1 /* Code for doing intervals.
2 Copyright (C) 1993, 1994, 1995 Free Software Foundation, Inc.
4 This file is part of GNU Emacs.
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 2, or (at your option)
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.
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, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
24 Have to ensure that we can't put symbol nil on a plist, or some
25 functions may work incorrectly.
27 An idea: Have the owner of the tree keep count of splits and/or
28 insertion lengths (in intervals), and balance after every N.
30 Need to call *_left_hook when buffer is killed.
32 Scan for zero-length, or 0-length to see notes about handling
33 zero length interval-markers.
35 There are comments around about freeing intervals. It might be
36 faster to explicitly free them (put them on the free list) than
44 #include "intervals.h"
49 /* The rest of the file is within this conditional. */
50 #ifdef USE_TEXT_PROPERTIES
52 /* Test for membership, allowing for t (actually any non-cons) to mean the
55 #define TMEM(sym, set) (CONSP (set) ? ! NILP (Fmemq (sym, set)) : ! NILP (set))
57 #define min(x, y) ((x) < (y) ? (x) : (y))
59 Lisp_Object
merge_properties_sticky ();
61 /* Utility functions for intervals. */
64 /* Create the root interval of some object, a buffer or string. */
67 create_root_interval (parent
)
72 CHECK_IMPURE (parent
);
74 new = make_interval ();
78 new->total_length
= (BUF_Z (XBUFFER (parent
))
79 - BUF_BEG (XBUFFER (parent
)));
80 BUF_INTERVALS (XBUFFER (parent
)) = new;
82 else if (STRINGP (parent
))
84 new->total_length
= XSTRING (parent
)->size
;
85 XSTRING (parent
)->intervals
= new;
88 new->parent
= (INTERVAL
) parent
;
94 /* Make the interval TARGET have exactly the properties of SOURCE */
97 copy_properties (source
, target
)
98 register INTERVAL source
, target
;
100 if (DEFAULT_INTERVAL_P (source
) && DEFAULT_INTERVAL_P (target
))
103 COPY_INTERVAL_CACHE (source
, target
);
104 target
->plist
= Fcopy_sequence (source
->plist
);
107 /* Merge the properties of interval SOURCE into the properties
108 of interval TARGET. That is to say, each property in SOURCE
109 is added to TARGET if TARGET has no such property as yet. */
112 merge_properties (source
, target
)
113 register INTERVAL source
, target
;
115 register Lisp_Object o
, sym
, val
;
117 if (DEFAULT_INTERVAL_P (source
) && DEFAULT_INTERVAL_P (target
))
120 MERGE_INTERVAL_CACHE (source
, target
);
123 while (! EQ (o
, Qnil
))
126 val
= Fmemq (sym
, target
->plist
);
132 target
->plist
= Fcons (sym
, Fcons (val
, target
->plist
));
140 /* Return 1 if the two intervals have the same properties,
144 intervals_equal (i0
, i1
)
147 register Lisp_Object i0_cdr
, i0_sym
, i1_val
;
150 if (DEFAULT_INTERVAL_P (i0
) && DEFAULT_INTERVAL_P (i1
))
153 if (DEFAULT_INTERVAL_P (i0
) || DEFAULT_INTERVAL_P (i1
))
156 i1_len
= XFASTINT (Flength (i1
->plist
));
157 if (i1_len
& 0x1) /* Paranoia -- plists are always even */
161 while (!NILP (i0_cdr
))
163 /* Lengths of the two plists were unequal. */
167 i0_sym
= Fcar (i0_cdr
);
168 i1_val
= Fmemq (i0_sym
, i1
->plist
);
170 /* i0 has something i1 doesn't. */
171 if (EQ (i1_val
, Qnil
))
174 /* i0 and i1 both have sym, but it has different values in each. */
175 i0_cdr
= Fcdr (i0_cdr
);
176 if (! EQ (Fcar (Fcdr (i1_val
)), Fcar (i0_cdr
)))
179 i0_cdr
= Fcdr (i0_cdr
);
183 /* Lengths of the two plists were unequal. */
192 static int zero_length
;
194 /* Traverse an interval tree TREE, performing FUNCTION on each node.
195 Pass FUNCTION two args: an interval, and ARG. */
198 traverse_intervals (tree
, position
, depth
, function
, arg
)
201 void (* function
) ();
204 if (NULL_INTERVAL_P (tree
))
207 traverse_intervals (tree
->left
, position
, depth
+ 1, function
, arg
);
208 position
+= LEFT_TOTAL_LENGTH (tree
);
209 tree
->position
= position
;
210 (*function
) (tree
, arg
);
211 position
+= LENGTH (tree
);
212 traverse_intervals (tree
->right
, position
, depth
+ 1, function
, arg
);
216 /* These functions are temporary, for debugging purposes only. */
218 INTERVAL search_interval
, found_interval
;
221 check_for_interval (i
)
224 if (i
== search_interval
)
232 search_for_interval (i
, tree
)
233 register INTERVAL i
, tree
;
237 found_interval
= NULL_INTERVAL
;
238 traverse_intervals (tree
, 1, 0, &check_for_interval
, Qnil
);
239 return found_interval
;
243 inc_interval_count (i
)
260 traverse_intervals (i
, 1, 0, &inc_interval_count
, Qnil
);
266 root_interval (interval
)
269 register INTERVAL i
= interval
;
271 while (! ROOT_INTERVAL_P (i
))
278 /* Assuming that a left child exists, perform the following operation:
288 rotate_right (interval
)
292 INTERVAL B
= interval
->left
;
293 int old_total
= interval
->total_length
;
295 /* Deal with any Parent of A; make it point to B. */
296 if (! ROOT_INTERVAL_P (interval
))
297 if (AM_LEFT_CHILD (interval
))
298 interval
->parent
->left
= B
;
300 interval
->parent
->right
= B
;
301 B
->parent
= interval
->parent
;
303 /* Make B the parent of A */
306 interval
->parent
= B
;
308 /* Make A point to c */
310 if (! NULL_INTERVAL_P (i
))
311 i
->parent
= interval
;
313 /* A's total length is decreased by the length of B and its left child. */
314 interval
->total_length
-= B
->total_length
- LEFT_TOTAL_LENGTH (interval
);
316 /* B must have the same total length of A. */
317 B
->total_length
= old_total
;
322 /* Assuming that a right child exists, perform the following operation:
332 rotate_left (interval
)
336 INTERVAL B
= interval
->right
;
337 int old_total
= interval
->total_length
;
339 /* Deal with any parent of A; make it point to B. */
340 if (! ROOT_INTERVAL_P (interval
))
341 if (AM_LEFT_CHILD (interval
))
342 interval
->parent
->left
= B
;
344 interval
->parent
->right
= B
;
345 B
->parent
= interval
->parent
;
347 /* Make B the parent of A */
350 interval
->parent
= B
;
