978 | represent an addition or deletion of LENGTH characters starting | |
979 | at position START. Addition or deletion is indicated by the sign | |
980 | of LENGTH. */ | |
a50699fd JA |
981 | |
982 | INLINE void | |
983 | offset_intervals (buffer, start, length) | |
984 | struct buffer *buffer; | |
985 | int start, length; | |
986 | { | |
987 | if (NULL_INTERVAL_P (buffer->intervals) || length == 0) | |
988 | return; | |
989 | ||
990 | if (length > 0) | |
991 | adjust_intervals_for_insertion (buffer->intervals, start, length); | |
992 | else | |
993 | adjust_intervals_for_deletion (buffer, start, -length); | |
994 | } | |
995 | ||
1d1d7ba0 JA |
996 | /* Make an exact copy of interval tree SOURCE which descends from |
997 | PARENT. This is done by recursing through SOURCE, copying | |
998 | the current interval and its properties, and then adjusting | |
999 | the pointers of the copy. */ | |
1000 | ||
a50699fd JA |
1001 | static INTERVAL |
1002 | reproduce_tree (source, parent) | |
1003 | INTERVAL source, parent; | |
1004 | { | |
1005 | register INTERVAL t = make_interval (); | |
1006 | ||
1007 | bcopy (source, t, INTERVAL_SIZE); | |
1008 | copy_properties (source, t); | |
1009 | t->parent = parent; | |
1010 | if (! NULL_LEFT_CHILD (source)) | |
1011 | t->left = reproduce_tree (source->left, t); | |
1012 | if (! NULL_RIGHT_CHILD (source)) | |
1013 | t->right = reproduce_tree (source->right, t); | |
1014 | ||
1015 | return t; | |
1016 | } | |
1017 | ||
1d1d7ba0 JA |
1018 | /* Make a new interval of length LENGTH starting at START in the |
1019 | group of intervals INTERVALS, which is actually an interval tree. | |
1020 | Returns the new interval. | |
1021 | ||
1022 | Generate an error if the new positions would overlap an existing | |
1023 | interval. */ | |
1024 | ||
a50699fd JA |
1025 | static INTERVAL |
1026 | make_new_interval (intervals, start, length) | |
1027 | INTERVAL intervals; | |
1028 | int start, length; | |
1029 | { | |
1030 | INTERVAL slot; | |
1031 | ||
1032 | slot = find_interval (intervals, start); | |
1033 | if (start + length > slot->position + LENGTH (slot)) | |
1034 | error ("Interval would overlap"); | |
1035 | ||
1036 | if (start == slot->position && length == LENGTH (slot)) | |
1037 | return slot; | |
1038 | ||
1039 | if (slot->position == start) | |
1040 | { | |
1041 | /* New right node. */ | |
1042 | split_interval_right (slot, length + 1); | |
1043 | return slot; | |
1044 | } | |
1045 | ||
1046 | if (slot->position + LENGTH (slot) == start + length) | |
1047 | { | |
1048 | /* New left node. */ | |
1049 | split_interval_left (slot, LENGTH (slot) - length + 1); | |
1050 | return slot; | |
1051 | } | |
1052 | ||
1053 | /* Convert interval SLOT into three intervals. */ | |
1054 | split_interval_left (slot, start - slot->position + 1); | |
1055 | split_interval_right (slot, length + 1); | |
1056 | return slot; | |
1057 | } | |
1058 | ||
1059 | void | |
1060 | map_intervals (source, destination, position) | |
1061 | INTERVAL source, destination; | |
1062 | int position; | |
1063 | { | |
1064 | register INTERVAL i, t; | |
1065 | ||
1066 | if (NULL_INTERVAL_P (source)) | |
1067 | return; | |
1068 | i = find_interval (destination, position); | |
1069 | if (NULL_INTERVAL_P (i)) | |
