/* Code for doing intervals. Copyright (C) 1993, 1994, 1995 Free Software Foundation, Inc. This file is part of GNU Emacs. GNU Emacs is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. 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 along with GNU Emacs; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* 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. */ #include #include "lisp.h" #include "intervals.h" #include "buffer.h" #include "puresize.h" #include "keyboard.h" /* The rest of the file is within this conditional. */ #ifdef USE_TEXT_PROPERTIES /* 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)) #define min(x, y) ((x) < (y) ? (x) : (y)) Lisp_Object merge_properties_sticky (); /* Utility functions for intervals. */ /* Create the root interval of some object, a buffer or string. */ INTERVAL create_root_interval (parent) Lisp_Object parent; { INTERVAL new; CHECK_IMPURE (parent); new = make_interval (); if (BUFFERP (parent)) { new->total_length = (BUF_Z (XBUFFER (parent)) - BUF_BEG (XBUFFER (parent))); BUF_INTERVALS (XBUFFER (parent)) = new; } else if (STRINGP (parent)) { new->total_length = XSTRING (parent)->size; XSTRING (parent)->intervals = new; } new->parent = (INTERVAL) parent; new->position = 1; return new; } /* Make the interval TARGET have exactly the properties of SOURCE */ void copy_properties (source, target) register INTERVAL source, target; { 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 of interval TARGET. That is to say, each property in SOURCE is added to TARGET if TARGET has no such property as yet. */ static void merge_properties (source, target) register INTERVAL source, target; { register Lisp_Object o, sym, val; if (DEFAULT_INTERVAL_P (source) && DEFAULT_INTERVAL_P (target)) return; MERGE_INTERVAL_CACHE (source, target); o = source->plist; while (! EQ (o, Qnil)) { sym = Fcar (o); val = Fmemq (sym, target->plist); if (NILP (val)) { o = Fcdr (o); val = Fcar (o); target->plist = Fcons (sym, Fcons (val, target->plist)); o = Fcdr (o); } else o = Fcdr (Fcdr (o)); } } /* Return 1 if the two intervals have the same properties, 0 otherwise. */ int intervals_equal (i0, i1) INTERVAL i0, i1; { register Lisp_Object i0_cdr, i0_sym, i1_val; register i1_len; if (DEFAULT_INTERVAL_P (i0) && DEFAULT_INTERVAL_P (i1)) return 1; if (DEFAULT_INTERVAL_P (i0) || DEFAULT_INTERVAL_P (i1)) return 0; i1_len = XFASTINT (Flength (i1->plist)); if (i1_len & 0x1) /* Paranoia -- plists are always even */ abort (); i1_len /= 2; i0_cdr = i0->plist; while (!NILP (i0_cdr)) { /* Lengths of the two plists were unequal. */ if (i1_len == 0) return 0; i0_sym = Fcar (i0_cdr); i1_val = Fmemq (i0_sym, i1->plist); /* i0 has something i1 doesn't. */ if (EQ (i1_val, Qnil)) return 0; /* i0 and i1 both have sym, but it has different values in each. */ i0_cdr = Fcdr (i0_cdr); if (! EQ (Fcar (Fcdr (i1_val)), Fcar (i0_cdr))) return 0; i0_cdr = Fcdr (i0_cdr); i1_len--; } /* Lengths of the two plists were unequal. */ if (i1_len > 0) return 0; return 1; } static int icount; static int idepth; static int zero_length; /* Traverse an interval tree TREE, performing FUNCTION on each node. Pass FUNCTION two args: an interval, and ARG. */ void traverse_intervals (tree, position, depth, function, arg) INTERVAL tree; int position, depth; void (* function) (); Lisp_Object arg; { if (NULL_INTERVAL_P (tree)) return; traverse_intervals (tree->left, position, depth + 1, function, arg); position += LEFT_TOTAL_LENGTH (tree); tree->position = position; (*function) (tree, arg); position += LENGTH (tree); traverse_intervals (tree->right, position, depth + 1, function, arg); } #if 0 /* These functions are temporary, for debugging purposes only. */ 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; traverse_intervals (tree, 1, 0, &check_for_interval, Qnil); 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; traverse_intervals (i, 1, 0, &inc_interval_count, Qnil); return icount; } static INTERVAL root_interval (interval) INTERVAL interval; { register INTERVAL i = interval; while (! ROOT_INTERVAL_P (i)) i = i->parent; return i; } #endif /* Assuming that a left child exists, perform the following operation: A B / \ / \ B => A / \ / \ c c */ static INTERVAL rotate_right (interval) INTERVAL interval; { INTERVAL i; INTERVAL B = interval->left; int old_total = interval->total_length; /* Deal with any Parent of A; make it point to B. */ if (! ROOT_INTERVAL_P (interval)) if (AM_LEFT_CHILD (interval)) interval->parent->left = B; else interval->parent->right = B; B->parent = interval->parent; /* Make B the parent of A */ i = B->right; B->right = interval; interval->parent = B; /* Make A point to c */ interval->left = i; if (! NULL_INTERVAL_P (i)) i->parent = interval; /* A's total length is decreased by the length of B and its left child. */ interval->total_length -= B->total_length - LEFT_TOTAL_LENGTH (interval); /* B must have the same total length of A. */ B->total_length = old_total; return B; } /* Assuming that a right child exists, perform the following operation: A B / \ / \ B => A / \ / \ c c */ static INTERVAL rotate_left (interval) INTERVAL interval; { INTERVAL i; INTERVAL B = interval->right; int old_total = interval->total_length; /* Deal with any parent of A; make it point to B. */ if (! ROOT_INTERVAL_P (interval)) if (AM_LEFT_CHILD (interval)) interval->parent->left = B; else interval->parent->right = B; B->parent = interval->parent; /* Make B the parent of A */ i = B->left; B->left = interval; interval->parent = B; /* Make A point to c */ interval->right = i; if (! NULL_INTERVAL_P (i)) i->parent = interval; /* A's total length is decreased by the length of B and its right child. */ interval->total_length -= B->total_length - RIGHT_TOTAL_LENGTH (interval); /* B must have the same total length of A. */ B->total_length = old_total; return B; } /* Balance an interval tree with the assumption that the subtrees themselves are already balanced. */ static INTERVAL balance_an_interval (i) INTERVAL i; { register int old_diff, new_diff; while (1) { old_diff = LEFT_TOTAL_LENGTH (i) - RIGHT_TOTAL_LENGTH (i); if (old_diff > 0) { new_diff = i->total_length - i->left->total_length + RIGHT_TOTAL_LENGTH (i->left) - LEFT_TOTAL_LENGTH (i->left); if (abs (new_diff) >= old_diff) break; i = rotate_right (i); balance_an_interval (i->right); } else if (old_diff < 0) { new_diff = i->total_length - i->right->total_length + LEFT_TOTAL_LENGTH (i->right) - RIGHT_TOTAL_LENGTH (i->right); if (abs (new_diff) >= -old_diff) 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. */ static INLINE INTERVAL balance_possible_root_interval (interval) register INTERVAL interval; { Lisp_Object parent; if (interval->parent == NULL_INTERVAL) return interval; parent = (Lisp_Object) (interval->parent); interval = balance_an_interval (interval); if (BUFFERP (parent)) BUF_INTERVALS (XBUFFER (parent)) = interval; else if (STRINGP (parent)) XSTRING (parent)->intervals = interval; return interval; } /* Balance the interval tree TREE. Balancing is by weight (the amount of text). */ static INTERVAL balance_intervals_internal (tree) register INTERVAL tree; { /* Balance within each side. */ if (tree->left) balance_intervals_internal (tree->left); if (tree->right) balance_intervals_internal (tree->right); return balance_an_interval (tree); } /* Advertised interface to balance intervals. */ INTERVAL balance_intervals (tree) INTERVAL tree; { if (tree == NULL_INTERVAL) return NULL_INTERVAL; return balance_intervals_internal (tree); } /* 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. 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, it is still a root after this operation. */ INTERVAL split_interval_right (interval, offset) INTERVAL interval; int offset; { INTERVAL new = make_interval (); int position = interval->position; int new_length = LENGTH (interval) - offset; new->position = position + offset; new->parent = interval; if (NULL_RIGHT_CHILD (interval)) { interval->right = new; new->total_length = new_length; return new; } /* Insert the new node between INTERVAL and its right child. */ new->right = interval->right; interval->right->parent = new; interval->right = new; new->total_length = new_length + new->right->total_length; balance_an_interval (new); balance_possible_root_interval (interval); return new; } /* 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. 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, it is still a root after this operation. */ INTERVAL split_interval_left (interval, offset) INTERVAL interval; int offset; { INTERVAL new = make_interval (); int position = interval->position; int new_length = offset; new->position = interval->position; interval->position = interval->position + offset; new->parent = interval; if (NULL_LEFT_CHILD (interval)) { interval->left = new; new->total_length = new_length; return new; } /* Insert the new node between INTERVAL and its left child. */ new->left = interval->left; new->left->parent = new; interval->left = new; new->total_length = new_length + new->left->total_length; balance_an_interval (new); balance_possible_root_interval (interval); return new; } /* Find the interval containing text position POSITION in the text represented by the interval tree TREE. POSITION is a buffer position; the earliest position is 1. If POSITION is at the end of the buffer, return the interval containing the last character. The `position' field, which is a cache of an interval's position, is updated in the interval found. Other functions (e.g., next_interval) will update this cache based on the result of find_interval. */ INLINE INTERVAL find_interval (tree, position) register INTERVAL tree; register int position; { /* The distance from the left edge of the subtree at TREE to POSITION. */ register int relative_position = position - BEG; if (NULL_INTERVAL_P (tree)) return NULL_INTERVAL; if (relative_position > TOTAL_LENGTH (tree)) abort (); /* Paranoia */ tree = balance_possible_root_interval (tree); while (1) { if (relative_position < LEFT_TOTAL_LENGTH (tree)) { tree = tree->left; } else if (! NULL_RIGHT_CHILD (tree) && relative_position >= (TOTAL_LENGTH (tree) - RIGHT_TOTAL_LENGTH (tree))) { relative_position -= (TOTAL_LENGTH (tree) - RIGHT_TOTAL_LENGTH (tree)); tree = tree->right; } else { tree->position = (position - relative_position /* the left edge of *tree */ + LEFT_TOTAL_LENGTH (tree)); /* the left edge of this