352 /* Make A point to c */
354 if (! NULL_INTERVAL_P (i
))
355 i
->parent
= interval
;
357 /* A's total length is decreased by the length of B and its right child. */
358 interval
->total_length
-= B
->total_length
- RIGHT_TOTAL_LENGTH (interval
);
360 /* B must have the same total length of A. */
361 B
->total_length
= old_total
;
366 /* Balance an interval tree with the assumption that the subtrees
367 themselves are already balanced. */
370 balance_an_interval (i
)
373 register int old_diff
, new_diff
;
377 old_diff
= LEFT_TOTAL_LENGTH (i
) - RIGHT_TOTAL_LENGTH (i
);
380 new_diff
= i
->total_length
- i
->left
->total_length
381 + RIGHT_TOTAL_LENGTH (i
->left
) - LEFT_TOTAL_LENGTH (i
->left
);
382 if (abs (new_diff
) >= old_diff
)
384 i
= rotate_right (i
);
385 balance_an_interval (i
->right
);
387 else if (old_diff
< 0)
389 new_diff
= i
->total_length
- i
->right
->total_length
390 + LEFT_TOTAL_LENGTH (i
->right
) - RIGHT_TOTAL_LENGTH (i
->right
);
391 if (abs (new_diff
) >= -old_diff
)
394 balance_an_interval (i
->left
);
402 /* Balance INTERVAL, potentially stuffing it back into its parent
405 static INLINE INTERVAL
406 balance_possible_root_interval (interval
)
407 register INTERVAL interval
;
411 if (interval
->parent
== NULL_INTERVAL
)
414 parent
= (Lisp_Object
) (interval
->parent
);
415 interval
= balance_an_interval (interval
);
417 if (BUFFERP (parent
))
418 BUF_INTERVALS (XBUFFER (parent
)) = interval
;
419 else if (STRINGP (parent
))
420 XSTRING (parent
)->intervals
= interval
;
425 /* Balance the interval tree TREE. Balancing is by weight
426 (the amount of text). */
429 balance_intervals_internal (tree
)
430 register INTERVAL tree
;
432 /* Balance within each side. */
434 balance_intervals_internal (tree
->left
);
436 balance_intervals_internal (tree
->right
);
437 return balance_an_interval (tree
);
440 /* Advertised interface to balance intervals. */
443 balance_intervals (tree
)
446 if (tree
== NULL_INTERVAL
)
447 return NULL_INTERVAL
;
449 return balance_intervals_internal (tree
);
452 /* Split INTERVAL into two pieces, starting the second piece at
453 character position OFFSET (counting from 0), relative to INTERVAL.
454 INTERVAL becomes the left-hand piece, and the right-hand piece
455 (second, lexicographically) is returned.
457 The size and position fields of the two intervals are set based upon
458 those of the original interval. The property list of the new interval
459 is reset, thus it is up to the caller to do the right thing with the
462 Note that this does not change the position of INTERVAL; if it is a root,
463 it is still a root after this operation. */
466 split_interval_right (interval
, offset
)
470 INTERVAL
new = make_interval ();
471 int position
= interval
->position
;
472 int new_length
= LENGTH (interval
) - offset
;
474 new->position
= position
+ offset
;
475 new->parent
= interval
;
477 if (NULL_RIGHT_CHILD (interval
))
479 interval
->right
= new;
480 new->total_length
= new_length
;
485 /* Insert the new node between INTERVAL and its right child. */
486 new->right
= interval
->right
;
487 interval
->right
->parent
= new;
488 interval
->right
= new;
489 new->total_length
= new_length
+ new->right
->total_length
;
491 balance_an_interval (new);
492 balance_possible_root_interval (interval
);
497 /* Split INTERVAL into two pieces, starting the second piece at
498 character position OFFSET (counting from 0), relative to INTERVAL.
499 INTERVAL becomes the right-hand piece, and the left-hand piece
500 (first, lexicographically) is returned.
502 The size and position fields of the two intervals are set based upon
503 those of the original interval. The property list of the new interval
504 is reset, thus it is up to the caller to do the right thing with the
507 Note that this does not change the position of INTERVAL; if it is a root,
508 it is still a root after this operation. */
511 split_interval_left (interval
, offset
)
515 INTERVAL
new = make_interval ();
516 int position
= interval
->position
;
517 int new_length
= offset
;
519 new->position
= interval
->position
;
520 interval
->position
= interval
->position
+ offset
;
521 new->parent
= interval
;
523 if (NULL_LEFT_CHILD (interval
))
525 interval
->left
= new;
526 new->total_length
= new_length
;
531 /* Insert the new node between INTERVAL and its left child. */
532 new->left
= interval
->left
;
533 new->left
->parent
= new;
534 interval
->left
= new;
535 new->total_length
= new_length
+ new->left
->total_length
;
537 balance_an_interval (new);
538 balance_possible_root_interval (interval
);
543 /* Find the interval containing text position POSITION in the text
544 represented by the interval tree TREE. POSITION is a buffer
545 position; the earliest position is 1. If POSITION is at the end of
546 the buffer, return the interval containing the last character.
548 The `position' field, which is a cache of an interval's position,
549 is updated in the interval found. Other functions (e.g., next_interval)
550 will update this cache based on the result of find_interval. */
553 find_interval (tree
, position
)
554 register INTERVAL tree
;
555 register int position
;
557 /* The distance from the left edge of the subtree at TREE
559 register int relative_position
= position
- BEG
;
561 if (NULL_INTERVAL_P (tree
))
562 return NULL_INTERVAL
;
564 if (relative_position
> TOTAL_LENGTH (tree
))
565 abort (); /* Paranoia */
567 tree
= balance_possible_root_interval (tree
);
571 if (relative_position
< LEFT_TOTAL_LENGTH (tree
))
575 else if (! NULL_RIGHT_CHILD (tree
)
576 && relative_position
>= (TOTAL_LENGTH (tree
)
577 - RIGHT_TOTAL_LENGTH (tree
)))
579 relative_position
-= (TOTAL_LENGTH (tree
)
580 - RIGHT_TOTAL_LENGTH (tree
));
586 (position
- relative_position
/* the left edge of *tree */
587 + LEFT_TOTAL_LENGTH (tree
)); /* the left edge of this interval */
594 /* Find the succeeding interval (lexicographically) to INTERVAL.