1070 | return; | |
1071 | ||
1072 | t = find_interval (source, 1); | |
1073 | while (! NULL_INTERVAL_P (t)) | |
1074 | { | |
1075 | i = make_new_interval (destination, position, LENGTH (t)); | |
1076 | position += LENGTH (t); | |
1077 | copy_properties (t, i); | |
1078 | t = next_interval (t); | |
1079 | } | |
1080 | } | |
1081 | ||
1082 | /* Insert the intervals of NEW_TREE into BUFFER at POSITION. | |
1083 | ||
1084 | This is used in insdel.c when inserting Lisp_Strings into | |
1085 | the buffer. The text corresponding to NEW_TREE is already in | |
1086 | the buffer when this is called. The intervals of new tree are | |
1087 | those belonging to the string being inserted; a copy is not made. | |
1088 | ||
1089 | If the inserted text had no intervals associated, this function | |
1090 | simply returns -- offset_intervals should handle placing the | |
90ba40fc | 1091 | text in the correct interval, depending on the sticky bits. |
a50699fd JA |
1092 | |
1093 | If the inserted text had properties (intervals), then there are two | |
1094 | cases -- either insertion happened in the middle of some interval, | |
1095 | or between two intervals. | |
1096 | ||
1097 | If the text goes into the middle of an interval, then new | |
1098 | intervals are created in the middle with only the properties of | |
1099 | the new text, *unless* the macro MERGE_INSERTIONS is true, in | |
1100 | which case the new text has the union of its properties and those | |
1101 | of the text into which it was inserted. | |
1102 | ||
1103 | If the text goes between two intervals, then if neither interval | |
90ba40fc JA |
1104 | had its appropriate sticky property set (front_sticky, rear_sticky), |
1105 | the new text has only its properties. If one of the sticky properties | |
a50699fd JA |
1106 | is set, then the new text "sticks" to that region and its properties |
1107 | depend on merging as above. If both the preceding and succeding | |
90ba40fc JA |
1108 | intervals to the new text are "sticky", then the new text retains |
1109 | only its properties, as if neither sticky property were set. Perhaps | |
a50699fd JA |
1110 | we should consider merging all three sets of properties onto the new |
1111 | text... */ | |
1112 | ||
1113 | void | |
1114 | graft_intervals_into_buffer (new_tree, position, b) | |
1115 | INTERVAL new_tree; | |
1116 | int position; | |
1117 | struct buffer *b; | |
1118 | { | |
1119 | register INTERVAL under, over, this; | |
1120 | register INTERVAL tree = b->intervals; | |
1121 | ||
1122 | /* If the new text has no properties, it becomes part of whatever | |
1123 | interval it was inserted into. */ | |
1124 | if (NULL_INTERVAL_P (new_tree)) | |
1125 | return; | |
1126 | ||
1127 | /* Paranoia -- the text has already been added, so this buffer | |
1128 | should be of non-zero length. */ | |
1129 | if (TOTAL_LENGTH (tree) == 0) | |
1130 | abort (); | |
1131 | ||
1132 | if (NULL_INTERVAL_P (tree)) | |
1133 | { | |
1134 | /* The inserted text constitutes the whole buffer, so | |
1135 | simply copy over the interval structure. */ | |
1136 | if (BUF_Z (b) == TOTAL_LENGTH (new_tree)) | |
1137 | { | |
1138 | b->intervals = reproduce_tree (new_tree, tree->parent); | |
1139 | /* Explicitly free the old tree here. */ | |
