entered into RCS

2 files changed, 319 insertions, 42 deletions

diff --git a/src/intervals.c b/src/intervals.c
index 8a985199f8e..0a653748da9 100644
--- a/src/intervals.c
+++ b/src/intervals.c
@@ -345,24 +345,28 @@ rotate_left (interval)
   return B;
 }
 
-/* Split an interval into two.  The second (RIGHT) half is returned as
-   the new interval.  The size and position of the interval being split are
-   stored within it, having been found by find_interval ().  The properties
-   are reset;  it is up to the caller to do the right thing.
+/* Split INTERVAL into two pieces, starting the second piece at character
+   position OFFSET (counting from 1), relative to INTERVAL.  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, relative_position)
+split_interval_right (interval, offset)
      INTERVAL interval;
-     int relative_position;
+     int offset;
 {
   INTERVAL new = make_interval ();
   int position = interval->position;
-  int new_length = LENGTH (interval) - relative_position + 1;
+  int new_length = LENGTH (interval) - offset + 1;
 
-  new->position = position + relative_position - 1;
+  new->position = position + offset - 1;
   new->parent = interval;
 #if 0
   copy_properties (interval, new);
@@ -386,22 +390,26 @@ split_interval_right (interval, relative_position)
   return new;
 }
 
-/* Split an interval into two.  The first (LEFT) half is returned as
-   the new interval.  The size and position of the interval being split
-   are stored within it, having been found by find_interval ().  The
-   properties are reset;  it is up to the caller to do the right thing.
+/* Split INTERVAL into two pieces, starting the second piece at character
+   position OFFSET (counting from 1), relative to INTERVAL.  The left-hand
+   piece (first, lexicographically) is returned.
 
-   Note that this does not change the position of INTERVAL in the tree;  if it
-   is a root, it is still a root after this operation.  */
+   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, relative_position)
+split_interval_left (interval, offset)
      INTERVAL interval;
-     int relative_position;
+     int offset;
 {
   INTERVAL new = make_interval ();
   int position = interval->position;
-  int new_length = relative_position - 1;
+  int new_length = offset - 1;
 
 #if 0
   copy_properties (interval, new);
@@ -409,7 +417,7 @@ split_interval_left (interval, relative_position)
 
   new->position = interval->position;
 
-  interval->position = interval->position + relative_position - 1;
+  interval->position = interval->position + offset - 1;
   new->parent = interval;
 
   if (NULL_LEFT_CHILD (interval))
@@ -429,10 +437,15 @@ split_interval_left (interval, relative_position)
   return new;
 }
 
-/* Find the interval containing POSITION in TREE.  POSITION is relative
-   to the start of TREE. */
+/* Find the interval containing text position POSITION in the text
+   represented by the interval tree TREE.  POSITION is relative to
+   the beginning of that text.
 
-INTERVAL
+   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;
@@ -471,10 +484,8 @@ find_interval (tree, position)
 }
 
 /* Find the succeeding interval (lexicographically) to INTERVAL.
-   Sets the `position' field based on that of INTERVAL.
-
-   Note that those values are only correct if they were also correct
-   in INTERVAL. */
+   Sets the `position' field based on that of INTERVAL (see
+   find_interval). */
 
 INTERVAL
 next_interval (interval)
@@ -513,10 +524,8 @@ next_interval (interval)
 }
 
 /* Find the preceding interval (lexicographically) to INTERVAL.
-   Sets the `position' field based on that of INTERVAL.
-
-   Note that those values are only correct if they were also correct
-   in INTERVAL. */
+   Sets the `position' field based on that of INTERVAL (see
+   find_interval). */
 
