src/intervals.h

   1 /* Definitions and global variables for intervals.
   2    Copyright (C) 1993-1994, 2000-2018 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs is free software: you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation, either version 3 of the License, or (at
   9 your option) any later version.
  10
  11 GNU Emacs is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef EMACS_INTERVALS_H
  20 #define EMACS_INTERVALS_H
  21
  22 #include "buffer.h"
  23 #include "lisp.h"
  24
  25 INLINE_HEADER_BEGIN
  26
  27 /* Basic data type for use of intervals.  */
  28
  29 struct interval
  30 {
  31   /* The first group of entries deal with the tree structure.  */
  32
  33   ptrdiff_t total_length;       /* Length of myself and both children.  */
  34   ptrdiff_t position;           /* Cache of interval's character position.  */
  35                                 /* This field is usually updated
  36                                    simultaneously with an interval
  37                                    traversal, there is no guarantee
  38                                    that it is valid for a random
  39                                    interval.  */
  40   struct interval *left;        /* Intervals which precede me.  */
  41   struct interval *right;       /* Intervals which succeed me.  */
  42
  43   /* Parent in the tree, or the Lisp_Object containing this interval tree.  */
  44   union
  45   {
  46     struct interval *interval;
  47     Lisp_Object obj;
  48   } up;
  49   bool_bf up_obj : 1;
  50
  51   bool_bf gcmarkbit : 1;
  52
  53   /* The remaining components are `properties' of the interval.
  54      The first four are duplicates for things which can be on the list,
  55      for purposes of speed.  */
  56
  57   bool_bf write_protect : 1;        /* True means can't modify.  */
  58   bool_bf visible : 1;              /* False means don't display.  */
  59   bool_bf front_sticky : 1;         /* True means text inserted just
  60                                        before this interval goes into it.  */
  61   bool_bf rear_sticky : 1;          /* Likewise for just after it.  */
  62   Lisp_Object plist;                /* Other properties.  */
  63 };
  64
  65 /* These are macros for dealing with the interval tree.  */
  66
  67 /* True if this interval has no right child.  */
  68 #define NULL_RIGHT_CHILD(i) ((i)->right == NULL)
  69
  70 /* True if this interval has no left child.  */
  71 #define NULL_LEFT_CHILD(i) ((i)->left == NULL)
  72
  73 /* True if this interval has no parent.  */
  74 #define NULL_PARENT(i) ((i)->up_obj || (i)->up.interval == 0)
  75
  76 /* True if this interval is the left child of some other interval.  */
  77 #define AM_LEFT_CHILD(i)                                        \
  78   (! NULL_PARENT (i) && INTERVAL_PARENT (i)->left == (i))
  79
  80 /* True if this interval is the right child of some other interval.  */
  81 #define AM_RIGHT_CHILD(i)                                       \
  82   (! NULL_PARENT (i) && INTERVAL_PARENT (i)->right == (i))
  83
  84 /* True if this interval has no children.  */
  85 #define LEAF_INTERVAL_P(i) ((i)->left == NULL && (i)->right == NULL)
  86
  87 /* True if this interval has no parent and is therefore the root.  */
  88 #define ROOT_INTERVAL_P(i) NULL_PARENT (i)
  89
  90 /* True if this interval is the only interval in the interval tree.  */
  91 #define ONLY_INTERVAL_P(i) (ROOT_INTERVAL_P (i) && LEAF_INTERVAL_P (i))
  92
  93 /* True if this interval has both left and right children.  */
  94 #define BOTH_KIDS_P(i) ((i)->left != NULL && (i)->right != NULL)
  95
  96 /* The total size of all text represented by this interval and all its
  97    children in the tree.   This is zero if the interval is null.  */
  98 #define TOTAL_LENGTH(i) ((i) == NULL ? 0 : (i)->total_length)
  99
 100 /* The size of text represented by this interval alone.  */
 101 #define LENGTH(i) ((i)->total_length                    \
 102                    - TOTAL_LENGTH ((i)->right)          \
 103                    - TOTAL_LENGTH ((i)->left))
 104
 105 /* The position of the character just past the end of I.  Note that
 106    the position cache i->position must be valid for this to work.  */
 107 #define INTERVAL_LAST_POS(i) ((i)->position + LENGTH (i))
 108
 109 /* The total size of the left subtree of this interval.  */
 110 #define LEFT_TOTAL_LENGTH(i) ((i)->left ? (i)->left->total_length : 0)
 111
 112 /* The total size of the right subtree of this interval.  */
 113 #define RIGHT_TOTAL_LENGTH(i) ((i)->right ? (i)->right->total_length : 0)
 114
 115 /* These macros are for dealing with the interval properties.  */
 116
 117 /* True if this is a default interval, which is the same as being null
 118    or having no properties.  */
 119 #define DEFAULT_INTERVAL_P(i) (!i || EQ ((i)->plist, Qnil))
 120
 121 /* Test what type of parent we have.  Three possibilities: another
 122    interval, a buffer or string object, or NULL.  */
 123 #define INTERVAL_HAS_PARENT(i) (! (i)->up_obj && (i)->up.interval != 0)
 124 #define INTERVAL_HAS_OBJECT(i) ((i)->up_obj)
 125
 126 /* Use these macros to get parent of an interval.