595 Sets the `position' field based on that of INTERVAL (see
599 next_interval (interval
)
600 register INTERVAL interval
;
602 register INTERVAL i
= interval
;
603 register int next_position
;
605 if (NULL_INTERVAL_P (i
))
606 return NULL_INTERVAL
;
607 next_position
= interval
->position
+ LENGTH (interval
);
609 if (! NULL_RIGHT_CHILD (i
))
612 while (! NULL_LEFT_CHILD (i
))
615 i
->position
= next_position
;
619 while (! NULL_PARENT (i
))
621 if (AM_LEFT_CHILD (i
))
624 i
->position
= next_position
;
631 return NULL_INTERVAL
;
634 /* Find the preceding interval (lexicographically) to INTERVAL.
635 Sets the `position' field based on that of INTERVAL (see
639 previous_interval (interval
)
640 register INTERVAL interval
;
643 register position_of_previous
;
645 if (NULL_INTERVAL_P (interval
))
646 return NULL_INTERVAL
;
648 if (! NULL_LEFT_CHILD (interval
))
651 while (! NULL_RIGHT_CHILD (i
))
654 i
->position
= interval
->position
- LENGTH (i
);
659 while (! NULL_PARENT (i
))
661 if (AM_RIGHT_CHILD (i
))
665 i
->position
= interval
->position
- LENGTH (i
);
671 return NULL_INTERVAL
;
675 /* Traverse a path down the interval tree TREE to the interval
676 containing POSITION, adjusting all nodes on the path for
677 an addition of LENGTH characters. Insertion between two intervals
678 (i.e., point == i->position, where i is second interval) means
679 text goes into second interval.
681 Modifications are needed to handle the hungry bits -- after simply
682 finding the interval at position (don't add length going down),
683 if it's the beginning of the interval, get the previous interval
684 and check the hungry bits of both. Then add the length going back up
688 adjust_intervals_for_insertion (tree
, position
, length
)
690 int position
, length
;
692 register int relative_position
;
693 register INTERVAL
this;
695 if (TOTAL_LENGTH (tree
) == 0) /* Paranoia */
698 /* If inserting at point-max of a buffer, that position
699 will be out of range */
700 if (position
> TOTAL_LENGTH (tree
))
701 position
= TOTAL_LENGTH (tree
);
702 relative_position
= position
;
707 if (relative_position
<= LEFT_TOTAL_LENGTH (this))
709 this->total_length
+= length
;
712 else if (relative_position
> (TOTAL_LENGTH (this)
713 - RIGHT_TOTAL_LENGTH (this)))
715 relative_position
-= (TOTAL_LENGTH (this)
716 - RIGHT_TOTAL_LENGTH (this));
717 this->total_length
+= length
;
722 /* If we are to use zero-length intervals as buffer pointers,
723 then this code will have to change. */
724 this->total_length
+= length
;
725 this->position
= LEFT_TOTAL_LENGTH (this)
726 + position
- relative_position
+ 1;
733 /* Effect an adjustment corresponding to the addition of LENGTH characters
734 of text. Do this by finding the interval containing POSITION in the
735 interval tree TREE, and then adjusting all of its ancestors by adding
738 If POSITION is the first character of an interval, meaning that point
739 is actually between the two intervals, make the new text belong to
740 the interval which is "sticky".
742 If both intervals are "sticky", then make them belong to the left-most
743 interval. Another possibility would be to create a new interval for
744 this text, and make it have the merged properties of both ends. */
747 adjust_intervals_for_insertion (tree
, position
, length
)
749 int position
, length
;
752 register INTERVAL temp
;
755 if (TOTAL_LENGTH (tree
) == 0) /* Paranoia */
758 /* If inserting at point-max of a buffer, that position will be out
759 of range. Remember that buffer positions are 1-based. */
760 if (position
>= BEG
+ TOTAL_LENGTH (tree
)){
761 position
= BEG
+ TOTAL_LENGTH (tree
);
765 i
= find_interval (tree
, position
);
767 /* If in middle of an interval which is not sticky either way,
768 we must not just give its properties to the insertion.
769 So split this interval at the insertion point. */
770 if (! (position
== i
->position
|| eobp
)
771 && END_NONSTICKY_P (i
)
772 && ! FRONT_STICKY_P (i
))
774 temp
= split_interval_right (i
, position
- i
->position
);
775 copy_properties (i
, temp
);
779 /* If we are positioned between intervals, check the stickiness of
780 both of them. We have to do this too, if we are at BEG or Z. */
781 if (position
== i
->position
|| eobp
)
783 register INTERVAL prev
;
793 prev
= previous_interval (i
);
795 /* Even if we are positioned between intervals, we default
796 to the left one if it exists. We extend it now and split
797 off a part later, if stickiness demands it. */
798 for (temp
= prev
? prev
: i
;! NULL_INTERVAL_P (temp
); temp
= temp
->parent
)
800 temp
->total_length
+= length
;
801 temp
= balance_possible_root_interval (temp
);
804 /* If at least one interval has sticky properties,
805 we check the stickiness property by property. */
806 if (END_NONSTICKY_P (prev
) || FRONT_STICKY_P (i
))
808 Lisp_Object pleft
, pright
;
809 struct interval newi
;
811 pleft
= NULL_INTERVAL_P (prev
) ? Qnil
: prev
->plist
;
812 pright
= NULL_INTERVAL_P (i
) ? Qnil
: i
->plist
;
813 newi
.plist
= merge_properties_sticky (pleft
, pright
);
815 if(! prev
) /* i.e. position == BEG */
817 if (! intervals_equal (i
, &newi
))
819 i
= split_interval_left (i
, length
);
820 i
->plist
= newi
.plist
;
823 else if (! intervals_equal (prev
, &newi
))
825 prev
= split_interval_right (prev
,
826 position
- prev
->position
);
827 prev
->plist
= newi
.plist
;
828 if (! NULL_INTERVAL_P (i
)
829 && intervals_equal (prev
, i
))
830 merge_interval_right (prev
);
833 /* We will need to update the cache here later. */
835 else if (! prev
&& ! NILP (i
->plist
))
837 /* Just split off a new interval at the left.