 INTERVAL
 previous_interval (interval)
@@ -554,6 +563,7 @@ previous_interval (interval)
   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
@@ -610,6 +620,59 @@ adjust_intervals_for_insertion (tree, position, length)
         }
     }
 }
+#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 it's 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 "stick", 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;
+
+  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);
+
+  i = find_interval (tree, position);
+  /* If we are positioned between intervals, check the stickiness of
+     both of them. */
+  if (position == i->position
+      && position != 1)
+    {
+      register prev = previous_interval (i);
+
+      /* If both intervals are sticky here, then default to the
+         left-most one.  But perhaps we should create a new
+         interval here instead... */
+      if (END_STICKY (prev))
+        i = prev;
+    }
+
+  while (! NULL_INTERVAL_P (i))
+    {
+      i->total_length += length;
+      i = i->parent
+    }
+
+  return tree;
+}
 
 /* Merge interval I with its lexicographic successor. Note that
    this does not deal with the properties, or delete I. */
@@ -697,8 +760,8 @@ merge_interval_left (i)
   return NULL_INTERVAL;
 }
 
-/* Delete an interval node from its btree by merging its subtrees
-   into one subtree which is returned.  Caller is responsible for
+/* 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
@@ -1002,7 +1065,7 @@ map_intervals (source, destination, position)
 
    If the inserted text had no intervals associated, this function
    simply returns -- offset_intervals should handle placing the
-   text in the correct interval, depending on the hungry bits.
+   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,
@@ -1015,12 +1078,12 @@ map_intervals (source, destination, position)
    of the text into which it was inserted.
 
    If the text goes between two intervals, then if neither interval
-   had its appropriate hungry property set (front_hungry, rear_hungry),
-   the new text has only its properties.  If one of the hungry properties
+   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 succeding
-   intervals to the new text are "hungry", then the new text retains
-   only its properties, as if neither hungry property were set.  Perhaps
+   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... */
 
@@ -1088,7 +1151,7 @@ graft_intervals_into_buffer (new_tree, position, b)
       /* First interval -- none precede it. */
       if (position == 1)
         {
-          if (! under->front_hungry)
+          if (! FRONT_STICKY (under))
             /* The inserted string keeps its own properties. */
             while (! NULL_INTERVAL_P (over))
             {
@@ -1115,10 +1178,10 @@ graft_intervals_into_buffer (new_tree, position, b)
           if (NULL_INTERVAL_P (prev))
             abort ();
 
-          if (prev->rear_hungry)
+          if (END_STICKY (prev))
             {
-              if (under->front_hungry)
-                /* The intervals go inbetween as the two hungry
+              if (FRONT_STICKY (under))
+                /* The intervals go inbetween as the two sticky
                    properties cancel each other.  Should we change
                    this policy? */
                 while (! NULL_INTERVAL_P (over))
@@ -1142,7 +1205,7 @@ graft_intervals_into_buffer (new_tree, position, b)
             }
           else
             {
-              if (under->front_hungry)
+              if (FRONT_STICKY (under))
                 /* The intervals stick to under */
                 while (! NULL_INTERVAL_P (over))
                   {
@@ -1334,7 +1397,7 @@ verify_interval_modification (buf, start, end)
         abort ();
 
