intervals.c 72.2 KB
Newer Older
Joseph Arceneaux's avatar
Joseph Arceneaux committed
1
/* Code for doing intervals.
2
   Copyright (C) 1993-1995, 1997-1998, 2001-2011  Free Software Foundation, Inc.
Joseph Arceneaux's avatar
Joseph Arceneaux committed
3 4 5

This file is part of GNU Emacs.

6
GNU Emacs is free software: you can redistribute it and/or modify
Joseph Arceneaux's avatar
Joseph Arceneaux committed
7
it under the terms of the GNU General Public License as published by
8 9
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Joseph Arceneaux's avatar
Joseph Arceneaux committed
10 11 12 13 14 15 16

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
17
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39


/* NOTES:

   Have to ensure that we can't put symbol nil on a plist, or some
   functions may work incorrectly.

   An idea:  Have the owner of the tree keep count of splits and/or
   insertion lengths (in intervals), and balance after every N.

   Need to call *_left_hook when buffer is killed.

   Scan for zero-length, or 0-length to see notes about handling
   zero length interval-markers.

   There are comments around about freeing intervals.  It might be
   faster to explicitly free them (put them on the free list) than
   to GC them.

*/


40
#include <config.h>
41
#include <setjmp.h>
42
#include <intprops.h>
Joseph Arceneaux's avatar
Joseph Arceneaux committed
43 44 45
#include "lisp.h"
#include "intervals.h"
#include "buffer.h"
Richard M. Stallman's avatar
Richard M. Stallman committed
46
#include "puresize.h"
Karl Heuer's avatar
Karl Heuer committed
47
#include "keyboard.h"
Stefan Monnier's avatar
Stefan Monnier committed
48
#include "keymap.h"
Joseph Arceneaux's avatar
Joseph Arceneaux committed
49

50 51 52 53 54
/* Test for membership, allowing for t (actually any non-cons) to mean the
   universal set.  */

#define TMEM(sym, set) (CONSP (set) ? ! NILP (Fmemq (sym, set)) : ! NILP (set))

55 56
static Lisp_Object merge_properties_sticky (Lisp_Object, Lisp_Object);
static INTERVAL merge_interval_right (INTERVAL);
57 58
static INTERVAL reproduce_tree (INTERVAL, INTERVAL);
static INTERVAL reproduce_tree_obj (INTERVAL, Lisp_Object);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
59

60
/* Utility functions for intervals.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
61 62


63
/* Create the root interval of some object, a buffer or string.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
64 65

INTERVAL
66
create_root_interval (Lisp_Object parent)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
67
{
Richard M. Stallman's avatar
Richard M. Stallman committed
68 69 70 71 72
  INTERVAL new;

  CHECK_IMPURE (parent);

  new = make_interval ();
Joseph Arceneaux's avatar
Joseph Arceneaux committed
73

74
  if (BUFFERP (parent))
Joseph Arceneaux's avatar
Joseph Arceneaux committed
75
    {
76 77
      new->total_length = (BUF_Z (XBUFFER (parent))
			   - BUF_BEG (XBUFFER (parent)));
78
      CHECK_TOTAL_LENGTH (new);
79
      BUF_INTERVALS (XBUFFER (parent)) = new;
80
      new->position = BEG;
Joseph Arceneaux's avatar
Joseph Arceneaux committed
81
    }
82
  else if (STRINGP (parent))
Joseph Arceneaux's avatar
Joseph Arceneaux committed
83
    {
84
      new->total_length = SCHARS (parent);
85
      CHECK_TOTAL_LENGTH (new);
86
      STRING_SET_INTERVALS (parent, new);
87
      new->position = 0;
Joseph Arceneaux's avatar
Joseph Arceneaux committed
88 89
    }

90
  SET_INTERVAL_OBJECT (new, parent);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
91 92 93 94 95 96 97

  return new;
}

/* Make the interval TARGET have exactly the properties of SOURCE */

void
98
copy_properties (register INTERVAL source, register INTERVAL target)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
99 100 101 102 103 104 105 106 107
{
  if (DEFAULT_INTERVAL_P (source) && DEFAULT_INTERVAL_P (target))
    return;

  COPY_INTERVAL_CACHE (source, target);
  target->plist = Fcopy_sequence (source->plist);
}

/* Merge the properties of interval SOURCE into the properties
108 109
   of interval TARGET.  That is to say, each property in SOURCE
   is added to TARGET if TARGET has no such property as yet.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
110 111

static void
112
merge_properties (register INTERVAL source, register INTERVAL target)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
113 114 115 116 117 118 119 120 121
{
  register Lisp_Object o, sym, val;

  if (DEFAULT_INTERVAL_P (source) && DEFAULT_INTERVAL_P (target))
    return;