838 Since I wasn't front-sticky, the empty plist is ok. */
839 i
= split_interval_left (i
, length
);
843 /* Otherwise just extend the interval. */
846 for (temp
= i
; ! NULL_INTERVAL_P (temp
); temp
= temp
->parent
)
848 temp
->total_length
+= length
;
849 temp
= balance_possible_root_interval (temp
);
856 /* Any property might be front-sticky on the left, rear-sticky on the left,
857 front-sticky on the right, or rear-sticky on the right; the 16 combinations
858 can be arranged in a matrix with rows denoting the left conditions and
859 columns denoting the right conditions:
867 left-props = '(front-sticky (p8 p9 pa pb pc pd pe pf)
868 rear-nonsticky (p4 p5 p6 p7 p8 p9 pa pb)
869 p0 L p1 L p2 L p3 L p4 L p5 L p6 L p7 L
870 p8 L p9 L pa L pb L pc L pd L pe L pf L)
871 right-props = '(front-sticky (p2 p3 p6 p7 pa pb pe pf)
872 rear-nonsticky (p1 p2 p5 p6 p9 pa pd pe)
873 p0 R p1 R p2 R p3 R p4 R p5 R p6 R p7 R
874 p8 R p9 R pa R pb R pc R pd R pe R pf R)
876 We inherit from whoever has a sticky side facing us. If both sides
877 do (cases 2, 3, E, and F), then we inherit from whichever side has a
878 non-nil value for the current property. If both sides do, then we take
881 When we inherit a property, we get its stickiness as well as its value.
882 So, when we merge the above two lists, we expect to get this:
884 result = '(front-sticky (p6 p7 pa pb pc pd pe pf)
885 rear-nonsticky (p6 pa)
886 p0 L p1 L p2 L p3 L p6 R p7 R
887 pa R pb R pc L pd L pe L pf L)
889 The optimizable special cases are:
890 left rear-nonsticky = nil, right front-sticky = nil (inherit left)
891 left rear-nonsticky = t, right front-sticky = t (inherit right)
892 left rear-nonsticky = t, right front-sticky = nil (inherit none)
896 merge_properties_sticky (pleft
, pright
)
897 Lisp_Object pleft
, pright
;
899 register Lisp_Object props
, front
, rear
;
900 Lisp_Object lfront
, lrear
, rfront
, rrear
;
901 register Lisp_Object tail1
, tail2
, sym
, lval
, rval
, cat
;
902 int use_left
, use_right
;
908 lfront
= textget (pleft
, Qfront_sticky
);
909 lrear
= textget (pleft
, Qrear_nonsticky
);
910 rfront
= textget (pright
, Qfront_sticky
);
911 rrear
= textget (pright
, Qrear_nonsticky
);
913 /* Go through each element of PRIGHT. */
914 for (tail1
= pright
; ! NILP (tail1
); tail1
= Fcdr (Fcdr (tail1
)))
918 /* Sticky properties get special treatment. */
919 if (EQ (sym
, Qrear_nonsticky
) || EQ (sym
, Qfront_sticky
))
922 rval
= Fcar (Fcdr (tail1
));
923 for (tail2
= pleft
; ! NILP (tail2
); tail2
= Fcdr (Fcdr (tail2
)))
924 if (EQ (sym
, Fcar (tail2
)))
927 /* Indicate whether the property is explicitly defined on the left.
928 (We know it is defined explicitly on the right
929 because otherwise we don't get here.) */
930 lpresent
= ! NILP (tail2
);
931 lval
= (NILP (tail2
) ? Qnil
: Fcar (Fcdr (tail2
)));
933 use_left
= ! TMEM (sym
, lrear
) && lpresent
;
934 use_right
= TMEM (sym
, rfront
);
935 if (use_left
&& use_right
)
939 else if (NILP (rval
))
944 /* We build props as (value sym ...) rather than (sym value ...)
945 because we plan to nreverse it when we're done. */
946 props
= Fcons (lval
, Fcons (sym
, props
));
947 if (TMEM (sym
, lfront
))
948 front
= Fcons (sym
, front
);
949 if (TMEM (sym
, lrear
))
950 rear
= Fcons (sym
, rear
);
954 props
= Fcons (rval
, Fcons (sym
, props
));
955 if (TMEM (sym
, rfront
))
956 front
= Fcons (sym
, front
);
957 if (TMEM (sym
, rrear
))
958 rear
= Fcons (sym
, rear
);
962 /* Now go through each element of PLEFT. */
963 for (tail2
= pleft
; ! NILP (tail2
); tail2
= Fcdr (Fcdr (tail2
)))
967 /* Sticky properties get special treatment. */
968 if (EQ (sym
, Qrear_nonsticky
) || EQ (sym
, Qfront_sticky
))
971 /* If sym is in PRIGHT, we've already considered it. */
972 for (tail1
= pright
; ! NILP (tail1
); tail1
= Fcdr (Fcdr (tail1
)))
973 if (EQ (sym
, Fcar (tail1
)))
978 lval
= Fcar (Fcdr (tail2
));
980 /* Since rval is known to be nil in this loop, the test simplifies. */
981 if (! TMEM (sym
, lrear
))
983 props
= Fcons (lval
, Fcons (sym
, props
));
984 if (TMEM (sym
, lfront
))
985 front
= Fcons (sym
, front
);
987 else if (TMEM (sym
, rfront
))
989 /* The value is nil, but we still inherit the stickiness
991 front
= Fcons (sym
, front
);
992 if (TMEM (sym
, rrear
))
993 rear
= Fcons (sym
, rear
);
996 props
= Fnreverse (props
);
998 props
= Fcons (Qrear_nonsticky
, Fcons (Fnreverse (rear
), props
));
1000 cat
= textget (props
, Qcategory
);
1003 /* If we have inherited a front-stick category property that is t,
1004 we don't need to set up a detailed one. */
1005 ! (! NILP (cat
) && SYMBOLP (cat
)
1006 && EQ (Fget (cat
, Qfront_sticky
), Qt
)))
1007 props
= Fcons (Qfront_sticky
, Fcons (Fnreverse (front
), props
));
1012 /* Delete an node I from its interval tree by merging its subtrees
1013 into one subtree which is then returned. Caller is responsible for
1014 storing the resulting subtree into its parent. */
1018 register INTERVAL i
;
1020 register INTERVAL migrate
, this;
1021 register int migrate_amt
;
1023 if (NULL_INTERVAL_P (i
->left
))
1025 if (NULL_INTERVAL_P (i
->right
))
1029 migrate_amt
= i
->left
->total_length
;
1031 this->total_length
+= migrate_amt
;
1032 while (! NULL_INTERVAL_P (this->left
))
1035 this->total_length
+= migrate_amt
;
1037 this->left
= migrate
;
1038 migrate
->parent
= this;
1043 /* Delete interval I from its tree by calling `delete_node'
1044 and properly connecting the resultant subtree.