       i = find_interval (intervals, start - 1);
-      if (! END_HUNGRY_P (i))
+      if (! END_STICKY_P (i))
         return;
     }
   else
diff --git a/src/intervals.h b/src/intervals.h
new file mode 100644
index 00000000000..48d3daeaad1
--- /dev/null
+++ b/src/intervals.h
@@ -0,0 +1,214 @@
+/* Definitions and global variables for intervals.
+   Copyright (C) 1990, 1992 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#ifdef USE_INTERVALS
+#include "dispextern.h"
+
+#define NULL_INTERVAL 0
+#define INTERVAL_DEFAULT NULL_INTERVAL
+
+/* These are macros for dealing with the interval tree. */
+
+/* Size of the structure used to represent an interval */
+#define INTERVAL_SIZE (sizeof (struct interval))
+
+/* Size of a pointer to an interval structure */
+#define INTERVAL_PTR_SIZE (sizeof (struct interval *))
+
+/* True if an interval pointer is null, or is a Lisp_Buffer or
+   Lisp_String pointer (meaning it points to the owner of this
+   interval tree.) */
+#define NULL_INTERVAL_P(i) ((i) == NULL_INTERVAL ||                    \
+                            XTYPE ((Lisp_Object)(i)) == Lisp_Buffer || \
+                            XTYPE ((Lisp_Object)(i)) == Lisp_String)
+
+/* True if this interval has no right child. */
+#define NULL_RIGHT_CHILD(i) (NULL_INTERVAL_P((i)->right))
+
+/* True if this interval has no left child. */
+#define NULL_LEFT_CHILD(i) (NULL_INTERVAL_P((i)->left))
+
+/* True if this interval has no parent. */
+#define NULL_PARENT(i) (NULL_INTERVAL_P((i)->parent))
+
+/* True if this interval is the left child of some other interval. */
+#define AM_LEFT_CHILD(i) (! NULL_INTERVAL_P ((i)->parent) \
+                          && (i)->parent->left == (i))
+
+/* True if this interval is the right ehild of some other interval. */
+#define AM_RIGHT_CHILD(i) (! NULL_INTERVAL_P ((i)->parent) \
+                           && (i)->parent->right == (i))
+
+/* True if this interval has no children. */
+#define LEAF_INTERVAL_P(i) ((i)->left == NULL_INTERVAL \
+                            && (i)->right == NULL_INTERVAL)
+
+/* True if this interval has no parent and is therefore the root. */
+#define ROOT_INTERVAL_P(i) (NULL_PARENT (i))
+
+/* True if this interval is the only interval in the interval tree. */
+#define ONLY_INTERVAL_P(i) (ROOT_INTERVAL_P((i)) && LEAF_INTERVAL_P ((i)))
+
+/* True if this interval has both left and right children. */
+#define BOTH_KIDS_P(i) ((i)->left != NULL_INTERVAL     \
+                        && (i)->right != NULL_INTERVAL)
+
+/* The total size of all text represented by this interval and all its
+   children in the tree.   This is zero if the interval is null. */
+#define TOTAL_LENGTH(i) ((i) == NULL_INTERVAL ? 0 : (i)->total_length)
+
+/* The size of text represented by this interval alone. */
+#define LENGTH(i) ((i) == NULL_INTERVAL ? 0 : (TOTAL_LENGTH ((i))          \
+                                               - TOTAL_LENGTH ((i)->right) \
+                                               - TOTAL_LENGTH ((i)->left)))
+
+/* The absolute index of the last character belonging to I.  Note that
+   the position cache i->position must be valid for this to work. */
+#define INTERVAL_LAST_POS(i) ((i)->position + LENGTH ((i)) - 1)
+
+/* The total size of the left subtree of this interval. */
+#define LEFT_TOTAL_LENGTH(i) ((i)->left ? (i)->left->total_length : 0)
+
+/* The total size of the right subtree of this interval. */
+#define RIGHT_TOTAL_LENGTH(i) ((i)->right ? (i)->right->total_length : 0)
+
+
+/* These macros are for dealing with the interval properties. */
+
+/* True if this is a default interval, which is the same as being null
+   or having no properties. */
+#define DEFAULT_INTERVAL_P(i) (NULL_INTERVAL_P (i) || EQ ((i)->plist, Qnil))
+
+/* Reset this interval to its vanilla, or no-property state. */
+#define RESET_INTERVAL(i) { \
+                              (i)->total_length = (i)->position = 0;    \
+                              (i)->left = (i)->right = NULL_INTERVAL;   \
+                              (i)->parent = NULL_INTERVAL;              \
