code.delx.au - gnu-emacs/blob - src/syntax.h

   1 /* Declarations having to do with GNU Emacs syntax tables.
   2    Copyright (C) 1985, 1993, 1994, 1997 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 2, or (at your option)
   9 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; 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.  */
  20
  21
  22 extern Lisp_Object Qsyntax_table_p;
  23 extern void update_syntax_table P_ ((int, int, int, Lisp_Object));
  24
  25 /* The standard syntax table is stored where it will automatically
  26    be used in all new buffers.  */
  27 #define Vstandard_syntax_table buffer_defaults.syntax_table
  28
  29 /* A syntax table is a chartable whose elements are cons cells
  30    (CODE+FLAGS . MATCHING-CHAR).  MATCHING-CHAR can be nil if the char
  31    is not a kind of parenthesis.
  32
  33    The low 8 bits of CODE+FLAGS is a code, as follows:  */
  34
  35 enum syntaxcode
  36   {
  37     Swhitespace, /* for a whitespace character */
  38     Spunct,      /* for random punctuation characters */
  39     Sword,       /* for a word constituent */
  40     Ssymbol,     /* symbol constituent but not word constituent */
  41     Sopen,       /* for a beginning delimiter */
  42     Sclose,      /* for an ending delimiter */
  43     Squote,      /* for a prefix character like Lisp ' */
  44     Sstring,     /* for a string-grouping character like Lisp " */
  45     Smath,       /* for delimiters like $ in Tex.  */
  46     Sescape,     /* for a character that begins a C-style escape */
  47     Scharquote,  /* for a character that quotes the following character */
  48     Scomment,    /* for a comment-starting character */
  49     Sendcomment, /* for a comment-ending character */
  50     Sinherit,    /* use the standard syntax table for this character */
  51     Scomment_fence, /* Starts/ends comment which is delimited on the
  52                        other side by a char with the same syntaxcode.  */
  53     Sstring_fence,  /* Starts/ends string which is delimited on the
  54                        other side by a char with the same syntaxcode.  */
  55     Smax         /* Upper bound on codes that are meaningful */
  56   };
  57
  58 /* Set the syntax entry VAL for char C in table TABLE.  */
  59
  60 #define SET_RAW_SYNTAX_ENTRY(table, c, val)                             \
  61   ((c) < CHAR_TABLE_SINGLE_BYTE_SLOTS                                   \
  62    ? (XCHAR_TABLE (table)->contents[(unsigned char) (c)] = (val))       \
  63    : Faset ((table), make_number (c), (val)))
  64
  65 /* Fetch the syntax entry for char C in syntax table TABLE.
  66    This macro is called only when C is less than CHAR_TABLE_ORDINARY_SLOTS.
  67    Do inheritance.  */
  68
  69 #ifdef __GNUC__
  70 #define SYNTAX_ENTRY_FOLLOW_PARENT(table, c)                    \
  71   ({ Lisp_Object tbl = table;                                   \
  72      Lisp_Object temp = XCHAR_TABLE (tbl)->contents[(c)];       \
  73      while (NILP (temp))                                        \
  74        {                                                        \
  75          tbl = XCHAR_TABLE (tbl)->parent;                       \
  76          if (NILP (tbl))                                        \
  77            break;                                               \
  78          temp = XCHAR_TABLE (tbl)->contents[(c)];               \
  79        }                                                        \
  80      temp; })
  81 #else
  82 extern Lisp_Object syntax_temp;
  83 extern Lisp_Object syntax_parent_lookup P_ ((Lisp_Object, int));
  84
  85 #define SYNTAX_ENTRY_FOLLOW_PARENT(table, c)            \
  86   (syntax_temp = XCHAR_TABLE (table)->contents[(c)],    \
  87    (NILP (syntax_temp)                                  \
  88     ? syntax_parent_lookup (table, (c))                 \
  89     : syntax_temp))
  90 #endif
  91
  92 /* SYNTAX_ENTRY fetches the information from the entry for character C
  93    in syntax table TABLE, or from globally kept data (gl_state).