  MERGE_INTERVAL_CACHE (source, target);

  o = source->plist;
122
  while (CONSP (o))
Joseph Arceneaux's avatar
Joseph Arceneaux committed
123
    {
124
      sym = XCAR (o);
125 126 127 128 129 130 131 132 133 134 135
      o = XCDR (o);
      CHECK_CONS (o);

      val = target->plist;
      while (CONSP (val) && !EQ (XCAR (val), sym))
	{
	  val = XCDR (val);
	  if (!CONSP (val))
	    break;
	  val = XCDR (val);
	}
Joseph Arceneaux's avatar
Joseph Arceneaux committed
136 137 138

      if (NILP (val))
	{
139
	  val = XCAR (o);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
140 141
	  target->plist = Fcons (sym, Fcons (val, target->plist));
	}
142
      o = XCDR (o);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
143 144 145 146
    }
}

/* Return 1 if the two intervals have the same properties,
147
   0 otherwise.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
148 149

int
150
intervals_equal (INTERVAL i0, INTERVAL i1)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
151
{
152 153
  register Lisp_Object i0_cdr, i0_sym;
  register Lisp_Object i1_cdr, i1_val;
Joseph Arceneaux's avatar
Joseph Arceneaux committed
154 155 156 157

  if (DEFAULT_INTERVAL_P (i0) && DEFAULT_INTERVAL_P (i1))
    return 1;

158 159 160
  if (DEFAULT_INTERVAL_P (i0) || DEFAULT_INTERVAL_P (i1))
    return 0;

Joseph Arceneaux's avatar
Joseph Arceneaux committed
161
  i0_cdr = i0->plist;
162 163
  i1_cdr = i1->plist;
  while (CONSP (i0_cdr) && CONSP (i1_cdr))
Joseph Arceneaux's avatar
Joseph Arceneaux committed
164
    {
165
      i0_sym = XCAR (i0_cdr);
166 167 168 169 170 171 172 173 174 175 176
      i0_cdr = XCDR (i0_cdr);
      if (!CONSP (i0_cdr))
	return 0;		/* abort (); */
      i1_val = i1->plist;
      while (CONSP (i1_val) && !EQ (XCAR (i1_val), i0_sym))
	{
	  i1_val = XCDR (i1_val);
	  if (!CONSP (i1_val))
	    return 0;		/* abort (); */
	  i1_val = XCDR (i1_val);
	}
Joseph Arceneaux's avatar
Joseph Arceneaux committed
177

178
      /* i0 has something i1 doesn't.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
179 180 181
      if (EQ (i1_val, Qnil))
	return 0;

182
      /* i0 and i1 both have sym, but it has different values in each.  */
183 184 185
      if (!CONSP (i1_val)
	  || (i1_val = XCDR (i1_val), !CONSP (i1_val))
	  || !EQ (XCAR (i1_val), XCAR (i0_cdr)))
Joseph Arceneaux's avatar
Joseph Arceneaux committed
186 187
	return 0;

188
      i0_cdr = XCDR (i0_cdr);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
189

190 191 192 193 194
      i1_cdr = XCDR (i1_cdr);
      if (!CONSP (i1_cdr))
	return 0;		/* abort (); */
      i1_cdr = XCDR (i1_cdr);
    }
Joseph Arceneaux's avatar
Joseph Arceneaux committed
195

196 197
  /* Lengths of the two plists were equal.  */
  return (NILP (i0_cdr) && NILP (i1_cdr));
Joseph Arceneaux's avatar
Joseph Arceneaux committed
198 199 200
}


201 202 203 204 205
/* Traverse an interval tree TREE, performing FUNCTION on each node.
   No guarantee is made about the order of traversal.
   Pass FUNCTION two args: an interval, and ARG.  */

void
206
traverse_intervals_noorder (INTERVAL tree, void (*function) (INTERVAL, Lisp_Object), Lisp_Object arg)
207 208 209 210 211 212 213 214 215 216 217 218 219 220 221
{
  /* Minimize stack usage.  */
  while (!NULL_INTERVAL_P (tree))
    {
      (*function) (tree, arg);
      if (NULL_INTERVAL_P (tree->right))
	tree = tree->left;
      else
	{
	  traverse_intervals_noorder (tree->left, function, arg);
	  tree = tree->right;
	}
    }
}

Joseph Arceneaux's avatar
Joseph Arceneaux committed
222
/* Traverse an interval tree TREE, performing FUNCTION on each node.
223
   Pass FUNCTION two args: an interval, and ARG.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
224 225

void
226
traverse_intervals (INTERVAL tree, EMACS_INT position,
227
		    void (*function) (INTERVAL, Lisp_Object), Lisp_Object arg)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
228
{
229 230
  while (!NULL_INTERVAL_P (tree))
    {
231
      traverse_intervals (tree->left, position, function, arg);
232 233 234
      position += LEFT_TOTAL_LENGTH (tree);
      tree->position = position;
      (*function) (tree, arg);
235
      position += LENGTH (tree); tree = tree->right;
236
    }
Joseph Arceneaux's avatar
Joseph Arceneaux committed
237 238 239
}