interval */ return tree; } } } /* Find the succeeding interval (lexicographically) to INTERVAL. Sets the `position' field based on that of INTERVAL (see find_interval). */ INTERVAL next_interval (interval) register INTERVAL interval; { register INTERVAL i = interval; register int next_position; 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)) { i = i->parent; i->position = next_position; return i; } i = i->parent; } return NULL_INTERVAL; } /* Find the preceding interval (lexicographically) to INTERVAL. Sets the `position' field based on that of INTERVAL (see find_interval). */ INTERVAL previous_interval (interval) register INTERVAL interval; { register INTERVAL i; register position_of_previous; 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)) { i = i->parent; i->position = interval->position - LENGTH (i); return i; } i = i->parent; } return NULL_INTERVAL; } #if 0 /* 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 and check the hungry bits of both. Then add the length going back up to the root. */ static INTERVAL adjust_intervals_for_insertion (tree, position, length) INTERVAL tree; int position, length; { register int relative_position; 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; 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; this = this->right; } else { /* If we are to use zero-length intervals as buffer pointers, then this code will have to change. */ this->total_length += length; this->position = LEFT_TOTAL_LENGTH (this) + position - relative_position + 1; return tree; } } } #endif /* Effect an adjustment corresponding to the addition of LENGTH characters of text. Do this by finding the interval containing POSITION in the interval tree TREE, and then adjusting all of its ancestors by adding 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". If both intervals are "sticky", then make them belong to the left-most interval. Another possibility would be to create a new interval for this text, and make it have the merged properties of both ends. */ static INTERVAL adjust_intervals_for_insertion (tree, position, length) INTERVAL tree; int position, length; { register INTERVAL i; register INTERVAL temp; int eobp = 0; if (TOTAL_LENGTH (tree) == 0) /* Paranoia */ abort (); /* If inserting at point-max of a buffer, that position will be out of range. Remember that buffer positions are 1-based. */ if (position >= BEG + TOTAL_LENGTH (tree)){ position = BEG + TOTAL_LENGTH (tree); eobp = 1; } i = find_interval (tree, position); /* If in middle of an interval which is not sticky either way, we must not just give its properties to the insertion. So split this interval at the insertion point. */ if (! (position == i->position || eobp) && END_NONSTICKY_P (i) && ! FRONT_STICKY_P (i)) { temp = split_interval_right (i, position - i->position); copy_properties (i, temp); i = temp; } /* If we are positioned between intervals, check the stickiness of both of them. We have to do this too, if we are at BEG or Z. */ if (position == i->position || eobp) { register INTERVAL prev; if (position == BEG) prev = 0; else if (eobp) { prev = i; i = 0; } else prev = previous_interval (i); /* Even if we are positioned between intervals, we default to the left one if it exists. We extend it now and split off a part later, if stickiness demands it. */ for (temp = prev ? prev : i;! NULL_INTERVAL_P (temp); temp = temp->parent) { temp->total_length += length; temp = balance_possible_root_interval (temp); } /* If at least one interval has sticky properties, we check the stickiness property by property. */ if (END_NONSTICKY_P (prev) || FRONT_STICKY_P (i)) { Lisp_Object pleft, pright; struct interval newi; pleft = NULL_INTERVAL_P (prev) ? Qnil : prev->plist; pright = NULL_INTERVAL_P (i) ? Qnil : i->plist; newi.plist = merge_properties_sticky (pleft, pright); if(! prev) /* i.e. position == BEG */ { if (! intervals_equal (i, &newi)) { i = split_interval_left (i, length); i->plist = newi.plist; } } else if (! intervals_equal (prev, &newi)) { prev = split_interval_right (prev, position - prev->position); prev->plist = newi.plist; if (! NULL_INTERVAL_P (i) && intervals_equal (prev, i)) merge_interval_right (prev); } /* We will need to update the cache here later. */ } else if (! prev && ! NILP (i->plist)) { /* Just split off a new interval at the left. Since I wasn't front-sticky, the empty plist is ok. */ i = split_interval_left (i, length); } } /* Otherwise just extend the interval. */ else { for (temp = i; ! NULL_INTERVAL_P (temp); temp = temp->parent) { temp->total_length += length; temp = balance_possible_root_interval (temp); } } return tree; } /* Any property might be front-sticky on the left, rear-sticky on the left, front-sticky on the right, or rear-sticky on the right; the 16 combinations can be arranged in a matrix with rows denoting the left conditions and columns denoting the right conditions: _ __ _ _ FR FR FR FR FR__ 0 1 2 3 _FR 4 5 6 7 FR 8 9 A B FR C D E F left-props = '(front-sticky (p8 p9 pa pb pc pd pe pf) rear-nonsticky (p4 p5 p6 p7 p8 p9 pa pb) p0 L p1 L p2 L p3 L p4 L p5 L p6 L p7 L p8 L p9 L pa L pb L pc L pd L pe L pf L) right-props = '(front-sticky (p2 p3 p6 p7 pa pb pe pf) rear-nonsticky (p1 p2 p5 p6 p9 pa pd pe) p0 R p1 R p2 R p3 R p4 R p5 R p6 R p7 R p8 R p9 R pa R pb R pc R pd R pe R pf R) We inherit from whoever has a sticky side facing us. If both sides do (cases 2, 3, E, and F), then we inherit from whichever side has a non-nil value for the current property. If both sides do, then we take from the left. When we inherit a property, we get its stickiness as well as its value. So, when we merge the above two lists, we expect to get this: result = '(front-sticky (p6 p7 pa pb pc pd pe pf) rear-nonsticky (p6 pa) p0 L p1 L p2 L p3 L p6 R p7 R pa R pb R pc L pd L pe L pf L) The optimizable special cases are: left rear-nonsticky = nil, right front-sticky = nil (inherit left) left rear-nonsticky = t, right front-sticky = t (inherit right) left rear-nonsticky = t, right front-sticky = nil (inherit none) */ Lisp_Object merge_properties_sticky (pleft, pright) Lisp_Object pleft, pright; { register Lisp_Object props, front, rear; Lisp_Object lfront, lrear, rfront, rrear; register Lisp_Object tail1, tail2, sym, lval, rval; int use_left, use_right; props = Qnil; front = Qnil; rear = Qnil; lfront = textget (pleft, Qfront_sticky); lrear = textget (pleft, Qrear_nonsticky); rfront = textget (pright, Qfront_sticky); rrear = textget (pright, Qrear_nonsticky); /* Go through each element of PRIGHT. */ for (tail1 = pright; ! NILP (tail1); tail1 = Fcdr (Fcdr (tail1))) { sym = Fcar (tail1); /* Sticky properties get special treatment. */ if (EQ (sym, Qrear_nonsticky) || EQ (sym, Qfront_sticky)) continue; rval = Fcar (Fcdr (tail1)); for (tail2 = pleft; ! NILP (tail2); tail2 = Fcdr (Fcdr (tail2))) if (EQ (sym, Fcar (tail2))) break; lval = (NILP (tail2) ? Qnil : Fcar( Fcdr (tail2))); use_left = ! TMEM (sym, lrear); use_right = TMEM (sym, rfront); if (use_left && use_right) { use_left = ! NILP (lval); use_right = ! NILP (rval); } if (use_left) { /* We build props as (value sym ...) rather than (sym value ...) because we plan to nreverse it when we're done. */ if (! NILP (lval)) props = Fcons (lval, Fcons (sym, props)); if (TMEM (sym, lfront)) front = Fcons (sym, front); if (TMEM (sym, lrear)) rear = Fcons (sym, rear); } else if (use_right) { if (! NILP (rval)) props = Fcons (rval, Fcons (sym, props)); if (TMEM (sym, rfront)) front = Fcons (sym, front); if (TMEM (sym, rrear)) rear = Fcons (sym, rear); } } /* Now go through each element of PLEFT. */ for (tail2 = pleft; ! NILP (tail2); tail2 = Fcdr (Fcdr (tail2))) { sym = Fcar (tail2); /* Sticky properties get special treatment. */ if (EQ (sym, Qrear_nonsticky) || EQ (sym, Qfront_sticky)) continue; /* If sym is in PRIGHT, we've already considered it. */ for (tail1 = pright; ! NILP (tail1); tail1 = Fcdr (Fcdr (tail1))) if (EQ (sym, Fcar (tail1))) break; if (! NILP (tail1)) continue; lval = Fcar (Fcdr (tail2)); /* Since rval is known to be nil in this loop, the test simplifies. */ if (! TMEM (sym, lrear)) { if (! NILP (lval)) props = Fcons (lval, Fcons (sym, props)); if (TMEM (sym, lfront)) front = Fcons (sym, front); } else if (TMEM (sym, rfront)) { /* The value is nil, but we still inherit the stickiness from the right. */ front = Fcons (sym, front); if (TMEM (sym, rrear)) rear = Fcons (sym, rear); } } props = Fnreverse (props); if (! NILP (rear)) props = Fcons (Qrear_nonsticky, Fcons (Fnreverse (rear), props)); if (! NILP (front)) props = Fcons (Qfront_sticky, Fcons (Fnreverse (front), props)); return props; } /* Delete an node I from its interval tree by merging its subtrees into one subtree which is then returned. Caller is responsible for storing the resulting subtree into its parent. */ static INTERVAL delete_node (i) register INTERVAL i; { register INTERVAL migrate, this; register int migrate_amt; if (NULL_INTERVAL_P (i->left)) return i->right; if (NULL_INTERVAL_P (i->right)) return i->left; migrate = i->left; migrate_amt = i->left->total_length; this = i->right; this->total_length += migrate_amt; while (! NULL_INTERVAL_P (this->left)) { this = this->left; this->total_length += migrate_amt; } this->left = migrate; migrate->parent = this; return i->right; } /* Delete interval I from its tree by calling `delete_node' and properly connecting the resultant subtree. I is presumed to be empty; that is, no adjustments are made for the length of I. */ void delete_interval (i) register INTERVAL i; { register INTERVAL parent; int amt = LENGTH (i); if (amt > 0) /* Only used on zero-length intervals now. */ abort (); if (ROOT_INTERVAL_P (i)) { Lisp_Object owner; owner = (Lisp_Object) i->parent; parent = delete_node (i); if (! NULL_INTERVAL_P (parent)) parent->parent = (INTERVAL) owner; if (BUFFERP (owner)) BUF_INTERVALS (XBUFFER (owner)) = parent; else if (STRINGP (owner)) XSTRING (owner)->intervals = parent; else abort (); return; } parent = i->parent; if (AM_LEFT_CHILD (i)) { parent->left = delete_node (i); if (! NULL_INTERVAL_P (parent->left)) parent->left->parent = parent; } else { parent->right = delete_node (i); if (! NULL_INTERVAL_P (parent->right)) parent->right->parent = parent; } } /* Find the interval in TREE corresponding to the relative position FROM and delete as much as possible of AMOUNT from that interval. Return the amount actually deleted, and if the