1046 I is presumed to be empty; that is, no adjustments are made
1047 for the length of I. */
1051 register INTERVAL i
;
1053 register INTERVAL parent
;
1054 int amt
= LENGTH (i
);
1056 if (amt
> 0) /* Only used on zero-length intervals now. */
1059 if (ROOT_INTERVAL_P (i
))
1062 owner
= (Lisp_Object
) i
->parent
;
1063 parent
= delete_node (i
);
1064 if (! NULL_INTERVAL_P (parent
))
1065 parent
->parent
= (INTERVAL
) owner
;
1067 if (BUFFERP (owner
))
1068 BUF_INTERVALS (XBUFFER (owner
)) = parent
;
1069 else if (STRINGP (owner
))
1070 XSTRING (owner
)->intervals
= parent
;
1078 if (AM_LEFT_CHILD (i
))
1080 parent
->left
= delete_node (i
);
1081 if (! NULL_INTERVAL_P (parent
->left
))
1082 parent
->left
->parent
= parent
;
1086 parent
->right
= delete_node (i
);
1087 if (! NULL_INTERVAL_P (parent
->right
))
1088 parent
->right
->parent
= parent
;
1092 /* Find the interval in TREE corresponding to the relative position
1093 FROM and delete as much as possible of AMOUNT from that interval.
1094 Return the amount actually deleted, and if the interval was
1095 zeroed-out, delete that interval node from the tree.
1097 Note that FROM is actually origin zero, aka relative to the
1098 leftmost edge of tree. This is appropriate since we call ourselves
1099 recursively on subtrees.
1101 Do this by recursing down TREE to the interval in question, and
1102 deleting the appropriate amount of text. */
1105 interval_deletion_adjustment (tree
, from
, amount
)
1106 register INTERVAL tree
;
1107 register int from
, amount
;
1109 register int relative_position
= from
;
1111 if (NULL_INTERVAL_P (tree
))
1115 if (relative_position
< LEFT_TOTAL_LENGTH (tree
))
1117 int subtract
= interval_deletion_adjustment (tree
->left
,
1120 tree
->total_length
-= subtract
;
1124 else if (relative_position
>= (TOTAL_LENGTH (tree
)
1125 - RIGHT_TOTAL_LENGTH (tree
)))
1129 relative_position
-= (tree
->total_length
1130 - RIGHT_TOTAL_LENGTH (tree
));
1131 subtract
= interval_deletion_adjustment (tree
->right
,
1134 tree
->total_length
-= subtract
;
1137 /* Here -- this node. */
1140 /* How much can we delete from this interval? */
1141 int my_amount
= ((tree
->total_length
1142 - RIGHT_TOTAL_LENGTH (tree
))
1143 - relative_position
);
1145 if (amount
> my_amount
)
1148 tree
->total_length
-= amount
;
1149 if (LENGTH (tree
) == 0)
1150 delete_interval (tree
);
1155 /* Never reach here. */
1158 /* Effect the adjustments necessary to the interval tree of BUFFER to
1159 correspond to the deletion of LENGTH characters from that buffer
1160 text. The deletion is effected at position START (which is a
1161 buffer position, i.e. origin 1). */
1164 adjust_intervals_for_deletion (buffer
, start
, length
)
1165 struct buffer
*buffer
;
1168 register int left_to_delete
= length
;
1169 register INTERVAL tree
= BUF_INTERVALS (buffer
);
1170 register int deleted
;
1172 if (NULL_INTERVAL_P (tree
))
1175 if (start
> BEG
+ TOTAL_LENGTH (tree
)
1176 || start
+ length
> BEG
+ TOTAL_LENGTH (tree
))
1179 if (length
== TOTAL_LENGTH (tree
))
1181 BUF_INTERVALS (buffer
) = NULL_INTERVAL
;
1185 if (ONLY_INTERVAL_P (tree
))
1187 tree
->total_length
-= length
;
1191 if (start
> BEG
+ TOTAL_LENGTH (tree
))
1192 start
= BEG
+ TOTAL_LENGTH (tree
);
1193 while (left_to_delete
> 0)
1195 left_to_delete
-= interval_deletion_adjustment (tree
, start
- 1,
1197 tree
= BUF_INTERVALS (buffer
);
1198 if (left_to_delete
== tree
->total_length
)
1200 BUF_INTERVALS (buffer
) = NULL_INTERVAL
;
1206 /* Make the adjustments necessary to the interval tree of BUFFER to
1207 represent an addition or deletion of LENGTH characters starting
1208 at position START. Addition or deletion is indicated by the sign
1212 offset_intervals (buffer
, start
, length
)
1213 struct buffer
*buffer
;
1216 if (NULL_INTERVAL_P (BUF_INTERVALS (buffer
)) || length
== 0)
1220 adjust_intervals_for_insertion (BUF_INTERVALS (buffer
), start
, length
);
1222 adjust_intervals_for_deletion (buffer
, start
, -length
);
1225 /* Merge interval I with its lexicographic successor. The resulting
1226 interval is returned, and has the properties of the original
1227 successor. The properties of I are lost. I is removed from the
1231 The caller must verify that this is not the last (rightmost)
1235 merge_interval_right (i
)
1236 register INTERVAL i
;
1238 register int absorb
= LENGTH (i
);
1239 register INTERVAL successor
;
1241 /* Zero out this interval. */
1242 i
->total_length
-= absorb
;
1244 /* Find the succeeding interval. */
1245 if (! NULL_RIGHT_CHILD (i
)) /* It's below us. Add absorb
1248 successor
= i
->right
;
1249 while (! NULL_LEFT_CHILD (successor
))
1251 successor
->total_length
+= absorb
;
1252 successor
= successor
->left
;
1255 successor
->total_length
+= absorb
;
1256 delete_interval (i
);
1261 while (! NULL_PARENT (successor
)) /* It's above us. Subtract as
1264 if (AM_LEFT_CHILD (successor
))
1266 successor
= successor
->parent
;
1267 delete_interval (i
);
1271 successor
= successor
->parent
;
1272 successor
->total_length
-= absorb
;
1275 /* This must be the rightmost or last interval and cannot
1276 be merged right. The caller should have known. */
1280 /* Merge interval I with its lexicographic predecessor. The resulting
1281 interval is returned, and has the properties of the original predecessor.