#if 0
240 241 242 243 244

static int icount;
static int idepth;
static int zero_length;

245
/* These functions are temporary, for debugging purposes only.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266

INTERVAL search_interval, found_interval;

void
check_for_interval (i)
     register INTERVAL i;
{
  if (i == search_interval)
    {
      found_interval = i;
      icount++;
    }
}

INTERVAL
search_for_interval (i, tree)
     register INTERVAL i, tree;
{
  icount = 0;
  search_interval = i;
  found_interval = NULL_INTERVAL;
267
  traverse_intervals_noorder (tree, &check_for_interval, Qnil);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288
  return found_interval;
}

static void
inc_interval_count (i)
     INTERVAL i;
{
  icount++;
  if (LENGTH (i) == 0)
    zero_length++;
  if (depth > idepth)
    idepth = depth;
}

int
count_intervals (i)
     register INTERVAL i;
{
  icount = 0;
  idepth = 0;
  zero_length = 0;
289
  traverse_intervals_noorder (i, &inc_interval_count, Qnil);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
290 291 292 293 294 295 296 297 298 299 300

  return icount;
}

static INTERVAL
root_interval (interval)
     INTERVAL interval;
{
  register INTERVAL i = interval;

  while (! ROOT_INTERVAL_P (i))
301
    i = INTERVAL_PARENT (i);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
302 303 304 305 306 307 308 309 310 311 312 313 314 315

  return i;
}
#endif

/* Assuming that a left child exists, perform the following operation:

     A		  B
    / \		 / \
   B       =>       A
  / \		   / \
     c		  c
*/

Paul Eggert's avatar
Paul Eggert committed
316
static inline INTERVAL
317
rotate_right (INTERVAL interval)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
318 319 320
{
  INTERVAL i;
  INTERVAL B = interval->left;
321
  EMACS_INT old_total = interval->total_length;
Joseph Arceneaux's avatar
Joseph Arceneaux committed
322

323
  /* Deal with any Parent of A;  make it point to B.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
324
  if (! ROOT_INTERVAL_P (interval))
325 326
    {
      if (AM_LEFT_CHILD (interval))
327
	INTERVAL_PARENT (interval)->left = B;
328
      else
329
	INTERVAL_PARENT (interval)->right = B;
330
    }
331
  COPY_INTERVAL_PARENT (B, interval);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
332

333 334 335
  /* Make B the parent of A */
  i = B->right;
  B->right = interval;
336
  SET_INTERVAL_PARENT (interval, B);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
337

338
  /* Make A point to c */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
339 340
  interval->left = i;
  if (! NULL_INTERVAL_P (i))
341
    SET_INTERVAL_PARENT (i, interval);
342

343
  /* A's total length is decreased by the length of B and its left child.  */
344
  interval->total_length -= B->total_length - LEFT_TOTAL_LENGTH (interval);
345
  CHECK_TOTAL_LENGTH (interval);
346 347 348

  /* B must have the same total length of A.  */
  B->total_length = old_total;
349
  CHECK_TOTAL_LENGTH (B);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
350 351 352

  return B;
}
353

Joseph Arceneaux's avatar
Joseph Arceneaux committed
354 355
/* Assuming that a right child exists, perform the following operation:

Juanma Barranquero's avatar
Juanma Barranquero committed
356 357
    A               B
   / \	           / \
Joseph Arceneaux's avatar
Joseph Arceneaux committed
358
      B	   =>     A
Juanma Barranquero's avatar
Juanma Barranquero committed
359
     / \         / \
Joseph Arceneaux's avatar
Joseph Arceneaux committed
360 361 362
    c               c
*/

Paul Eggert's avatar
Paul Eggert committed
363
static inline INTERVAL
364
rotate_left (INTERVAL interval)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
365 366 367
{
  INTERVAL i;
  INTERVAL B = interval->right;
368
  EMACS_INT old_total = interval->total_length;
Joseph Arceneaux's avatar
Joseph Arceneaux committed
369

370
  /* Deal with any parent of A;  make it point to B.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
371
  if (! ROOT_INTERVAL_P (interval))
372 373
    {
      if (AM_LEFT_CHILD (interval))
374
	INTERVAL_PARENT (interval)->left = B;
375
      else
376
	INTERVAL_PARENT (interval)->right = B;
377
    }
378
  COPY_INTERVAL_PARENT (B, interval);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
379 380