+                              (i)->write_protect = 0;                   \
+                              (i)->visible = 0;                         \
+                              (i)->front_sticky = (i)->rear_sticky = 0; \
+                              (i)->plist = Qnil;         \
+                          }
+
+/* Copy the cached property values of interval FROM to interval TO. */
+#define COPY_INTERVAL_CACHE(from,to) \
+{ \
+  (to)->write_protect = (from)->write_protect; \
+  (to)->visible = (from)->visible;             \
+  (to)->front_sticky = (from)->front_sticky;   \
+  (to)->rear_sticky = (from)->rear_sticky;     \
+}
+
+/* Copy only the set bits of FROM's cache. */
+#define MERGE_INTERVAL_CACHE(from,to) \
+{ \
+  if ((from)->write_protect) (to)->write_protect = 1; \
+  if ((from)->visible) (to)->visible = 1;             \
+  if ((from)->front_sticky) (to)->front_sticky = 1;   \
+  if ((from)->rear_sticky) (to)->rear_sticky = 1;     \
+}
+
+/* Macro determining whether the properties of an interval being
+   inserted should be merged with the properties of the text where
+   they are being inserted. */
+#define MERGE_INSERTIONS(i) 0
+
+/* Macro determining if an invisible interval should be displayed
+   as a special glyph, or not at all. */
+#define DISPLAY_INVISIBLE_GLYPH(i) 0
+
+/* Is this interval visible?  Replace later with cache access */
+#define INTERVAL_VISIBLE_P(i) \
+  (! NULL_INTERVAL_P (i) && ! NILP (Fmemq (Qinvisible, (i)->plist)))
+
+/* Is this interval writable?  Replace later with cache access */
+#define INTERVAL_WRITABLE_P(i) \
+  (! NULL_INTERVAL_P (i) && NILP (Fmemq (Qread_only, (i)->plist)))
+
+/* Macros to tell whether insertions before or after this interval
+   should stick to it. */
+#define FRONT_STICKY_P(i) ((i)->front_sticky != 0)
+#define END_STICKY_P(i) ((i)->rear_sticky != 0)
+
+
+/* Declared in alloc.c */
+
+extern INTERVAL make_interval ();
+
+/* Declared in intervals.c */
+
+extern INTERVAL mouse_interval;
+extern Lisp_Object Vmouse_buffer;
+extern int mouse_buffer_offset;
+extern Lisp_Object interval_balance_threshold;
+
+extern INTERVAL create_root_interval ();
+extern void copy_properties ();
+extern int intervals_equal ();
+extern void traverse_intervals ();
+extern INTERVAL split_interval_right (), split_interval_left ();
+extern INTERVAL find_interval (), next_interval (), previous_interval ();
+extern INTERVAL merge_interval_left (), merge_interval_right ();
+extern void delete_interval ();
+extern INLINE void offset_intervals ();
+extern void map_intervals ();
+extern void graft_intervals_into_buffer ();
+extern void set_point ();
+extern void verify_interval_modification ();
+extern INTERVAL balance_intervals ();
+extern void insert_interval_copy();
+extern void copy_intervals_to_string ();
+extern INTERVAL make_string_interval ();
+extern INTERVAL make_buffer_interval ();
+
+/* Declared in textprop.c */
+
+/* Types of hooks. */
+extern Lisp_Object Qmouse_left;
+extern Lisp_Object Qmouse_entered;
+extern Lisp_Object Qpoint_left;
+extern Lisp_Object Qpoint_entered;
+extern Lisp_Object Qmodification;
+
+/* Visual properties text (including strings) may have. */
+extern Lisp_Object Qforeground, Qbackground, Qfont, Qunderline, Qstipple;
+extern Lisp_Object Qinvisible, Qread_only;
+
+extern void run_hooks ();
+
+extern Lisp_Object Ftext_properties_at ();
+extern Lisp_Object Fnext_property_change (), Fprevious_property_change ();
+extern Lisp_Object Fadd_text_properties (), Fset_text_properties ();
+extern Lisp_Object Fremove_text_properties (), Ferase_text_properties ();
+
+extern void syms_of_textprop ();
+
+#else  /* intervals not used */
+
+#define NULL_INTERVAL_P(i) 1
+#define INTERVAL_SIZE 0
+#define INTERVAL_PTR_SIZE 0
+
+#define copy_intervals_to_string(string,buffer,position,length)
+#define verify_interval_modification(buffer,start,end)
+#define insert_interval_copy(source,position,end,sink,at)
+#define graft_intervals_into_buffer(tree,position,bufferptr)
+#define offset_intervals(buffer,position,length)
+
+#endif /* intervals not used */