interval was zeroed-out, delete that interval node from the tree. Note that FROM is actually origin zero, aka relative to the leftmost edge of tree. This is appropriate since we call ourselves recursively on subtrees. Do this by recursing down TREE to the interval in question, and deleting the appropriate amount of text. */ static int interval_deletion_adjustment (tree, from, amount) register INTERVAL tree; register int from, amount; { register int relative_position = from; if (NULL_INTERVAL_P (tree)) return 0; /* Left branch */ if (relative_position < LEFT_TOTAL_LENGTH (tree)) { int subtract = interval_deletion_adjustment (tree->left, relative_position, amount); tree->total_length -= subtract; return subtract; } /* Right branch */ else if (relative_position >= (TOTAL_LENGTH (tree) - RIGHT_TOTAL_LENGTH (tree))) { int subtract; relative_position -= (tree->total_length - RIGHT_TOTAL_LENGTH (tree)); subtract = interval_deletion_adjustment (tree->right, relative_position, amount); tree->total_length -= subtract; return subtract; } /* Here -- this node. */ else { /* How much can we delete from this interval? */ int my_amount = ((tree->total_length - RIGHT_TOTAL_LENGTH (tree)) - relative_position); if (amount > my_amount) amount = my_amount; tree->total_length -= amount; if (LENGTH (tree) == 0) delete_interval (tree); return amount; } /* Never reach here. */ } /* Effect the adjustments necessary to the interval tree of BUFFER to correspond to the deletion of LENGTH characters from that buffer text. The deletion is effected at position START (which is a buffer position, i.e. origin 1). */ static void adjust_intervals_for_deletion (buffer, start, length) struct buffer *buffer; int start, length; { register int left_to_delete = length; register INTERVAL tree = BUF_INTERVALS (buffer); register int deleted; if (NULL_INTERVAL_P (tree)) return; if (start > BEG + TOTAL_LENGTH (tree) || start + length > BEG + TOTAL_LENGTH (tree)) abort (); if (length == TOTAL_LENGTH (tree)) { BUF_INTERVALS (buffer) = NULL_INTERVAL; return; } if (ONLY_INTERVAL_P (tree)) { tree->total_length -= length; return; } if (start > BEG + TOTAL_LENGTH (tree)) start = BEG + TOTAL_LENGTH (tree); while (left_to_delete > 0) { left_to_delete -= interval_deletion_adjustment (tree, start - 1, left_to_delete); tree = BUF_INTERVALS (buffer); if (left_to_delete == tree->total_length) { BUF_INTERVALS (buffer) = NULL_INTERVAL; return; } } } /* Make the adjustments necessary to the interval tree of BUFFER to represent an addition or deletion of LENGTH characters starting at position START. Addition or deletion is indicated by the sign of LENGTH. */ INLINE void offset_intervals (buffer, start, length) struct buffer *buffer; int start, length; { if (NULL_INTERVAL_P (BUF_INTERVALS (buffer)) || length == 0) return; if (length > 0) adjust_intervals_for_insertion (BUF_INTERVALS (buffer), start, length); else adjust_intervals_for_deletion (buffer, start, -length); } /* Merge interval I with its lexicographic successor. The resulting interval is returned, and has the properties of the original successor. The properties of I are lost. I is removed from the interval tree. IMPORTANT: The caller must verify that this is not the last (rightmost) interval. */ INTERVAL merge_interval_right (i) register INTERVAL i; { register int absorb = LENGTH (i); register INTERVAL successor; /* Zero out this interval. */ i->total_length -= absorb; /* Find the succeeding interval. */ if (! NULL_RIGHT_CHILD (i)) /* It's below us. Add absorb as we descend. */ { successor = i->right; while (! NULL_LEFT_CHILD (successor)) { successor->total_length += absorb; successor = successor->left; } successor->total_length += absorb; delete_interval (i); return successor; } successor = i; while (! NULL_PARENT (successor)) /* It's above us. Subtract as we ascend. */ { if (AM_LEFT_CHILD (successor)) { successor = successor->parent; delete_interval (i); return successor; } successor = successor->parent; successor->total_length -= absorb; } /* This must be the rightmost or last interval and cannot be merged right. The caller should have known. */ abort (); } /* Merge interval I with its lexicographic predecessor. The resulting interval is returned, and has the properties of the original predecessor. The properties of I are lost. Interval node I is removed from the tree. IMPORTANT: The caller must verify that this is not the first (leftmost) interval. */ INTERVAL merge_interval_left (i) register INTERVAL i; { register int absorb = LENGTH (i); register INTERVAL predecessor; /* Zero out this interval. */ i->total_length -= absorb; /* Find the preceding interval. */ if (! NULL_LEFT_CHILD (i)) /* It's below us. Go down, adding ABSORB as we go. */ { predecessor = i->left; while (! NULL_RIGHT_CHILD (predecessor)) { predecessor->total_length += absorb; predecessor = predecessor->right; } predecessor->total_length += absorb; delete_interval (i); return predecessor; } predecessor = i; while (! NULL_PARENT (predecessor)) /* It's above us. Go up, subtracting ABSORB. */ { if (AM_RIGHT_CHILD (predecessor)) { predecessor = predecessor->parent; delete_interval (i); return predecessor; } predecessor = predecessor->parent; predecessor->total_length -= absorb; } /* This must be the leftmost or first interval and cannot be merged left. The caller should have known. */ abort (); } /* Make an exact copy of interval tree SOURCE which descends from PARENT. This is done by recursing through SOURCE, copying the current interval and its properties, and then adjusting the pointers of the copy. */ static INTERVAL reproduce_tree (source, parent) INTERVAL source, parent; { register INTERVAL t = make_interval (); bcopy (source, t, INTERVAL_SIZE); copy_properties (source, t); t->parent = parent; if (! NULL_LEFT_CHILD (source)) t->left = reproduce_tree (source->left, t); if (! NULL_RIGHT_CHILD (source)) t->right = reproduce_tree (source->right, t); return t; } #if 0 /* Nobody calls this. Perhaps it's a vestige of an earlier design. */ /* Make a new interval of length LENGTH starting at START in the group of intervals INTERVALS, which is actually an interval tree. Returns the new interval. Generate an error if the new positions would overlap an existing interval. */ static INTERVAL make_new_interval (intervals, start, length) INTERVAL intervals; int start, length; { INTERVAL slot; slot = find_interval (intervals, start); if (start + length > slot->position + LENGTH (slot)) error ("Interval would overlap"); if (start == slot->position && length == LENGTH (slot)) return slot; if (slot->position == start) { /* New right node. */ split_interval_right (slot, length); return slot; } if (slot->position + LENGTH (slot) == start + length) { /* New left node. */ split_interval_left (slot, LENGTH (slot) - length); return slot; } /* Convert interval SLOT into three intervals. */ split_interval_left (slot, start - slot->position); split_interval_right (slot, length); return slot; } #endif /* Insert the intervals of SOURCE into BUFFER at POSITION. LENGTH is the length of the text in SOURCE. This is used in insdel.c when inserting Lisp_Strings into the buffer. The text corresponding to SOURCE is already in the buffer when this is called. The intervals of new tree are a copy of those belonging to the string being inserted; intervals are never shared. If the inserted text had no intervals associated, and we don't want to inherit the surrounding text's properties, this function simply returns -- offset_intervals should handle placing the text in the correct interval, depending on the sticky bits. If the inserted text had properties (intervals), then there are two cases -- either insertion happened in the middle of some interval, or between two intervals. If the text goes into the middle of an interval, then new intervals are created in the middle with only the properties of the new text, *unless* the macro MERGE_INSERTIONS is true, in which case the new text has the union of its properties and those of the text into which it was inserted. If the text goes between two intervals, then if neither interval had its appropriate sticky property set (front_sticky, rear_sticky), the new text has only its properties. If one of the sticky properties is set, then the new text "sticks" to that region and its properties depend on merging as above. If both the preceding and succeeding intervals to the new text are "sticky", then the new text retains only its properties, as if neither sticky property were set. Perhaps we should consider merging all three sets of properties onto the new text... */ void graft_intervals_into_buffer (source, position, length, buffer, inherit) INTERVAL source; int position, length; struct buffer *buffer; int inherit; { register INTERVAL under, over, this, prev; register INTERVAL tree; int middle; tree = BUF_INTERVALS (buffer); /* If the new text has no properties, it becomes part of whatever interval it was inserted into. */ if (NULL_INTERVAL_P (source)) { Lisp_Object buf; if (!inherit && ! NULL_INTERVAL_P (tree)) { XSETBUFFER (buf, buffer); Fset_text_properties (make_number (position), make_number (position + length), Qnil, buf); } if (! NULL_INTERVAL_P (BUF_INTERVALS (buffer))) BUF_INTERVALS (buffer) = balance_an_interval (BUF_INTERVALS (buffer)); return; } if (NULL_INTERVAL_P (tree)) { /* The inserted text constitutes the whole buffer, so simply copy over the interval structure. */ if ((BUF_Z (buffer) - BUF_BEG (buffer)) == TOTAL_LENGTH (source)) { Lisp_Object buf; XSETBUFFER (buf, buffer); BUF_INTERVALS (buffer) = reproduce_tree (source, buf); /* Explicitly free the old tree here. */ return; } /* Create an interval tree in which to place a copy of the intervals of the inserted string. */ { Lisp_Object buf; XSETBUFFER (buf, buffer); tree = create_root_interval (buf); } } else if (TOTAL_LENGTH (tree) == TOTAL_LENGTH (source)) /* If the buffer contains only the new string, but there was already some interval tree there, then it may be some zero length intervals. Eventually, do something clever about inserting properly. For now, just waste the old intervals. */ { BUF_INTERVALS (buffer) = reproduce_tree (source, tree->parent); /* Explicitly free the old tree here. */ return; } /* Paranoia -- the text has already been added, so this buffer should be of non-zero length. */ else if (TOTAL_LENGTH (tree) == 0) abort (); this = under = find_interval (tree, position); if (NULL_INTERVAL_P (under)) /* Paranoia */ abort (); over = find_interval (source, 1); /* Here for insertion in the middle of an interval. Split off an equivalent interval to the right, then don't bother with it any more. */ if (position > under->position) { INTERVAL end_unchanged = split_interval_left (this, position - under->position); copy_properties (under, end_unchanged); under->position = position; prev = 0; middle = 1; } else { prev = previous_interval (under); if (prev && !END_NONSTICKY_P (prev)) prev = 0; } /* Insertion is now at beginning of UNDER. */ /* The inserted text "sticks" to the interval `under', which means it gets those properties. The properties of under are the result of adjust_intervals_for_insertion, so stickiness has already been taken care of. */ while (! NULL_INTERVAL_P (over)) { if (LENGTH (over) < LENGTH (under)) { this = split_interval_left (under, LENGTH (over)); copy_properties (under, this); } else this = under; copy_properties (over, this); if (inherit) merge_properties (over, this); else copy_properties (over, this); over = next_interval (over); } if (! NULL_INTERVAL_P (BUF_INTERVALS (buffer))) BUF_INTERVALS (buffer) = balance_an_interval (BUF_INTERVALS (buffer)); return; } /* Get the value of property PROP from PLIST, which is the plist of an interval. We check for direct properties, for categories with property PROP, and for PROP appearing on the default-text-properties list. */ Lisp_Object textget (plist, prop) Lisp_Object plist; register Lisp_Object prop; { register Lisp_Object tail, fallback; fallback = Qnil; for (tail = plist; !NILP (tail); tail = Fcdr (Fcdr (tail))) { register Lisp_Object tem; tem = Fcar (tail); if (EQ (prop, tem)) return Fcar (Fcdr (tail)); if (EQ (tem, Qcategory)) { tem = Fcar (Fcdr (tail)); if (SYMBOLP (tem)) fallback = Fget (tem, prop); } } if (! NILP (fallback)) return fallback; if (CONSP (Vdefault_text_properties)) return Fplist_get (Vdefault_text_properties, prop); return Qnil; } /* Set point in BUFFER to POSITION. If the target position is before an intangible character, move to an ok place. */ void set_point (position, buffer) register int position; register struct buffer *buffer; { register INTERVAL to, from, toprev, fromprev, target; int buffer_point; register Lisp_Object obj; int backwards = (position < BUF_PT (buffer)) ? 1 : 0; int old_position = BUF_PT (buffer); buffer->point_before_scroll = Qnil; if (position == BUF_PT (buffer)) return; /* Check this now, before checking if the buffer has any intervals. That way, we can catch conditions which break this sanity check whether or not there are intervals in the buffer. */ if (position > BUF_Z (buffer) || position < BUF_BEG (buffer)) abort (); if (NULL_INTERVAL_P (BUF_INTERVALS (buffer))) { BUF_PT (buffer) = position; return; } /* Set TO to the interval containing the char after POSITION, and TOPREV to the interval containing the char before POSITION. Either one may be null. They may be equal. */ to = find_interval (BUF_INTERVALS (buffer), position); if (position == BUF_BEGV (buffer)) toprev = 0; else if (to->position == position) toprev = previous_interval (to); else toprev = to; buffer_point = (BUF_PT (buffer) == BUF_ZV (buffer) ? BUF_ZV (buffer) - 1 : BUF_PT (buffer)); /* Set FROM to the interval containing the char after PT, and FROMPREV to the interval containing the char before PT. Either one may be null. They may be equal. */ /* We could cache this and save time. */ from = find_interval (BUF_INTERVALS (buffer), buffer_point); if (buffer_point == BUF_BEGV (buffer)) fromprev = 0; else if (from->position == BUF_PT (buffer)) fromprev = previous_interval (from); else if (buffer_point != BUF_PT (buffer)) fromprev = from, from = 0; else fromprev = from; /* Moving within an interval. */ if (to == from && toprev == fromprev && INTERVAL_VISIBLE_P (to)) { BUF_PT (buffer) = position; return; } /* If the new position is between two intangible characters with the same intangible property value, move forward or backward until a change in that property. */ if (NILP (Vinhibit_point_motion_hooks) && ! NULL_INTERVAL_P (to) && ! NULL_INTERVAL_P (toprev)) { if (backwards) { Lisp_Object intangible_propval; intangible_propval = textget (to->plist, Qintangible); /* If following char is intangible, skip back over all chars with matching intangible property. */ if (! NILP (intangible_propval)) while (to == toprev || ((! NULL_INTERVAL_P (toprev) && EQ (textget (toprev->plist, Qintangible), intangible_propval)))) { to = toprev; toprev = previous_interval (toprev); if (NULL_INTERVAL_P (toprev)) position = BUF_BEGV (buffer); else /* This is the only line that's not dual to the following loop. That's because we want the position at the end of TOPREV. */ position = to->position; } } else { Lisp_Object intangible_propval; intangible_propval = textget (toprev->plist, Qintangible); /* If previous char is intangible, skip fwd over all chars with matching intangible property. */ if (! NILP (intangible_propval)) while (to == toprev || ((! NULL_INTERVAL_P (to) && EQ (textget (to->plist, Qintangible), intangible_propval)))) { toprev = to; to = next_interval (to); if (NULL_INTERVAL_P (to)) position = BUF_ZV (buffer); else position = to->position; } } } /* Here TO is the interval after the stopping point and TOPREV is the interval before the stopping point. One or the other may be null. */ BUF_PT (buffer) = position; /* We run point-left and point-entered hooks here, iff the two intervals are not equivalent. These hooks take (old_point, new_point) as arguments. */ if (NILP (Vinhibit_point_motion_hooks) && (! intervals_equal (from, to) || ! intervals_equal (fromprev, toprev))) { Lisp_Object leave_after, leave_before, enter_after, enter_before; if (fromprev) leave_after = textget (fromprev->plist, Qpoint_left); else leave_after = Qnil; if (from) leave_before = textget (from->plist, Qpoint_left); else leave_before = Qnil; if (toprev) enter_after = textget (toprev->plist, Qpoint_entered); else enter_after = Qnil; if (to) enter_before = textget (to->plist, Qpoint_entered); else enter_before = Qnil; if (! EQ (leave_before, enter_before) && !NILP (leave_before)) call2 (leave_before, old_position, position); if (! EQ (leave_after, enter_after) && !NILP (leave_after)) call2 (leave_after, old_position, position); if (! EQ (enter_before, leave_before) && !NILP (enter_before)) call2 (enter_before, old_position, position); if (! EQ (enter_after, leave_after) && !NILP (enter_after)) call2 (enter_after, old_position, position); } } /* Set point temporarily, without checking any text properties. */ INLINE void temp_set_point (position, buffer) int position; struct buffer *buffer; { BUF_PT (buffer) = position; } /* Return the proper local map for position POSITION in BUFFER. Use the map specified by the local-map property, if any. Otherwise, use BUFFER's local map. */ Lisp_Object get_local_map (position, buffer) register int position; register struct buffer *buffer; { Lisp_Object prop, tem, lispy_position, lispy_buffer; int old_begv, old_zv; /* Perhaps we should just change `position' to the limit. */ if (position > BUF_Z (buffer) || position < BUF_BEG (buffer)) abort (); /* Ignore narrowing, so that a local map continues to be valid even if the visible region contains no characters and hence no properties. */ old_begv = BUF_BEGV (buffer); old_zv = BUF_ZV (buffer); BUF_BEGV (buffer) = BUF_BEG (buffer); BUF_ZV (buffer) = BUF_Z (buffer); /* There are no properties at the end of the buffer, so in that case check for a local map on the last character of the buffer instead. */ if (position == BUF_Z (buffer) && BUF_Z (buffer) > BUF_BEG (buffer)) --position; XSETFASTINT (lispy_position, position); XSETBUFFER (lispy_buffer, buffer); prop = Fget_char_property (lispy_position, Qlocal_map, lispy_buffer); BUF_BEGV (buffer) = old_begv; BUF_ZV (buffer) = old_zv; /* Use the local map only if it is valid. */ if (!NILP (prop) && (tem = Fkeymapp (prop), !NILP (tem))) return prop; return buffer->keymap; } /* Produce an interval tree reflecting the intervals in TREE from START to START + LENGTH. */ INTERVAL copy_intervals (tree, start, length) INTERVAL tree; int start, length; { register INTERVAL i, new, t; register int got, prevlen; if (NULL_INTERVAL_P (tree) || length <= 0) return NULL_INTERVAL; i = find_interval (tree, start); if (NULL_INTERVAL_P (i) || LENGTH (i) == 0) abort (); /* If there is only one interval and it's the default, return nil. */ if ((start - i->position + 1 + length) < LENGTH (i) && DEFAULT_INTERVAL_P (i)) return NULL_INTERVAL; new = make_interval (); new->position = 1; got = (LENGTH (i) - (start - i->position)); new->total_length = length; copy_properties (i, new); t = new; prevlen = got; while (got < length) { i = next_interval (i); t = split_interval_right (t, prevlen); copy_properties (i, t); prevlen = LENGTH (i); got += prevlen; } return balance_an_interval (new); } /* Give STRING the properties of BUFFER from POSITION to LENGTH. */ INLINE void copy_intervals_to_string (string, buffer, position, length) Lisp_Object string, buffer; int position, length; { INTERVAL interval_copy = copy_intervals (BUF_INTERVALS (XBUFFER (buffer)), position, length); if (NULL_INTERVAL_P (interval_copy)) return; interval_copy->parent = (INTERVAL) string; XSTRING (string)->intervals = interval_copy; } /* Return 1 if string S1 and S2 have identical properties; 0 otherwise. Assume they have identical characters. */ int compare_string_intervals (s1, s2) Lisp_Object s1, s2; { INTERVAL i1, i2; int pos = 1; int end = XSTRING (s1)->size + 1; /* We specify 1 as position because the interval functions always use positions starting at 1. */ i1 = find_interval (XSTRING (s1)->intervals, 1); i2 = find_interval (XSTRING (s2)->intervals, 1); while (pos < end) { /* Determine how far we can go before we reach the end of I1 or I2. */ int len1 = (i1 != 0 ? INTERVAL_LAST_POS (i1) : end) - pos; int len2 = (i2 != 0 ? INTERVAL_LAST_POS (i2) : end) - pos; int distance = min (len1, len2); /* If we ever find a mismatch between the strings, they differ. */ if (! intervals_equal (i1, i2)) return 0; /* Advance POS till the end of the shorter interval, and advance one or both interval pointers for the new position. */ pos += distance; if (len1 == distance) i1 = next_interval (i1); if (len2 == distance) i2 = next_interval (i2); } return 1; } #endif /* USE_TEXT_PROPERTIES */