  /* Make B the parent of A */
381 382
  i = B->left;
  B->left = interval;
383
  SET_INTERVAL_PARENT (interval, B);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
384 385 386 387

  /* Make A point to c */
  interval->right = i;
  if (! NULL_INTERVAL_P (i))
388
    SET_INTERVAL_PARENT (i, interval);
389

390
  /* A's total length is decreased by the length of B and its right child.  */
391
  interval->total_length -= B->total_length - RIGHT_TOTAL_LENGTH (interval);
392
  CHECK_TOTAL_LENGTH (interval);
393 394 395

  /* B must have the same total length of A.  */
  B->total_length = old_total;
396
  CHECK_TOTAL_LENGTH (B);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
397 398 399 400

  return B;
}

401 402 403 404
/* Balance an interval tree with the assumption that the subtrees
   themselves are already balanced.  */

static INTERVAL
405
balance_an_interval (INTERVAL i)
406
{
407
  register EMACS_INT old_diff, new_diff;
408 409 410 411 412 413

  while (1)
    {
      old_diff = LEFT_TOTAL_LENGTH (i) - RIGHT_TOTAL_LENGTH (i);
      if (old_diff > 0)
	{
414
	  /* Since the left child is longer, there must be one.  */
415 416
	  new_diff = i->total_length - i->left->total_length
	    + RIGHT_TOTAL_LENGTH (i->left) - LEFT_TOTAL_LENGTH (i->left);
Eli Zaretskii's avatar
Eli Zaretskii committed
417
	  if (eabs (new_diff) >= old_diff)
418 419 420 421 422 423
	    break;
	  i = rotate_right (i);
	  balance_an_interval (i->right);
	}
      else if (old_diff < 0)
	{
424
	  /* Since the right child is longer, there must be one.  */
425 426
	  new_diff = i->total_length - i->right->total_length
	    + LEFT_TOTAL_LENGTH (i->right) - RIGHT_TOTAL_LENGTH (i->right);
Eli Zaretskii's avatar
Eli Zaretskii committed
427
	  if (eabs (new_diff) >= -old_diff)
428 429 430 431 432 433 434 435 436 437 438 439 440
	    break;
	  i = rotate_left (i);
	  balance_an_interval (i->left);
	}
      else
	break;
    }
  return i;
}

/* Balance INTERVAL, potentially stuffing it back into its parent
   Lisp Object.  */

Paul Eggert's avatar
Paul Eggert committed
441
static inline INTERVAL
442
balance_possible_root_interval (register INTERVAL interval)
443 444
{
  Lisp_Object parent;
445
  int have_parent = 0;
446

447
  if (!INTERVAL_HAS_OBJECT (interval) && !INTERVAL_HAS_PARENT (interval))
448 449
    return interval;

450 451 452 453 454
  if (INTERVAL_HAS_OBJECT (interval))
    {
      have_parent = 1;
      GET_INTERVAL_OBJECT (parent, interval);
    }
455 456
  interval = balance_an_interval (interval);

457 458 459 460 461
  if (have_parent)
    {
      if (BUFFERP (parent))
	BUF_INTERVALS (XBUFFER (parent)) = interval;
      else if (STRINGP (parent))
462
	STRING_SET_INTERVALS (parent, interval);
463
    }
464 465 466 467 468 469 470 471

  return interval;
}

/* Balance the interval tree TREE.  Balancing is by weight
   (the amount of text).  */

static INTERVAL
472
balance_intervals_internal (register INTERVAL tree)
473 474 475
{
  /* Balance within each side.  */
  if (tree->left)
476
    balance_intervals_internal (tree->left);
477
  if (tree->right)
478
    balance_intervals_internal (tree->right);
479 480 481 482 483 484
  return balance_an_interval (tree);
}

/* Advertised interface to balance intervals.  */

INTERVAL
485
balance_intervals (INTERVAL tree)
486 487 488 489 490 491 492
{
  if (tree == NULL_INTERVAL)
    return NULL_INTERVAL;

  return balance_intervals_internal (tree);
}

493 494 495 496
/* Split INTERVAL into two pieces, starting the second piece at
   character position OFFSET (counting from 0), relative to INTERVAL.
   INTERVAL becomes the left-hand piece, and the right-hand piece
   (second, lexicographically) is returned.
Joseph Arceneaux's avatar
Joseph Arceneaux committed
497 498 499 500 501

   The size and position fields of the two intervals are set based upon
   those of the original interval.  The property list of the new interval
   is reset, thus it is up to the caller to do the right thing with the
   result.
Joseph Arceneaux's avatar
Joseph Arceneaux committed
502 503

   Note that this does not change the position of INTERVAL;  if it is a root,
504
   it is still a root after this operation.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
505 506