1282 The properties of I are lost. Interval node I is removed from the tree.
1285 The caller must verify that this is not the first (leftmost) interval. */
1288 merge_interval_left (i
)
1289 register INTERVAL i
;
1291 register int absorb
= LENGTH (i
);
1292 register INTERVAL predecessor
;
1294 /* Zero out this interval. */
1295 i
->total_length
-= absorb
;
1297 /* Find the preceding interval. */
1298 if (! NULL_LEFT_CHILD (i
)) /* It's below us. Go down,
1299 adding ABSORB as we go. */
1301 predecessor
= i
->left
;
1302 while (! NULL_RIGHT_CHILD (predecessor
))
1304 predecessor
->total_length
+= absorb
;
1305 predecessor
= predecessor
->right
;
1308 predecessor
->total_length
+= absorb
;
1309 delete_interval (i
);
1314 while (! NULL_PARENT (predecessor
)) /* It's above us. Go up,
1315 subtracting ABSORB. */
1317 if (AM_RIGHT_CHILD (predecessor
))
1319 predecessor
= predecessor
->parent
;
1320 delete_interval (i
);
1324 predecessor
= predecessor
->parent
;
1325 predecessor
->total_length
-= absorb
;
1328 /* This must be the leftmost or first interval and cannot
1329 be merged left. The caller should have known. */
1333 /* Make an exact copy of interval tree SOURCE which descends from
1334 PARENT. This is done by recursing through SOURCE, copying
1335 the current interval and its properties, and then adjusting
1336 the pointers of the copy. */
1339 reproduce_tree (source
, parent
)
1340 INTERVAL source
, parent
;
1342 register INTERVAL t
= make_interval ();
1344 bcopy (source
, t
, INTERVAL_SIZE
);
1345 copy_properties (source
, t
);
1347 if (! NULL_LEFT_CHILD (source
))
1348 t
->left
= reproduce_tree (source
->left
, t
);
1349 if (! NULL_RIGHT_CHILD (source
))
1350 t
->right
= reproduce_tree (source
->right
, t
);
1356 /* Nobody calls this. Perhaps it's a vestige of an earlier design. */
1358 /* Make a new interval of length LENGTH starting at START in the
1359 group of intervals INTERVALS, which is actually an interval tree.
1360 Returns the new interval.
1362 Generate an error if the new positions would overlap an existing
1366 make_new_interval (intervals
, start
, length
)
1372 slot
= find_interval (intervals
, start
);
1373 if (start
+ length
> slot
->position
+ LENGTH (slot
))
1374 error ("Interval would overlap");
1376 if (start
== slot
->position
&& length
== LENGTH (slot
))
1379 if (slot
->position
== start
)
1381 /* New right node. */
1382 split_interval_right (slot
, length
);
1386 if (slot
->position
+ LENGTH (slot
) == start
+ length
)
1388 /* New left node. */
1389 split_interval_left (slot
, LENGTH (slot
) - length
);
1393 /* Convert interval SLOT into three intervals. */
1394 split_interval_left (slot
, start
- slot
->position
);
1395 split_interval_right (slot
, length
);
1400 /* Insert the intervals of SOURCE into BUFFER at POSITION.
1401 LENGTH is the length of the text in SOURCE.
1403 This is used in insdel.c when inserting Lisp_Strings into the
1404 buffer. The text corresponding to SOURCE is already in the buffer
1405 when this is called. The intervals of new tree are a copy of those
1406 belonging to the string being inserted; intervals are never
1409 If the inserted text had no intervals associated, and we don't
1410 want to inherit the surrounding text's properties, this function
1411 simply returns -- offset_intervals should handle placing the
1412 text in the correct interval, depending on the sticky bits.
1414 If the inserted text had properties (intervals), then there are two
1415 cases -- either insertion happened in the middle of some interval,
1416 or between two intervals.
1418 If the text goes into the middle of an interval, then new
1419 intervals are created in the middle with only the properties of
1420 the new text, *unless* the macro MERGE_INSERTIONS is true, in
1421 which case the new text has the union of its properties and those
1422 of the text into which it was inserted.
1424 If the text goes between two intervals, then if neither interval
1425 had its appropriate sticky property set (front_sticky, rear_sticky),
1426 the new text has only its properties. If one of the sticky properties
1427 is set, then the new text "sticks" to that region and its properties
1428 depend on merging as above. If both the preceding and succeeding
1429 intervals to the new text are "sticky", then the new text retains
1430 only its properties, as if neither sticky property were set. Perhaps
1431 we should consider merging all three sets of properties onto the new
1435 graft_intervals_into_buffer (source
, position
, length
, buffer
, inherit
)
1437 int position
, length
;
1438 struct buffer
*buffer
;
1441 register INTERVAL under
, over
, this, prev
;
1442 register INTERVAL tree
;
1445 tree
= BUF_INTERVALS (buffer
);
1447 /* If the new text has no properties, it becomes part of whatever
1448 interval it was inserted into. */
1449 if (NULL_INTERVAL_P (source
))
1452 if (!inherit
&& ! NULL_INTERVAL_P (tree
))
1454 XSETBUFFER (buf
, buffer
);
1455 Fset_text_properties (make_number (position
),
1456 make_number (position
+ length
),
1459 if (! NULL_INTERVAL_P (BUF_INTERVALS (buffer
)))
1460 BUF_INTERVALS (buffer
) = balance_an_interval (BUF_INTERVALS (buffer
));
1464 if (NULL_INTERVAL_P (tree
))
1466 /* The inserted text constitutes the whole buffer, so
1467 simply copy over the interval structure. */
1468 if ((BUF_Z (buffer
) - BUF_BEG (buffer
)) == TOTAL_LENGTH (source
))
1471 XSETBUFFER (buf
, buffer
);
1472 BUF_INTERVALS (buffer
) = reproduce_tree (source
, buf
);
1473 /* Explicitly free the old tree here. */
1478 /* Create an interval tree in which to place a copy
1479 of the intervals of the inserted string. */
1482 XSETBUFFER (buf
, buffer
);
1483 tree
= create_root_interval (buf
);
1486 else if (TOTAL_LENGTH (tree
) == TOTAL_LENGTH (source
))
1487 /* If the buffer contains only the new string, but
1488 there was already some interval tree there, then it may be
1489 some zero length intervals. Eventually, do something clever
1490 about inserting properly. For now, just waste the old intervals. */
1492 BUF_INTERVALS (buffer
) = reproduce_tree (source
, tree
->parent
);
1493 /* Explicitly free the old tree here. */
1497 /* Paranoia -- the text has already been added, so this buffer
1498 should be of non-zero length. */
1499 else if (TOTAL_LENGTH (tree
) == 0)
1502 this = under
= find_interval (tree
, position
);
1503 if (NULL_INTERVAL_P (under
)) /* Paranoia */
1505 over
= find_interval (source
, 1);
1507 /* Here for insertion in the middle of an interval.