1140 | ||
1141 | return; | |
1142 | } | |
1143 | ||
1144 | /* Create an interval tree in which to place a copy | |
1145 | of the intervals of the inserted string. */ | |
1146 | { | |
1147 | Lisp_Object buffer; | |
1148 | XSET (buffer, Lisp_Buffer, b); | |
1149 | create_root_interval (buffer); | |
1150 | } | |
1151 | } | |
1152 | else | |
1153 | if (TOTAL_LENGTH (tree) == TOTAL_LENGTH (new_tree)) | |
1154 | ||
1155 | /* If the buffer contains only the new string, but | |
1156 | there was already some interval tree there, then it may be | |
1157 | some zero length intervals. Eventually, do something clever | |
1158 | about inserting properly. For now, just waste the old intervals. */ | |
1159 | { | |
1160 | b->intervals = reproduce_tree (new_tree, tree->parent); | |
1161 | /* Explicitly free the old tree here. */ | |
1162 | ||
1163 | return; | |
1164 | } | |
1165 | ||
1166 | this = under = find_interval (tree, position); | |
1167 | if (NULL_INTERVAL_P (under)) /* Paranoia */ | |
1168 | abort (); | |
1169 | over = find_interval (new_tree, 1); | |
1170 | ||
1171 | /* Insertion between intervals */ | |
1172 | if (position == under->position) | |
1173 | { | |
1174 | /* First interval -- none precede it. */ | |
1175 | if (position == 1) | |
1176 | { | |
90ba40fc | 1177 | if (! FRONT_STICKY (under)) |
a50699fd JA |
1178 | /* The inserted string keeps its own properties. */ |
1179 | while (! NULL_INTERVAL_P (over)) | |
1180 | { | |
1181 | position = LENGTH (over) + 1; | |
1182 | this = split_interval_left (this, position); | |
1183 | copy_properties (over, this); | |
1184 | over = next_interval (over); | |
1185 | } | |
1186 | else | |
1187 | /* This string sticks to under */ | |
1188 | while (! NULL_INTERVAL_P (over)) | |
1189 | { | |
1190 | position = LENGTH (over) + 1; | |
1191 | this = split_interval_left (this, position); | |
1192 | copy_properties (under, this); | |
1193 | if (MERGE_INSERTIONS (under)) | |
1194 | merge_properties (over, this); | |
1195 | over = next_interval (over); | |
1196 | } | |
1197 | } | |
1198 | else | |
1199 | { | |
1200 | INTERVAL prev = previous_interval (under); | |
1201 | if (NULL_INTERVAL_P (prev)) | |
1202 | abort (); | |
1203 | ||
90ba40fc | 1204 | if (END_STICKY (prev)) |
a50699fd | 1205 | { |
90ba40fc JA |
1206 | if (FRONT_STICKY (under)) |
1207 | /* The intervals go inbetween as the two sticky | |
a50699fd JA |
1208 | properties cancel each other. Should we change |
1209 | this policy? */ | |
1210 | while (! NULL_INTERVAL_P (over)) | |
1211 | { | |
1212 | position = LENGTH (over) + 1; | |
1213 | this = split_interval_left (this, position); | |
1214 | copy_properties (over, this); | |
1215 | over = next_interval (over); | |
1216 | } | |
1217 | else | |
1218 | /* The intervals stick to prev */ | |
1219 | while (! NULL_INTERVAL_P (over)) | |
1220 | { | |
1221 | position = LENGTH (over) + 1; | |
1222 | this = split_interval_left (this, position); | |
1223 | copy_properties (prev, this); | |
1224 | if (MERGE_INSERTIONS (prev)) | |
1225 | merge_properties (over, this); | |
1226 | over = next_interval (over); | |
1227 | } | |
1228 | } | |
1229 | else | |
1230 | { | |
90ba40fc | 1231 | if (FRONT_STICKY (under)) |
a50699fd JA |