INTERVAL
507
split_interval_right (INTERVAL interval, EMACS_INT offset)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
508 509
{
  INTERVAL new = make_interval ();
510 511
  EMACS_INT position = interval->position;
  EMACS_INT new_length = LENGTH (interval) - offset;
Joseph Arceneaux's avatar
Joseph Arceneaux committed
512

513
  new->position = position + offset;
514
  SET_INTERVAL_PARENT (new, interval);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
515

516
  if (NULL_RIGHT_CHILD (interval))
Joseph Arceneaux's avatar
Joseph Arceneaux committed
517 518 519
    {
      interval->right = new;
      new->total_length = new_length;
520
      CHECK_TOTAL_LENGTH (new);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
521
    }
522 523 524 525
  else
    {
      /* Insert the new node between INTERVAL and its right child.  */
      new->right = interval->right;
526
      SET_INTERVAL_PARENT (interval->right, new);
527 528
      interval->right = new;
      new->total_length = new_length + new->right->total_length;
529
      CHECK_TOTAL_LENGTH (new);
530 531
      balance_an_interval (new);
    }
Juanma Barranquero's avatar
Juanma Barranquero committed
532

533 534
  balance_possible_root_interval (interval);

Joseph Arceneaux's avatar
Joseph Arceneaux committed
535 536 537
  return new;
}

538 539 540 541
/* Split INTERVAL into two pieces, starting the second piece at
   character position OFFSET (counting from 0), relative to INTERVAL.
   INTERVAL becomes the right-hand piece, and the left-hand piece
   (first, lexicographically) is returned.
Joseph Arceneaux's avatar
Joseph Arceneaux committed
542

Joseph Arceneaux's avatar
Joseph Arceneaux committed
543 544 545 546 547 548
   The size and position fields of the two intervals are set based upon
   those of the original interval.  The property list of the new interval
   is reset, thus it is up to the caller to do the right thing with the
   result.

   Note that this does not change the position of INTERVAL;  if it is a root,
549
   it is still a root after this operation.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
550 551

INTERVAL
552
split_interval_left (INTERVAL interval, EMACS_INT offset)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
553 554
{
  INTERVAL new = make_interval ();
555
  EMACS_INT new_length = offset;
Joseph Arceneaux's avatar
Joseph Arceneaux committed
556 557

  new->position = interval->position;
558
  interval->position = interval->position + offset;
559
  SET_INTERVAL_PARENT (new, interval);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
560 561 562 563 564

  if (NULL_LEFT_CHILD (interval))
    {
      interval->left = new;
      new->total_length = new_length;
565
      CHECK_TOTAL_LENGTH (new);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
566
    }
567 568 569 570
  else
    {
      /* Insert the new node between INTERVAL and its left child.  */
      new->left = interval->left;
571
      SET_INTERVAL_PARENT (new->left, new);
572 573
      interval->left = new;
      new->total_length = new_length + new->left->total_length;
574
      CHECK_TOTAL_LENGTH (new);
575 576
      balance_an_interval (new);
    }
Juanma Barranquero's avatar
Juanma Barranquero committed
577

578
  balance_possible_root_interval (interval);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
579 580 581 582

  return new;
}

583 584 585 586 587 588 589 590
/* Return the proper position for the first character
   described by the interval tree SOURCE.
   This is 1 if the parent is a buffer,
   0 if the parent is a string or if there is no parent.

   Don't use this function on an interval which is the child
   of another interval!  */

591
static int
592
interval_start_pos (INTERVAL source)
593 594 595 596 597 598
{
  Lisp_Object parent;

  if (NULL_INTERVAL_P (source))
    return 0;

599 600
  if (! INTERVAL_HAS_OBJECT (source))
    return 0;
601
  GET_INTERVAL_OBJECT (parent, source);
602 603 604 605 606
  if (BUFFERP (parent))
    return BUF_BEG (XBUFFER (parent));
  return 0;
}

Joseph Arceneaux's avatar
Joseph Arceneaux committed
607
/* Find the interval containing text position POSITION in the text
608
   represented by the interval tree TREE.  POSITION is a buffer
609 610 611
   position (starting from 1) or a string index (starting from 0).
   If POSITION is at the end of the buffer or string,
   return the interval containing the last character.
Joseph Arceneaux's avatar
Joseph Arceneaux committed
612

Joseph Arceneaux's avatar
Joseph Arceneaux committed
613 614
   The `position' field, which is a cache of an interval's position,
   is updated in the interval found.  Other functions (e.g., next_interval)
615
   will update this cache based on the result of find_interval.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
616

617
INTERVAL
618
find_interval (register INTERVAL tree, register EMACS_INT position)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
619
{
620 621
  /* The distance from the left edge of the subtree at TREE
                    to POSITION.  */
622
  register EMACS_INT relative_position;
Joseph Arceneaux's avatar
Joseph Arceneaux committed
623 624 625 626

  if (NULL_INTERVAL_P (tree))
    return NULL_INTERVAL;