1508 Split off an equivalent interval to the right,
1509 then don't bother with it any more. */
1511 if (position
> under
->position
)
1513 INTERVAL end_unchanged
1514 = split_interval_left (this, position
- under
->position
);
1515 copy_properties (under
, end_unchanged
);
1516 under
->position
= position
;
1522 prev
= previous_interval (under
);
1523 if (prev
&& !END_NONSTICKY_P (prev
))
1527 /* Insertion is now at beginning of UNDER. */
1529 /* The inserted text "sticks" to the interval `under',
1530 which means it gets those properties.
1531 The properties of under are the result of
1532 adjust_intervals_for_insertion, so stickiness has
1533 already been taken care of. */
1535 while (! NULL_INTERVAL_P (over
))
1537 if (LENGTH (over
) < LENGTH (under
))
1539 this = split_interval_left (under
, LENGTH (over
));
1540 copy_properties (under
, this);
1544 copy_properties (over
, this);
1546 merge_properties (over
, this);
1548 copy_properties (over
, this);
1549 over
= next_interval (over
);
1552 if (! NULL_INTERVAL_P (BUF_INTERVALS (buffer
)))
1553 BUF_INTERVALS (buffer
) = balance_an_interval (BUF_INTERVALS (buffer
));
1557 /* Get the value of property PROP from PLIST,
1558 which is the plist of an interval.
1559 We check for direct properties, for categories with property PROP,
1560 and for PROP appearing on the default-text-properties list. */
1563 textget (plist
, prop
)
1565 register Lisp_Object prop
;
1567 register Lisp_Object tail
, fallback
;
1570 for (tail
= plist
; !NILP (tail
); tail
= Fcdr (Fcdr (tail
)))
1572 register Lisp_Object tem
;
1575 return Fcar (Fcdr (tail
));
1576 if (EQ (tem
, Qcategory
))
1578 tem
= Fcar (Fcdr (tail
));
1580 fallback
= Fget (tem
, prop
);
1584 if (! NILP (fallback
))
1586 if (CONSP (Vdefault_text_properties
))
1587 return Fplist_get (Vdefault_text_properties
, prop
);
1592 /* Set point in BUFFER to POSITION. If the target position is
1593 before an intangible character, move to an ok place. */
1596 set_point (position
, buffer
)
1597 register int position
;
1598 register struct buffer
*buffer
;
1600 register INTERVAL to
, from
, toprev
, fromprev
, target
;
1602 register Lisp_Object obj
;
1603 int old_position
= BUF_PT (buffer
);
1604 int backwards
= (position
< old_position
? 1 : 0);
1606 int original_position
;
1608 buffer
->point_before_scroll
= Qnil
;
1610 if (position
== BUF_PT (buffer
))
1613 /* Check this now, before checking if the buffer has any intervals.
1614 That way, we can catch conditions which break this sanity check
1615 whether or not there are intervals in the buffer. */
1616 if (position
> BUF_ZV (buffer
) || position
< BUF_BEGV (buffer
))
1619 have_overlays
= (! NILP (buffer
->overlays_before
)
1620 || ! NILP (buffer
->overlays_after
));
1622 /* If we have no text properties and overlays,
1623 then we can do it quickly. */
1624 if (NULL_INTERVAL_P (BUF_INTERVALS (buffer
)) && ! have_overlays
)
1626 BUF_PT (buffer
) = position
;
1630 /* Set TO to the interval containing the char after POSITION,
1631 and TOPREV to the interval containing the char before POSITION.
1632 Either one may be null. They may be equal. */
1633 to
= find_interval (BUF_INTERVALS (buffer
), position
);
1634 if (position
== BUF_BEGV (buffer
))
1636 else if (to
&& to
->position
== position
)
1637 toprev
= previous_interval (to
);
1641 buffer_point
= (BUF_PT (buffer
) == BUF_ZV (buffer
)
1642 ? BUF_ZV (buffer
) - 1
1645 /* Set FROM to the interval containing the char after PT,
1646 and FROMPREV to the interval containing the char before PT.
1647 Either one may be null. They may be equal. */
1648 /* We could cache this and save time. */
1649 from
= find_interval (BUF_INTERVALS (buffer
), buffer_point
);
1650 if (buffer_point
== BUF_BEGV (buffer
))
1652 else if (from
&& from
->position
== BUF_PT (buffer
))
1653 fromprev
= previous_interval (from
);
1654 else if (buffer_point
!= BUF_PT (buffer
))
1655 fromprev
= from
, from
= 0;
1659 /* Moving within an interval. */
1660 if (to
== from
&& toprev
== fromprev
&& INTERVAL_VISIBLE_P (to
)
1663 BUF_PT (buffer
) = position
;
1667 original_position
= position
;
1669 /* If the new position is between two intangible characters
1670 with the same intangible property value,
1671 move forward or backward until a change in that property. */
1672 if (NILP (Vinhibit_point_motion_hooks
)
1673 && ((! NULL_INTERVAL_P (to
) && ! NULL_INTERVAL_P (toprev
))
1675 /* Intangibility never stops us from positioning at the beginning
1676 or end of the buffer, so don't bother checking in that case. */
1677 && position
!= BEGV
&& position
!= ZV
)
1679 Lisp_Object intangible_propval
;
1682 XSETINT (pos
, position
);
1686 intangible_propval
= Fget_char_property (make_number (position
),
1689 /* If following char is intangible,
1690 skip back over all chars with matching intangible property. */
1691 if (! NILP (intangible_propval
))
1692 while (XINT (pos
) > BUF_BEGV (buffer
)
1693 && EQ (Fget_char_property (make_number (XINT (pos
) - 1),
1695 intangible_propval
))
1696 pos
= Fprevious_char_property_change (pos
, Qnil
);
1700 intangible_propval
= Fget_char_property (make_number (position
- 1),
1703 /* If following char is intangible,
1704 skip back over all chars with matching intangible property. */
1705 if (! NILP (intangible_propval
))
1706 while (XINT (pos
) < BUF_ZV (buffer
)
1707 && EQ (Fget_char_property (pos
, Qintangible
, Qnil
),
1708 intangible_propval
))
1709 pos
= Fnext_char_property_change (pos
, Qnil
);
1713 position
= XINT (pos
);
1716 if (position
!= original_position
)
1718 /* Set TO to the interval containing the char after POSITION,
1719 and TOPREV to the interval containing the char before POSITION.
1720 Either one may be null. They may be equal. */
1721 to
= find_interval (BUF_INTERVALS (buffer
), position
);
1722 if (position
== BUF_BEGV (buffer
))
1724 else if (to
&& to
->position
== position
)
1725 toprev
= previous_interval (to
);
1730 /* Here TO is the interval after the stopping point
1731 and TOPREV is the interval before the stopping point.