1232 | /* The intervals stick to under */ |
1233 | while (! NULL_INTERVAL_P (over)) | |
1234 | { | |
1235 | position = LENGTH (over) + 1; | |
1236 | this = split_interval_left (this, position); | |
1237 | copy_properties (under, this); | |
1238 | if (MERGE_INSERTIONS (under)) | |
1239 | merge_properties (over, this); | |
1240 | over = next_interval (over); | |
1241 | } | |
1242 | else | |
1243 | /* The intervals go inbetween */ | |
1244 | while (! NULL_INTERVAL_P (over)) | |
1245 | { | |
1246 | position = LENGTH (over) + 1; | |
1247 | this = split_interval_left (this, position); | |
1248 | copy_properties (over, this); | |
1249 | over = next_interval (over); | |
1250 | } | |
1251 | } | |
1252 | } | |
1253 | ||
1254 | b->intervals = balance_intervals (b->intervals); | |
1255 | return; | |
1256 | } | |
1257 | ||
1258 | /* Here for insertion in the middle of an interval. */ | |
1259 | ||
1260 | if (TOTAL_LENGTH (new_tree) < LENGTH (this)) | |
1261 | { | |
1262 | INTERVAL end_unchanged | |
1263 | = split_interval_right (this, TOTAL_LENGTH (new_tree) + 1); | |
1264 | copy_properties (under, end_unchanged); | |
1265 | } | |
1266 | ||
1267 | position = position - tree->position + 1; | |
1268 | while (! NULL_INTERVAL_P (over)) | |
1269 | { | |
1270 | this = split_interval_right (under, position); | |
1271 | copy_properties (over, this); | |
1272 | if (MERGE_INSERTIONS (under)) | |
1273 | merge_properties (under, this); | |
1274 | ||
1275 | position = LENGTH (over) + 1; | |
1276 | over = next_interval (over); | |
1277 | } | |
1278 | ||
1279 | b->intervals = balance_intervals (b->intervals); | |
1280 | return; | |
1281 | } | |
1282 | ||
1283 | /* Intervals can have properties which are hooks to call. Look for | |
1284 | the property HOOK on interval I, and if found, call its value as | |
1285 | a function.*/ | |
1286 | ||
1287 | void | |
1288 | run_hooks (i, hook) | |
1289 | INTERVAL i; | |
1290 | Lisp_Object hook; | |
1291 | { | |
1292 | register Lisp_Object tail = i->plist; | |
1293 | register Lisp_Object sym, val; | |
1294 | ||
1295 | while (! NILP (tail)) | |
1296 | { | |
1297 | sym = Fcar (tail); | |
1298 | if (EQ (sym, hook)) | |
1299 | { | |
1300 | Lisp_Object begin, end; | |
1301 | XFASTINT (begin) = i->position; | |
1302 | XFASTINT (end) = i->position + LENGTH (i) - 1; | |
1303 | val = Fcar (Fcdr (tail)); | |
1304 | call2 (val, begin, end); | |
1305 | return; | |
1306 | } | |
1307 | ||
1308 | tail = Fcdr (Fcdr (tail)); | |
1309 | } | |
1310 | } | |
1311 | ||
1312 | /* Set point in BUFFER to POSITION. If the target position is in | |
1313 | an invisible interval which is not displayed with a special glyph, | |
1314 | skip intervals until we find one. Point may be at the first | |
1315 | position of an invisible interval, if it is displayed with a | |
1316 | special glyph. | |
1317 | ||
1318 | This is the only place `PT' is an lvalue in all of emacs. */ | |
1319 | ||
1320 | void | |
1321 | set_point (position, buffer) | |
1322 | register int position; | |
1323 | register struct buffer *buffer; | |
1324 | { | |
1325 | register INTERVAL to, from, target; | |
1326 | register int iposition = position; | |
1327 | int buffer_point; | |
1328 | register Lisp_Object obj; | |
1329 | int backwards = (position < BUF_PT (buffer)) ? 1 : 0; | |