627
  relative_position = position;
628 629 630 631 632 633 634
  if (INTERVAL_HAS_OBJECT (tree))
    {
      Lisp_Object parent;
      GET_INTERVAL_OBJECT (parent, tree);
      if (BUFFERP (parent))
	relative_position -= BUF_BEG (XBUFFER (parent));
    }
635

636
  if (relative_position > TOTAL_LENGTH (tree))
Joseph Arceneaux's avatar
Joseph Arceneaux committed
637 638
    abort ();			/* Paranoia */

639 640
  if (!handling_signal)
    tree = balance_possible_root_interval (tree);
641

Joseph Arceneaux's avatar
Joseph Arceneaux committed
642 643
  while (1)
    {
644
      if (relative_position < LEFT_TOTAL_LENGTH (tree))
Joseph Arceneaux's avatar
Joseph Arceneaux committed
645 646 647
	{
	  tree = tree->left;
	}
648 649 650
      else if (! NULL_RIGHT_CHILD (tree)
	       && relative_position >= (TOTAL_LENGTH (tree)
					- RIGHT_TOTAL_LENGTH (tree)))
Joseph Arceneaux's avatar
Joseph Arceneaux committed
651 652 653 654 655 656 657
	{
	  relative_position -= (TOTAL_LENGTH (tree)
				- RIGHT_TOTAL_LENGTH (tree));
	  tree = tree->right;
	}
      else
	{
658
	  tree->position
659 660
	    = (position - relative_position /* left edge of *tree.  */
	       + LEFT_TOTAL_LENGTH (tree)); /* left edge of this interval.  */
661

Joseph Arceneaux's avatar
Joseph Arceneaux committed
662 663 664 665 666 667
	  return tree;
	}
    }
}

/* Find the succeeding interval (lexicographically) to INTERVAL.
Joseph Arceneaux's avatar
Joseph Arceneaux committed
668
   Sets the `position' field based on that of INTERVAL (see
669
   find_interval).  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
670 671

INTERVAL
672
next_interval (register INTERVAL interval)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
673 674
{
  register INTERVAL i = interval;
675
  register EMACS_INT next_position;
Joseph Arceneaux's avatar
Joseph Arceneaux committed
676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694

  if (NULL_INTERVAL_P (i))
    return NULL_INTERVAL;
  next_position = interval->position + LENGTH (interval);

  if (! NULL_RIGHT_CHILD (i))
    {
      i = i->right;
      while (! NULL_LEFT_CHILD (i))
	i = i->left;

      i->position = next_position;
      return i;
    }

  while (! NULL_PARENT (i))
    {
      if (AM_LEFT_CHILD (i))
	{
695
	  i = INTERVAL_PARENT (i);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
696 697 698 699
	  i->position = next_position;
	  return i;
	}

700
      i = INTERVAL_PARENT (i);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
701 702 703 704 705 706
    }

  return NULL_INTERVAL;
}

/* Find the preceding interval (lexicographically) to INTERVAL.
Joseph Arceneaux's avatar
Joseph Arceneaux committed
707
   Sets the `position' field based on that of INTERVAL (see
708
   find_interval).  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
709 710

INTERVAL
711
previous_interval (register INTERVAL interval)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732
{
  register INTERVAL i;

  if (NULL_INTERVAL_P (interval))
    return NULL_INTERVAL;

  if (! NULL_LEFT_CHILD (interval))
    {
      i = interval->left;
      while (! NULL_RIGHT_CHILD (i))
	i = i->right;

      i->position = interval->position - LENGTH (i);
      return i;
    }

  i = interval;
  while (! NULL_PARENT (i))
    {
      if (AM_RIGHT_CHILD (i))
	{
733
	  i = INTERVAL_PARENT (i);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
734 735 736 737

	  i->position = interval->position - LENGTH (i);
	  return i;
	}
738
      i = INTERVAL_PARENT (i);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
739 740 741 742
    }

  return NULL_INTERVAL;
}
743 744

/* Find the interval containing POS given some non-NULL INTERVAL
745
   in the same tree.  Note that we need to update interval->position
746 747 748
   if we go down the tree.
   To speed up the process, we assume that the ->position of
   I and all its parents is already uptodate.  */
749
INTERVAL
750
update_interval (register INTERVAL i, EMACS_INT pos)
751 752 753 754
{
  if (NULL_INTERVAL_P (i))
    return NULL_INTERVAL;