1732 One or the other may be null. */
1734 BUF_PT (buffer
) = position
;
1736 /* We run point-left and point-entered hooks here, iff the
1737 two intervals are not equivalent. These hooks take
1738 (old_point, new_point) as arguments. */
1739 if (NILP (Vinhibit_point_motion_hooks
)
1740 && (! intervals_equal (from
, to
)
1741 || ! intervals_equal (fromprev
, toprev
)))
1743 Lisp_Object leave_after
, leave_before
, enter_after
, enter_before
;
1746 leave_after
= textget (fromprev
->plist
, Qpoint_left
);
1750 leave_before
= textget (from
->plist
, Qpoint_left
);
1752 leave_before
= Qnil
;
1755 enter_after
= textget (toprev
->plist
, Qpoint_entered
);
1759 enter_before
= textget (to
->plist
, Qpoint_entered
);
1761 enter_before
= Qnil
;
1763 if (! EQ (leave_before
, enter_before
) && !NILP (leave_before
))
1764 call2 (leave_before
, old_position
, position
);
1765 if (! EQ (leave_after
, enter_after
) && !NILP (leave_after
))
1766 call2 (leave_after
, old_position
, position
);
1768 if (! EQ (enter_before
, leave_before
) && !NILP (enter_before
))
1769 call2 (enter_before
, old_position
, position
);
1770 if (! EQ (enter_after
, leave_after
) && !NILP (enter_after
))
1771 call2 (enter_after
, old_position
, position
);
1775 /* Set point temporarily, without checking any text properties. */
1778 temp_set_point (position
, buffer
)
1780 struct buffer
*buffer
;
1782 BUF_PT (buffer
) = position
;
1785 /* Return the proper local map for position POSITION in BUFFER.
1786 Use the map specified by the local-map property, if any.
1787 Otherwise, use BUFFER's local map. */
1790 get_local_map (position
, buffer
)
1791 register int position
;
1792 register struct buffer
*buffer
;
1794 Lisp_Object prop
, tem
, lispy_position
, lispy_buffer
;
1795 int old_begv
, old_zv
;
1797 /* Perhaps we should just change `position' to the limit. */
1798 if (position
> BUF_Z (buffer
) || position
< BUF_BEG (buffer
))
1801 /* Ignore narrowing, so that a local map continues to be valid even if
1802 the visible region contains no characters and hence no properties. */
1803 old_begv
= BUF_BEGV (buffer
);
1804 old_zv
= BUF_ZV (buffer
);
1805 BUF_BEGV (buffer
) = BUF_BEG (buffer
);
1806 BUF_ZV (buffer
) = BUF_Z (buffer
);
1808 /* There are no properties at the end of the buffer, so in that case
1809 check for a local map on the last character of the buffer instead. */
1810 if (position
== BUF_Z (buffer
) && BUF_Z (buffer
) > BUF_BEG (buffer
))
1812 XSETFASTINT (lispy_position
, position
);
1813 XSETBUFFER (lispy_buffer
, buffer
);
1814 prop
= Fget_char_property (lispy_position
, Qlocal_map
, lispy_buffer
);
1816 BUF_BEGV (buffer
) = old_begv
;
1817 BUF_ZV (buffer
) = old_zv
;
1819 /* Use the local map only if it is valid. */
1820 /* Do allow symbols that are defined as keymaps. */
1821 if (SYMBOLP (prop
) && !NILP (prop
))
1822 prop
= Findirect_function (prop
);
1824 && (tem
= Fkeymapp (prop
), !NILP (tem
)))
1827 return buffer
->keymap
;
1830 /* Produce an interval tree reflecting the intervals in
1831 TREE from START to START + LENGTH. */
1834 copy_intervals (tree
, start
, length
)
1838 register INTERVAL i
, new, t
;
1839 register int got
, prevlen
;
1841 if (NULL_INTERVAL_P (tree
) || length
<= 0)
1842 return NULL_INTERVAL
;
1844 i
= find_interval (tree
, start
);
1845 if (NULL_INTERVAL_P (i
) || LENGTH (i
) == 0)
1848 /* If there is only one interval and it's the default, return nil. */
1849 if ((start
- i
->position
+ 1 + length
) < LENGTH (i
)
1850 && DEFAULT_INTERVAL_P (i
))
1851 return NULL_INTERVAL
;
1853 new = make_interval ();
1855 got
= (LENGTH (i
) - (start
- i
->position
));
1856 new->total_length
= length
;
1857 copy_properties (i
, new);
1861 while (got
< length
)
1863 i
= next_interval (i
);
1864 t
= split_interval_right (t
, prevlen
);
1865 copy_properties (i
, t
);
1866 prevlen
= LENGTH (i
);
1870 return balance_an_interval (new);
1873 /* Give STRING the properties of BUFFER from POSITION to LENGTH. */
1876 copy_intervals_to_string (string
, buffer
, position
, length
)
1878 struct buffer
*buffer
;
1879 int position
, length
;
1881 INTERVAL interval_copy
= copy_intervals (BUF_INTERVALS (buffer
),
1883 if (NULL_INTERVAL_P (interval_copy
))
1886 interval_copy
->parent
= (INTERVAL
) string
;
1887 XSTRING (string
)->intervals
= interval_copy
;
1890 /* Return 1 if string S1 and S2 have identical properties; 0 otherwise.
1891 Assume they have identical characters. */
1894 compare_string_intervals (s1
, s2
)
1899 int end
= XSTRING (s1
)->size
+ 1;
1901 /* We specify 1 as position because the interval functions
1902 always use positions starting at 1. */
1903 i1
= find_interval (XSTRING (s1
)->intervals
, 1);
1904 i2
= find_interval (XSTRING (s2
)->intervals
, 1);
1908 /* Determine how far we can go before we reach the end of I1 or I2. */
1909 int len1
= (i1
!= 0 ? INTERVAL_LAST_POS (i1
) : end
) - pos
;
1910 int len2
= (i2
!= 0 ? INTERVAL_LAST_POS (i2
) : end
) - pos
;
1911 int distance
= min (len1
, len2
);
1913 /* If we ever find a mismatch between the strings,
1915 if (! intervals_equal (i1
, i2
))
1918 /* Advance POS till the end of the shorter interval,
1919 and advance one or both interval pointers for the new position. */
1921 if (len1
== distance
)
1922 i1
= next_interval (i1
);
1923 if (len2
== distance
)
1924 i2
= next_interval (i2
);
1929 #endif /* USE_TEXT_PROPERTIES */