 127
 128    The choice of macros is dependent on the type needed.  Don't add
 129    casts to get around this, it will break some development work in
 130    progress.  */
 131
 132 #define INTERVAL_PARENT(i)                                      \
 133    (eassert ((i) != 0 && ! (i)->up_obj), (i)->up.interval)
 134
 135 #define GET_INTERVAL_OBJECT(d,s) (eassert ((s)->up_obj), (d) = (s)->up.obj)
 136
 137 /* Use these functions to set Lisp_Object
 138    or pointer slots of struct interval.  */
 139
 140 INLINE void
 141 set_interval_object (INTERVAL i, Lisp_Object obj)
 142 {
 143   eassert (BUFFERP (obj) || STRINGP (obj));
 144   i->up_obj = 1;
 145   i->up.obj = obj;
 146 }
 147
 148 INLINE void
 149 set_interval_parent (INTERVAL i, INTERVAL parent)
 150 {
 151   i->up_obj = false;
 152   i->up.interval = parent;
 153 }
 154
 155 INLINE void
 156 set_interval_plist (INTERVAL i, Lisp_Object plist)
 157 {
 158   i->plist = plist;
 159 }
 160
 161 /* Get the parent interval, if any, otherwise a null pointer.  Useful
 162    for walking up to the root in a "for" loop; use this to get the
 163    "next" value, and test the result to see if it's NULL.  */
 164 #define INTERVAL_PARENT_OR_NULL(i) \
 165    (INTERVAL_HAS_PARENT (i) ? INTERVAL_PARENT (i) : 0)
 166
 167 /* Reset this interval to its vanilla, or no-property state.  */
 168 #define RESET_INTERVAL(i)                     \
 169  do {                                         \
 170   (i)->total_length = (i)->position = 0;      \
 171   (i)->left = (i)->right = NULL;              \
 172   set_interval_parent (i, NULL);              \
 173   (i)->write_protect = false;                 \
 174   (i)->visible = false;                       \
 175   (i)->front_sticky = (i)->rear_sticky = false; \
 176   set_interval_plist (i, Qnil);               \
 177  } while (false)
 178
 179 /* Copy the cached property values of interval FROM to interval TO.  */
 180 #define COPY_INTERVAL_CACHE(from,to)            \
 181  do {                                           \
 182   (to)->write_protect = (from)->write_protect;  \
 183   (to)->visible = (from)->visible;              \
 184   (to)->front_sticky = (from)->front_sticky;    \
 185   (to)->rear_sticky = (from)->rear_sticky;      \
 186  } while (false)
 187
 188 /* Copy only the set bits of FROM's cache.  */
 189 #define MERGE_INTERVAL_CACHE(from,to)                           \
 190  do {                                                           \
 191   if ((from)->write_protect) (to)->write_protect = true;        \
 192   if ((from)->visible) (to)->visible = true;                    \
 193   if ((from)->front_sticky) (to)->front_sticky = true;          \
 194   if ((from)->rear_sticky) (to)->rear_sticky = true;            \
 195  } while (false)
 196
 197 /* Is this interval visible?  Replace later with cache access.  */
 198 #define INTERVAL_VISIBLE_P(i) \
 199   (i && NILP (textget ((i)->plist, Qinvisible)))
 200
 201 /* Is this interval writable?  Replace later with cache access.  */
 202 #define INTERVAL_WRITABLE_P(i)                                  \
 203   (NILP (textget ((i)->plist, Qread_only))                      \
 204    || !NILP (textget ((i)->plist, Qinhibit_read_only))          \
 205    || ((CONSP (Vinhibit_read_only)                              \
 206         ? !NILP (Fmemq (textget ((i)->plist, Qread_only),       \
 207                         Vinhibit_read_only))                    \
 208         : !NILP (Vinhibit_read_only))))
 209
 210 /* Macros to tell whether insertions before or after this interval
 211    should stick to it.  Now we have Vtext_property_default_nonsticky,
 212    so these macros are unreliable now and never used.  */
 213
 214 #if false
 215 #define FRONT_STICKY_P(i)                               \
 216   (i && ! NILP (textget ((i)->plist, Qfront_sticky)))
 217 #define END_NONSTICKY_P(i)                              \
 218   (i && ! NILP (textget ((i)->plist, Qrear_nonsticky)))
 219 #define FRONT_NONSTICKY_P(i)                            \
 220   (i && ! EQ (Qt, textget ((i)->plist, Qfront_sticky)))
 221 #endif
 222
 223 /* If PROP is the `invisible' property of a character,