Juanma Barranquero's avatar
Juanma Barranquero committed
755
  while (1)
756
    {
Juanma Barranquero's avatar
Juanma Barranquero committed
757
      if (pos < i->position)
758 759
	{
	  /* Move left. */
Juanma Barranquero's avatar
Juanma Barranquero committed
760
	  if (pos >= i->position - TOTAL_LENGTH (i->left))
761 762 763 764 765
	    {
	      i->left->position = i->position - TOTAL_LENGTH (i->left)
		+ LEFT_TOTAL_LENGTH (i->left);
	      i = i->left;		/* Move to the left child */
	    }
Juanma Barranquero's avatar
Juanma Barranquero committed
766
	  else if (NULL_PARENT (i))
767
	    error ("Point before start of properties");
Juanma Barranquero's avatar
Juanma Barranquero committed
768
	  else
769
	      i = INTERVAL_PARENT (i);
770 771 772 773 774
	  continue;
	}
      else if (pos >= INTERVAL_LAST_POS (i))
	{
	  /* Move right. */
Juanma Barranquero's avatar
Juanma Barranquero committed
775
	  if (pos < INTERVAL_LAST_POS (i) + TOTAL_LENGTH (i->right))
776
	    {
777 778
	      i->right->position = INTERVAL_LAST_POS (i)
	        + LEFT_TOTAL_LENGTH (i->right);
779 780
	      i = i->right;		/* Move to the right child */
	    }
Juanma Barranquero's avatar
Juanma Barranquero committed
781
	  else if (NULL_PARENT (i))
782
	    error ("Point %"pI"d after end of properties", pos);
Juanma Barranquero's avatar
Juanma Barranquero committed
783
	  else
784
            i = INTERVAL_PARENT (i);
785 786
	  continue;
	}
Juanma Barranquero's avatar
Juanma Barranquero committed
787
      else
788 789 790 791
	return i;
    }
}

Joseph Arceneaux's avatar
Joseph Arceneaux committed
792

Joseph Arceneaux's avatar
Joseph Arceneaux committed
793
#if 0
Joseph Arceneaux's avatar
Joseph Arceneaux committed
794 795 796 797 798 799 800 801 802
/* Traverse a path down the interval tree TREE to the interval
   containing POSITION, adjusting all nodes on the path for
   an addition of LENGTH characters.  Insertion between two intervals
   (i.e., point == i->position, where i is second interval) means
   text goes into second interval.

   Modifications are needed to handle the hungry bits -- after simply
   finding the interval at position (don't add length going down),
   if it's the beginning of the interval, get the previous interval
Karl Heuer's avatar
Karl Heuer committed
803
   and check the hungry bits of both.  Then add the length going back up
804
   to the root.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
805 806 807 808

static INTERVAL
adjust_intervals_for_insertion (tree, position, length)
     INTERVAL tree;
809
     EMACS_INT position, length;
Joseph Arceneaux's avatar
Joseph Arceneaux committed
810
{
811
  register EMACS_INT relative_position;
Joseph Arceneaux's avatar
Joseph Arceneaux committed
812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828
  register INTERVAL this;

  if (TOTAL_LENGTH (tree) == 0)	/* Paranoia */
    abort ();

  /* If inserting at point-max of a buffer, that position
     will be out of range */
  if (position > TOTAL_LENGTH (tree))
    position = TOTAL_LENGTH (tree);
  relative_position = position;
  this = tree;

  while (1)
    {
      if (relative_position <= LEFT_TOTAL_LENGTH (this))
	{
	  this->total_length += length;
829
	  CHECK_TOTAL_LENGTH (this);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
830 831 832 833 834 835 836 837
	  this = this->left;
	}
      else if (relative_position > (TOTAL_LENGTH (this)
				    - RIGHT_TOTAL_LENGTH (this)))
	{
	  relative_position -= (TOTAL_LENGTH (this)
				- RIGHT_TOTAL_LENGTH (this));
	  this->total_length += length;
838
	  CHECK_TOTAL_LENGTH (this);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
839 840 841 842 843
	  this = this->right;
	}
      else
	{
	  /* If we are to use zero-length intervals as buffer pointers,
844
	     then this code will have to change.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
845
	  this->total_length += length;
846
	  CHECK_TOTAL_LENGTH (this);
Joseph Arceneaux's avatar
Joseph Arceneaux committed
847 848 849 850 851 852
	  this->position = LEFT_TOTAL_LENGTH (this)
	                   + position - relative_position + 1;
	  return tree;
	}
    }
}
Joseph Arceneaux's avatar
Joseph Arceneaux committed
853 854 855 856
#endif

/* Effect an adjustment corresponding to the addition of LENGTH characters
   of text.  Do this by finding the interval containing POSITION in the
857
   interval tree TREE, and then adjusting all of its ancestors by adding
Joseph Arceneaux's avatar
Joseph Arceneaux committed
858 859 860 861 862 863
   LENGTH to them.