1330 | ||
1331 | if (position == buffer->text.pt) | |
1332 | return; | |
1333 | ||
1334 | if (NULL_INTERVAL_P (buffer->intervals)) | |
1335 | { | |
1336 | buffer->text.pt = position; | |
1337 | return; | |
1338 | } | |
1339 | ||
1340 | /* Perhaps we should just change `position' to the limit. */ | |
1341 | if (position > BUF_Z (buffer) || position < BUF_BEG (buffer)) | |
1342 | abort (); | |
1343 | ||
1344 | /* Position Z is really one past the last char in the buffer. */ | |
1345 | if (position == BUF_Z (buffer)) | |
1346 | iposition = position - 1; | |
1347 | ||
1348 | to = find_interval (buffer->intervals, iposition); | |
1349 | buffer_point =(BUF_PT (buffer) == BUF_Z (buffer) | |
1350 | ? BUF_Z (buffer) - 1 | |
1351 | : BUF_PT (buffer)); | |
1352 | from = find_interval (buffer->intervals, buffer_point); | |
1353 | if (NULL_INTERVAL_P (to) || NULL_INTERVAL_P (from)) | |
1354 | abort (); /* Paranoia */ | |
1355 | ||
1356 | /* Moving within an interval */ | |
1357 | if (to == from && INTERVAL_VISIBLE_P (to)) | |
1358 | { | |
1359 | buffer->text.pt = position; | |
1360 | return; | |
1361 | } | |
1362 | ||
1363 | /* Here for the case of moving into another interval. */ | |
1364 | ||
1365 | target = to; | |
1366 | while (! INTERVAL_VISIBLE_P (to) && ! DISPLAY_INVISIBLE_GLYPH (to) | |
1367 | && ! NULL_INTERVAL_P (to)) | |
1368 | to = (backwards ? previous_interval (to) : next_interval (to)); | |
1369 | if (NULL_INTERVAL_P (to)) | |
1370 | return; | |
1371 | ||
1372 | /* Here we know we are actually moving to another interval. */ | |
1373 | if (INTERVAL_VISIBLE_P (to)) | |
1374 | { | |
1375 | /* If we skipped some intervals, go to the closest point | |
1376 | in the interval we've stopped at. */ | |
1377 | if (to != target) | |
1378 | buffer->text.pt = (backwards | |
1379 | ? to->position + LENGTH (to) - 1 | |
1380 | : to->position); | |
1381 | else | |
1382 | buffer->text.pt = position; | |
1383 | } | |
1384 | else | |
1385 | buffer->text.pt = to->position; | |
1386 | ||
1387 | /* We should run point-left and point-entered hooks here, iff the | |
1388 | two intervals are not equivalent. */ | |
1389 | } | |
1390 | ||
1391 | /* Check for read-only intervals. Call the modification hooks if any. | |
1392 | Check for the range START up to (but not including) TO. | |
1393 | ||
1394 | First all intervals of the region are checked that they are | |
1395 | modifiable, then all the modification hooks are called in | |
1396 | lexicographic order. */ | |
1397 | ||
1398 | void | |
1399 | verify_interval_modification (buf, start, end) | |
1400 | struct buffer *buf; | |
1401 | int start, end; | |
1402 | { | |
1403 | register INTERVAL intervals = buf->intervals; | |
1404 | register INTERVAL i; | |
1405 | register Lisp_Object hooks = Qnil; | |
1406 | ||
1407 | if (NULL_INTERVAL_P (intervals)) | |
1408 | return; | |
1409 | ||
1410 | if (start > end) | |
1411 | { | |
1412 | int temp = start; | |
1413 | start = end; | |
1414 | end = temp; | |
1415 | } | |
1416 | ||
1417 | if (start == BUF_Z (buf)) | |
1418 | { | |
1419 | if (BUF_Z (buf) == 1) | |
1420 | abort (); | |
1421 | ||
1422 | i = find_interval (intervals, start - 1); | |
90ba40fc | 1423 | if (! END_STICKY_P (i)) |
a50699fd JA |