  94    Does inheritance.  */
  95 /* CURRENT_SYNTAX_TABLE gives the syntax table valid for current
  96    position, it is either the buffer's syntax table, or syntax table
  97    found in text properties.  */
  98
  99 #ifdef SYNTAX_ENTRY_VIA_PROPERTY
 100 #  define SYNTAX_ENTRY(c)                                             \
 101     (gl_state.use_global ? gl_state.global_code : SYNTAX_ENTRY_INT (c))
 102 #  define CURRENT_SYNTAX_TABLE gl_state.current_syntax_table
 103 #else
 104 #  define SYNTAX_ENTRY SYNTAX_ENTRY_INT
 105 #  define CURRENT_SYNTAX_TABLE current_buffer->syntax_table
 106 #endif
 107
 108 #define SYNTAX_ENTRY_INT(c)                                             \
 109   ((c) < CHAR_TABLE_SINGLE_BYTE_SLOTS                           \
 110    ? SYNTAX_ENTRY_FOLLOW_PARENT (CURRENT_SYNTAX_TABLE,  \
 111                                  (unsigned char) (c))           \
 112    : Faref (CURRENT_SYNTAX_TABLE, make_number ((c))))
 113
 114 /* Extract the information from the entry for character C
 115    in the current syntax table.  */
 116
 117 #ifdef __GNUC__
 118 #define SYNTAX(c)                                                       \
 119   ({ Lisp_Object temp;                                                  \
 120      temp = SYNTAX_ENTRY (c);                                           \
 121      (CONSP (temp)                                                      \
 122       ? (enum syntaxcode) (XINT (XCONS (temp)->car) & 0xff)             \
 123       : Swhitespace); })
 124
 125 #define SYNTAX_WITH_FLAGS(c)                                            \
 126   ({ Lisp_Object temp;                                                  \
 127      temp = SYNTAX_ENTRY (c);                                           \
 128      (CONSP (temp)                                                      \
 129       ? XINT (XCONS (temp)->car)                                        \
 130       : (int) Swhitespace); })
 131
 132 #define SYNTAX_MATCH(c)                                                 \
 133   ({ Lisp_Object temp;                                                  \
 134      temp = SYNTAX_ENTRY (c);                                           \
 135      (CONSP (temp)                                                      \
 136       ? XCONS (temp)->cdr                                               \
 137       : Qnil); })
 138 #else
 139 #define SYNTAX(c)                                                       \
 140   (syntax_temp = SYNTAX_ENTRY ((c)),                                    \
 141    (CONSP (syntax_temp)                                                 \
 142     ? (enum syntaxcode) (XINT (XCONS (syntax_temp)->car) & 0xff)        \
 143     : Swhitespace))
 144
 145 #define SYNTAX_WITH_FLAGS(c)                                            \
 146   (syntax_temp = SYNTAX_ENTRY ((c)),                                    \
 147    (CONSP (syntax_temp)                                                 \
 148     ? XINT (XCONS (syntax_temp)->car)                                   \
 149     : (int) Swhitespace))
 150
 151 #define SYNTAX_MATCH(c)                                                 \
 152   (syntax_temp = SYNTAX_ENTRY ((c)),                                    \
 153    (CONSP (syntax_temp)                                                 \
 154     ? XCONS (syntax_temp)->cdr                                          \
 155     : Qnil))
 156 #endif
 157
 158 /* Then there are six single-bit flags that have the following meanings:
 159   1. This character is the first of a two-character comment-start sequence.
 160   2. This character is the second of a two-character comment-start sequence.
 161   3. This character is the first of a two-character comment-end sequence.
 162   4. This character is the second of a two-character comment-end sequence.
 163   5. This character is a prefix, for backward-prefix-chars.
 164   Note that any two-character sequence whose first character has flag 1
 165   and whose second character has flag 2 will be interpreted as a comment start.
 166
 167   bit 6 is used to discriminate between two different comment styles.
 168   Languages such as C++ allow two orthogonal syntax start/end pairs
 169   and bit 6 is used to determine whether a comment-end or Scommentend
 170   ends style a or b.  Comment start sequences can start style a or b.
 171   Style a is always the default.
 172   */
 173
 174 #define SYNTAX_COMSTART_FIRST(c) ((SYNTAX_WITH_FLAGS (c) >> 16) & 1)
 175
 176 #define SYNTAX_COMSTART_SECOND(c) ((SYNTAX_WITH_FLAGS (c) >> 17) & 1)
 177
 178 #define SYNTAX_COMEND_FIRST(c) ((SYNTAX_WITH_FLAGS (c) >> 18) & 1)
 179
 180 #define SYNTAX_COMEND_SECOND(c) ((SYNTAX_WITH_FLAGS (c) >> 19) & 1)
 181
 182 #define SYNTAX_PREFIX(c) ((SYNTAX_WITH_FLAGS (c) >> 20) & 1)
 183
 184 /* extract the comment style bit from the syntax table entry */
 185 #define SYNTAX_COMMENT_STYLE(c) ((SYNTAX_WITH_FLAGS (c) >> 21) & 1)
 186
 187 /* This array, indexed by a character, contains the syntax code which that
 188  character signifies (as a char).  For example,
 189  (enum syntaxcode) syntax_spec_code['w'] is Sword.  */
 190
 191 extern unsigned char syntax_spec_code[0400];
 192
 193 /* Indexed by syntax code, give the letter that describes it.  */
 194
 195 extern char syntax_code_spec[16];
 196
 197 /* Make syntax table state (gl_state) good for POS, assuming it is
 198    currently good for a position before POS.  */
 199
 200 #define UPDATE_SYNTAX_TABLE_FORWARD(pos)                \
 201   ((pos) >= gl_state.e_property - gl_state.offset       \
 202    ? (update_syntax_table ((pos) + gl_state.offset, 1, 0, Qnil), 1) : 0)
 203
 204 /* Make syntax table state (gl_state) good for POS, assuming it is
 205    currently good for a position after POS.  */
 206
 207 #define UPDATE_SYNTAX_TABLE_BACKWARD(pos)               \
 208   ((pos) <= gl_state.b_property - gl_state.offset       \
 209    ? (update_syntax_table ((pos) + gl_state.offset, -1, 0, Qnil), 1) : 0)
 210
 211 /* Make syntax table good for POS.  */
 212
 213 #define UPDATE_SYNTAX_TABLE(pos)                                        \
 214   ((pos) <= gl_state.b_property - gl_state.offset                       \
 215    ? (update_syntax_table ((pos) + gl_state.offset, -1, 0, Qnil), 1)    \
 216    : ((pos) >= gl_state.e_property - gl_state.offset                    \
 217       ? (update_syntax_table ((pos) + gl_state.offset, 1, 0, Qnil), 1) : 0))
 218
 219 /* This macro should be called with FROM at the start of forward
 220    search, or after the last position of the backward search.  It
 221    makes sure that the first char is picked up with correct table, so
 222    one does not need to call UPDATE_SYNTAX_TABLE immediately after the
 223    call.