   If POSITION is the first character of an interval, meaning that point
   is actually between the two intervals, make the new text belong to
   the interval which is "sticky".

Joseph Arceneaux's avatar
Joseph Arceneaux committed
864
   If both intervals are "sticky", then make them belong to the left-most
Joseph Arceneaux's avatar
Joseph Arceneaux committed
865
   interval.  Another possibility would be to create a new interval for
866
   this text, and make it have the merged properties of both ends.  */
Joseph Arceneaux's avatar
Joseph Arceneaux committed
867 868

static INTERVAL
869 870
adjust_intervals_for_insertion (INTERVAL tree,
				EMACS_INT position, EMACS_INT length)
Joseph Arceneaux's avatar
Joseph Arceneaux committed
871 872
{
  register INTERVAL i;
873 874
  register INTERVAL temp;
  int eobp = 0;
875
  Lisp_Object parent;
876
  EMACS_INT offset;
Juanma Barranquero's avatar
Juanma Barranquero committed
877

Joseph Arceneaux's avatar
Joseph Arceneaux committed
878 879 880
  if (TOTAL_LENGTH (tree) == 0)	/* Paranoia */
    abort ();

881
  GET_INTERVAL_OBJECT (parent, tree);
882 883
  offset = (BUFFERP (parent) ? BUF_BEG (XBUFFER (parent)) : 0);

884 885
  /* If inserting at point-max of a buffer, that position will be out
     of range.  Remember that buffer positions are 1-based.  */
886 887 888 889 890
  if (position >= TOTAL_LENGTH (tree) + offset)
    {
      position = TOTAL_LENGTH (tree) + offset;
      eobp = 1;
    }
Joseph Arceneaux's avatar
Joseph Arceneaux committed
891 892

  i = find_interval (tree, position);
893

894 895
  /* If in middle of an interval which is not sticky either way,
     we must not just give its properties to the insertion.
896 897 898 899 900 901 902 903 904 905
     So split this interval at the insertion point.

     Originally, the if condition here was this:
	(! (position == i->position || eobp)
	 && END_NONSTICKY_P (i)
	 && FRONT_NONSTICKY_P (i))
     But, these macros are now unreliable because of introduction of
     Vtext_property_default_nonsticky.  So, we always check properties
     one by one if POSITION is in middle of an interval.  */
  if (! (position == i->position || eobp))
906
    {
907 908 909
      Lisp_Object tail;
      Lisp_Object front, rear;

910 911 912 913 914 915 916 917 918 919 920
      tail = i->plist;

      /* Properties font-sticky and rear-nonsticky override
         Vtext_property_default_nonsticky.  So, if they are t, we can
         skip one by one checking of properties.  */
      rear = textget (i->plist, Qrear_nonsticky);
      if (! CONSP (rear) && ! NILP (rear))
	{
	  /* All properties are nonsticky.  We split the interval.  */
	  goto check_done;
	}
921
      front = textget (i->plist, Qfront_sticky);
922 923 924 925 926 927
      if (! CONSP (front) && ! NILP (front))
	{
	  /* All properties are sticky.  We don't split the interval.  */
	  tail = Qnil;
	  goto check_done;
	}
928

929 930 931
      /* Does any actual property pose an actual problem?  We break
         the loop if we find a nonsticky property.  */
      for (; CONSP (tail); tail = Fcdr (XCDR (tail)))
932
	{
933
	  Lisp_Object prop, tmp;
934
	  prop = XCAR (tail);
935

936
	  /* Is this particular property front-sticky?  */
937 938 939
	  if (CONSP (front) && ! NILP (Fmemq (prop, front)))
	    continue;

940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955
	  /* Is this particular property rear-nonsticky?  */
	  if (CONSP (rear) && ! NILP (Fmemq (prop, rear)))
	    break;

	  /* Is this particular property recorded as sticky or
             nonsticky in Vtext_property_default_nonsticky?  */
	  tmp = Fassq (prop, Vtext_property_default_nonsticky);
	  if (CONSP (tmp))
	    {
	      if (NILP (tmp))
		continue;
	      break;
	    }

	  /* By default, a text property is rear-sticky, thus we
	     continue the loop.  */
956 957
	}

958
    check_done:
959 960 961 962 963 964 965
      /* If any property is a real problem, split the interval.  */
      if (! NILP (tail))
	{
	  temp = split_interval_right (i, position - i->position);
	  copy_properties (i, temp);
	  i = temp;
	}
966 967
    }

Joseph Arceneaux's avatar
Joseph Arceneaux committed
968
  /* If we are positioned between intervals, check the stickiness of
969 970
     both of them.  We have to do this too, if we are at BEG or Z.  */
  if (position == i->position || eobp)