1424 | return; |
1425 | } | |
1426 | else | |
1427 | i = find_interval (intervals, start); | |
1428 | ||
1429 | do | |
1430 | { | |
1431 | register Lisp_Object mod_hook; | |
1432 | if (! INTERVAL_WRITABLE_P (i)) | |
1433 | error ("Attempt to write in a protected interval"); | |
1434 | mod_hook = Fget (Qmodification, i->plist); | |
1435 | if (! EQ (mod_hook, Qnil)) | |
1436 | hooks = Fcons (mod_hook, hooks); | |
1437 | i = next_interval (i); | |
1438 | } | |
1439 | while (! NULL_INTERVAL_P (i) && i->position <= end); | |
1440 | ||
1441 | hooks = Fnreverse (hooks); | |
1442 | while (! EQ (hooks, Qnil)) | |
1443 | call2 (Fcar (hooks), i->position, i->position + LENGTH (i) - 1); | |
1444 | } | |
1445 | ||
1446 | /* Balance an interval node if the amount of text in its left and right | |
1447 | subtrees differs by more than the percentage specified by | |
1448 | `interval-balance-threshold'. */ | |
1449 | ||
1450 | static INTERVAL | |
1451 | balance_an_interval (i) | |
1452 | INTERVAL i; | |
1453 | { | |
1454 | register int total_children_size = (LEFT_TOTAL_LENGTH (i) | |
1455 | + RIGHT_TOTAL_LENGTH (i)); | |
1456 | register int threshold = (XFASTINT (interval_balance_threshold) | |
1457 | * (total_children_size / 100)); | |
1458 | ||
1459 | if (LEFT_TOTAL_LENGTH (i) > RIGHT_TOTAL_LENGTH (i) | |
1460 | && (LEFT_TOTAL_LENGTH (i) - RIGHT_TOTAL_LENGTH (i)) > threshold) | |
1461 | return rotate_right (i); | |
1462 | ||
1463 | if (LEFT_TOTAL_LENGTH (i) > RIGHT_TOTAL_LENGTH (i) | |
1464 | && (LEFT_TOTAL_LENGTH (i) - RIGHT_TOTAL_LENGTH (i)) > threshold) | |
1465 | return rotate_right (i); | |
1466 | ||
1467 | #if 0 | |
1468 | if (LEFT_TOTAL_LENGTH (i) > | |
1469 | (RIGHT_TOTAL_LENGTH (i) + XINT (interval_balance_threshold))) | |
1470 | return rotate_right (i); | |
1471 | ||
1472 | if (RIGHT_TOTAL_LENGTH (i) > | |
1473 | (LEFT_TOTAL_LENGTH (i) + XINT (interval_balance_threshold))) | |
1474 | return rotate_left (i); | |
1475 | #endif | |
1476 | ||
1477 | return i; | |
1478 | } | |
1479 | ||
1480 | /* Balance the interval tree TREE. Balancing is by weight | |
1481 | (the amount of text). */ | |
1482 | ||
1483 | INTERVAL | |
1484 | balance_intervals (tree) | |
1485 | register INTERVAL tree; | |
1486 | { | |
1487 | register INTERVAL new_tree; | |
1488 | ||
1489 | if (NULL_INTERVAL_P (tree)) | |
1490 | return NULL_INTERVAL; | |
1491 | ||
1492 | new_tree = tree; | |
1493 | do | |
1494 | { | |
1495 | tree = new_tree; | |
1496 | new_tree = balance_an_interval (new_tree); | |
1497 | } | |
1498 | while (new_tree != tree); | |
1499 | ||
1500 | return new_tree; | |
1501 | } | |
1502 | ||
1503 | /* Produce an interval tree reflecting the interval structure in | |
1504 | TREE from START to START + LENGTH. */ | |
1505 | ||
1506 | static INTERVAL | |
1507 | copy_intervals (tree, start, length) | |
1508 | INTERVAL tree; | |
1509 | int start, length; | |
1510 | { | |
1511 | register INTERVAL i, new, t; | |
1512 | register int got; | |
1513 | ||
1514 | if (NULL_INTERVAL_P (tree) || length <= 0) | |
1515 | return NULL_INTERVAL; | |
1516 | ||
1517 | i = find_interval (tree, start); | |
1518 | if (NULL_INTERVAL_P (i) || LENGTH (i) == 0) | |
1519 | abort (); | |
1520 | ||
1521 | /* If there is only one interval and it's the default, return nil. */ | |