 224    this is 1 if the character should be treated as invisible,
 225    and 2 if it is invisible but with an ellipsis.  */
 226
 227 #define TEXT_PROP_MEANS_INVISIBLE(prop)                                 \
 228   (EQ (BVAR (current_buffer, invisibility_spec), Qt)                    \
 229    ? !NILP (prop)                                                       \
 230    : invisible_prop (prop, BVAR (current_buffer, invisibility_spec)))
 231
 232 /* Declared in alloc.c.  */
 233
 234 extern INTERVAL make_interval (void);
 235
 236 /* Declared in intervals.c.  */
 237
 238 extern INTERVAL create_root_interval (Lisp_Object);
 239 extern void copy_properties (INTERVAL, INTERVAL);
 240 extern bool intervals_equal (INTERVAL, INTERVAL);
 241 extern void traverse_intervals (INTERVAL, ptrdiff_t,
 242                                 void (*) (INTERVAL, Lisp_Object),
 243                                 Lisp_Object);
 244 extern void traverse_intervals_noorder (INTERVAL,
 245                                         void (*) (INTERVAL, void *), void *);
 246 extern INTERVAL split_interval_right (INTERVAL, ptrdiff_t);
 247 extern INTERVAL split_interval_left (INTERVAL, ptrdiff_t);
 248 extern INTERVAL find_interval (INTERVAL, ptrdiff_t);
 249 extern INTERVAL next_interval (INTERVAL);
 250 extern INTERVAL previous_interval (INTERVAL);
 251 extern INTERVAL merge_interval_left (INTERVAL);
 252 extern void offset_intervals (struct buffer *, ptrdiff_t, ptrdiff_t);
 253 extern void graft_intervals_into_buffer (INTERVAL, ptrdiff_t, ptrdiff_t,
 254                                          struct buffer *, bool);
 255 extern void verify_interval_modification (struct buffer *,
 256                                           ptrdiff_t, ptrdiff_t);
 257 extern INTERVAL balance_intervals (INTERVAL);
 258 extern void copy_intervals_to_string (Lisp_Object, struct buffer *,
 259                                              ptrdiff_t, ptrdiff_t);
 260 extern INTERVAL copy_intervals (INTERVAL, ptrdiff_t, ptrdiff_t);
 261 extern bool compare_string_intervals (Lisp_Object, Lisp_Object);
 262 extern Lisp_Object textget (Lisp_Object, Lisp_Object);
 263 extern Lisp_Object lookup_char_property (Lisp_Object, Lisp_Object, bool);
 264 extern void move_if_not_intangible (ptrdiff_t);
 265 extern bool get_property_and_range (ptrdiff_t, Lisp_Object, Lisp_Object *,
 266                                     ptrdiff_t *, ptrdiff_t *, Lisp_Object);
 267 extern Lisp_Object get_local_map (ptrdiff_t, struct buffer *, Lisp_Object);
 268 extern INTERVAL update_interval (INTERVAL, ptrdiff_t);
 269 extern void set_intervals_multibyte (bool);
 270 extern INTERVAL validate_interval_range (Lisp_Object, Lisp_Object *,
 271                                          Lisp_Object *, bool);
 272 extern INTERVAL interval_of (ptrdiff_t, Lisp_Object);
 273
 274 /* Defined in xdisp.c.  */
 275 extern int invisible_prop (Lisp_Object, Lisp_Object);
 276
 277 /* Defined in textprop.c.  */
 278 extern Lisp_Object copy_text_properties (Lisp_Object, Lisp_Object,
 279                                          Lisp_Object, Lisp_Object,
 280                                          Lisp_Object, Lisp_Object);
 281 extern Lisp_Object set_text_properties (Lisp_Object, Lisp_Object,
 282                                         Lisp_Object, Lisp_Object,
 283                                         Lisp_Object);
 284 extern void set_text_properties_1 (Lisp_Object, Lisp_Object,
 285                                    Lisp_Object, Lisp_Object, INTERVAL);
 286
 287 Lisp_Object text_property_list (Lisp_Object, Lisp_Object, Lisp_Object,
 288                                 Lisp_Object);
 289 void add_text_properties_from_list (Lisp_Object, Lisp_Object, Lisp_Object);
 290 Lisp_Object extend_property_ranges (Lisp_Object, Lisp_Object, Lisp_Object);
 291 Lisp_Object get_char_property_and_overlay (Lisp_Object, Lisp_Object,
 292                                            Lisp_Object, Lisp_Object *);
 293 extern int text_property_stickiness (Lisp_Object prop, Lisp_Object pos,
 294                                      Lisp_Object buffer);
 295
 296 extern void syms_of_textprop (void);
 297
 298 INLINE_HEADER_END
 299
 300 #endif /* EMACS_INTERVALS_H */