 224    Sign of COUNT gives the direction of the search.
 225  */
 226
 227 #define SETUP_SYNTAX_TABLE(from,count)                                  \
 228   gl_state.b_property = BEGV - 1;                                       \
 229   gl_state.e_property = ZV + 1;                                         \
 230   gl_state.use_global = 0;                                              \
 231   gl_state.offset = 0;                                                  \
 232   gl_state.current_syntax_table = current_buffer->syntax_table;         \
 233   if (parse_sexp_lookup_properties)                                     \
 234     update_syntax_table ((count) > 0 ? (from) : (from) - 1, (count),    \
 235                          1, Qnil);
 236
 237 /* Same as above, but in OBJECT.  If OBJECT is nil, use current buffer.
 238    If it is t, ignore properties altogether.
 239
 240    This is meant for regex.c to use.  For buffers, regex.c passes arguments
 241    to the UPDATE_SYNTAX_TABLE macros which are relative to BEGV.
 242    So if it is a buffer,a we set the offset field to BEGV.  */
 243
 244 #define SETUP_SYNTAX_TABLE_FOR_OBJECT(object, from, count)              \
 245   if (BUFFERP (object) || NILP (object))                                \
 246     {                                                                   \
 247       gl_state.b_property = BEGV - 1;                                   \
 248       gl_state.e_property = ZV;                                         \
 249       gl_state.offset = BEGV - 1;                                       \
 250     }                                                                   \
 251   else if (EQ (object, Qt))                                             \
 252     {                                                                   \
 253       gl_state.b_property = - 1;                                        \
 254       gl_state.e_property = 1500000000;                                 \
 255       gl_state.offset = 0;                                              \
 256     }                                                                   \
 257   else                                                                  \
 258     {                                                                   \
 259       gl_state.b_property = -1;                                         \
 260       gl_state.e_property = 1 + XSTRING (object)->size;                 \
 261       gl_state.offset = 0;                                              \
 262     }                                                                   \
 263   gl_state.use_global = 0;                                              \
 264   gl_state.current_syntax_table = current_buffer->syntax_table;         \
 265   if (parse_sexp_lookup_properties)                                     \
 266       update_syntax_table (count > 0 ? (from) : (from) - 1, count, 1, object);
 267
 268 struct gl_state_s
 269 {
 270   int start;                            /* Where to stop. */
 271   int stop;                             /* Where to stop. */
 272   int use_global;                       /* Whether to use global_code
 273                                            or c_s_t. */
 274   Lisp_Object global_code;              /* Syntax code of current char. */
 275   Lisp_Object current_syntax_table;     /* Syntax table for current pos. */
 276   Lisp_Object old_prop;                 /* Syntax-table prop at prev pos. */
 277   int b_property;                       /* Last index where c_s_t is
 278                                            not valid. */
 279   int e_property;                       /* First index where c_s_t is
 280                                            not valid. */
 281   INTERVAL forward_i;                   /* Where to start lookup on forward */
 282   INTERVAL backward_i;                  /* or backward movement.  The
 283                                            data in c_s_t is valid
 284                                            between these intervals,
 285                                            and possibly at the
 286                                            intervals too, depending
 287                                            on: */
 288   /* Offset for positions specified to UPDATE_SYNTAX_TABLE.  */
 289   int offset;
 290   char left_ok;
 291   char right_ok;
 292 };
 293
 294 extern struct gl_state_s gl_state;
 295 extern int parse_sexp_lookup_properties;
 296 extern INTERVAL interval_of P_ ((int, Lisp_Object));
 297
 298 extern int scan_words P_ ((int, int));