1522 | if ((start - i->position + 1 + length) < LENGTH (i) | |
1523 | && DEFAULT_INTERVAL_P (i)) | |
1524 | return NULL_INTERVAL; | |
1525 | ||
1526 | new = make_interval (); | |
1527 | new->position = 1; | |
1528 | got = (LENGTH (i) - (start - i->position)); | |
1529 | new->total_length = got; | |
1530 | copy_properties (i, new); | |
1531 | ||
1532 | t = new; | |
1533 | while (got < length) | |
1534 | { | |
1535 | i = next_interval (i); | |
1536 | t->right = make_interval (); | |
1537 | t->right->parent = t; | |
1538 | t->right->position = t->position + got - 1; | |
1539 | ||
1540 | t = t->right; | |
1541 | t->total_length = length - got; | |
1542 | copy_properties (i, t); | |
1543 | got += LENGTH (i); | |
1544 | } | |
1545 | ||
1546 | if (got > length) | |
1547 | t->total_length -= (got - length); | |
1548 | ||
1549 | return balance_intervals (new); | |
1550 | } | |
1551 | ||
1552 | /* Give buffer SINK the properties of buffer SOURCE from POSITION | |
1553 | to END. The properties are attached to SINK starting at position AT. | |
1554 | ||
1555 | No range checking is done. */ | |
1556 | ||
1557 | void | |
1558 | insert_interval_copy (source, position, end, sink, at) | |
1559 | struct buffer *source, *sink; | |
1560 | register int position, end, at; | |
1561 | { | |
1562 | INTERVAL interval_copy = copy_intervals (source->intervals, | |
1563 | position, end - position); | |
1564 | graft_intervals_into_buffer (interval_copy, at, sink); | |
1565 | } | |
1566 | ||
1567 | /* Give STRING the properties of BUFFER from POSITION to LENGTH. */ | |
1568 | ||
1569 | void | |
1570 | copy_intervals_to_string (string, buffer, position, length) | |
1571 | Lisp_Object string, buffer; | |
1572 | int position, length; | |
1573 | { | |
1574 | INTERVAL interval_copy = copy_intervals (XBUFFER (buffer)->intervals, | |
1575 | position, length); | |
1576 | if (NULL_INTERVAL_P (interval_copy)) | |
1577 | return; | |
1578 | ||
1579 | interval_copy->parent = (INTERVAL) string; | |
1580 | XSTRING (string)->intervals = interval_copy; | |
1581 | } | |
1582 | ||
1583 | INTERVAL | |
1584 | make_string_interval (string, start, length) | |
1585 | struct Lisp_String *string; | |
1586 | int start, length; | |
1587 | { | |
1588 | if (start < 1 || start > string->size) | |
1589 | error ("Interval index out of range"); | |
1590 | if (length < 1 || length > string->size - start + 1) | |
1591 | error ("Interval won't fit"); | |
1592 | ||
1593 | if (length == 0) | |
1594 | return NULL_INTERVAL; | |
1595 | ||
1596 | return make_new_interval (string->intervals, start, length); | |
1597 | } | |
1598 | ||
1599 | /* Create an interval of length LENGTH in buffer BUF at position START. */ | |
1600 | ||
1601 | INTERVAL | |
1602 | make_buffer_interval (buf, start, length) | |
1603 | struct buffer *buf; | |
1604 | int start, length; | |
1605 | { | |
1606 | if (start < BUF_BEG (buf) || start > BUF_Z (buf)) | |
1607 | error ("Interval index out of range"); | |
1608 | if (length < 1 || length > BUF_Z (buf) - start) | |
1609 | error ("Interval won't fit"); | |
1610 | ||
1611 | if (length == 0) | |
1612 | return NULL_INTERVAL; | |
1613 | ||
1614 | return make_new_interval (buf->intervals, start, length); | |
1615 | } |