src/syntax.h

   1 /* Declarations having to do with GNU Emacs syntax tables.
   2    Copyright (C) 1985, 93, 94, 97, 1998 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 any char with the same syntaxcode.  */
  53     Sstring_fence,  /* Starts/ends string which is delimited on the
  54                        other side by any 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,                               \
 113             make_number (COMPOSITE_CHAR_P (c)                   \
 114                          ? cmpchar_component ((c), 0, 1)        \
 115                          : (c))))
 116
 117 /* Extract the information from the entry for character C
 118    in the current syntax table.  */
 119
 120 #ifdef __GNUC__
 121 #define SYNTAX(c)                                                       \
 122   ({ Lisp_Object temp;                                                  \
 123      temp = SYNTAX_ENTRY (c);                                           \
 124      (CONSP (temp)                                                      \
 125       ? (enum syntaxcode) (XINT (XCAR (temp)) & 0xff)           \
 126       : Swhitespace); })
 127
 128 #define SYNTAX_WITH_FLAGS(c)                                            \
 129   ({ Lisp_Object temp;                                                  \
 130      temp = SYNTAX_ENTRY (c);                                           \
 131      (CONSP (temp)                                                      \
 132       ? XINT (XCAR (temp))                                      \
 133       : (int) Swhitespace); })
 134
 135 #define SYNTAX_MATCH(c)                                                 \
 136   ({ Lisp_Object temp;                                                  \
 137      temp = SYNTAX_ENTRY (c);                                           \
 138      (CONSP (temp)                                                      \
 139       ? XCDR (temp)                                             \
 140       : Qnil); })
 141 #else
 142 #define SYNTAX(c)                                                       \
 143   (syntax_temp = SYNTAX_ENTRY ((c)),                                    \
 144    (CONSP (syntax_temp)                                                 \
 145     ? (enum syntaxcode) (XINT (XCAR (syntax_temp)) & 0xff)      \
 146     : Swhitespace))
 147
 148 #define SYNTAX_WITH_FLAGS(c)                                            \
 149   (syntax_temp = SYNTAX_ENTRY ((c)),                                    \
 150    (CONSP (syntax_temp)                                                 \
 151     ? XINT (XCAR (syntax_temp))                                 \
 152     : (int) Swhitespace))
 153
 154 #define SYNTAX_MATCH(c)                                                 \
 155   (syntax_temp = SYNTAX_ENTRY ((c)),                                    \
 156    (CONSP (syntax_temp)                                                 \
 157     ? XCDR (syntax_temp)                                                \
 158     : Qnil))
 159 #endif
 160
 161 /* Then there are seven single-bit flags that have the following meanings:
 162   1. This character is the first of a two-character comment-start sequence.
 163   2. This character is the second of a two-character comment-start sequence.
 164   3. This character is the first of a two-character comment-end sequence.
 165   4. This character is the second of a two-character comment-end sequence.
 166   5. This character is a prefix, for backward-prefix-chars.
 167   6. see below
 168   7. This character is part of a nestable comment sequence.
 169   Note that any two-character sequence whose first character has flag 1
 170   and whose second character has flag 2 will be interpreted as a comment start.
 171
 172   bit 6 is used to discriminate between two different comment styles.
 173   Languages such as C++ allow two orthogonal syntax start/end pairs
 174   and bit 6 is used to determine whether a comment-end or Scommentend
 175   ends style a or b.  Comment start sequences can start style a or b.
 176   Style a is always the default.
 177   */
 178
 179 /* These macros extract a particular flag for a given character.  */
 180
 181 #define SYNTAX_COMSTART_FIRST(c) ((SYNTAX_WITH_FLAGS (c) >> 16) & 1)
 182
 183 #define SYNTAX_COMSTART_SECOND(c) ((SYNTAX_WITH_FLAGS (c) >> 17) & 1)
 184
 185 #define SYNTAX_COMEND_FIRST(c) ((SYNTAX_WITH_FLAGS (c) >> 18) & 1)
 186
 187 #define SYNTAX_COMEND_SECOND(c) ((SYNTAX_WITH_FLAGS (c) >> 19) & 1)
 188
 189 #define SYNTAX_PREFIX(c) ((SYNTAX_WITH_FLAGS (c) >> 20) & 1)
 190
 191 #define SYNTAX_COMMENT_STYLE(c) ((SYNTAX_WITH_FLAGS (c) >> 21) & 1)
 192
 193 #define SYNTAX_COMMENT_NESTED(c) ((SYNTAX_WITH_FLAGS (c) >> 22) & 1)
 194
 195 /* These macros extract specific flags from an integer
 196    that holds the syntax code and the flags.  */
 197
 198 #define SYNTAX_FLAGS_COMSTART_FIRST(flags) (((flags) >> 16) & 1)
 199
 200 #define SYNTAX_FLAGS_COMSTART_SECOND(flags) (((flags) >> 17) & 1)
 201
 202 #define SYNTAX_FLAGS_COMEND_FIRST(flags) (((flags) >> 18) & 1)
 203
 204 #define SYNTAX_FLAGS_COMEND_SECOND(flags) (((flags) >> 19) & 1)
 205
 206 #define SYNTAX_FLAGS_PREFIX(flags) (((flags) >> 20) & 1)
 207
 208 #define SYNTAX_FLAGS_COMMENT_STYLE(flags) (((flags) >> 21) & 1)
 209
 210 #define SYNTAX_FLAGS_COMMENT_NESTED(flags) (((flags) >> 22) & 1)
 211
 212 /* This array, indexed by a character, contains the syntax code which that
 213  character signifies (as a char).  For example,
 214  (enum syntaxcode) syntax_spec_code['w'] is Sword.  */
 215
 216 extern unsigned char syntax_spec_code[0400];
 217
 218 /* Indexed by syntax code, give the letter that describes it.  */
 219
 220 extern char syntax_code_spec[16];
 221
 222 /* Convert the byte offset BYTEPOS into a character position,
 223    for the object recorded in gl_state with SETUP_SYNTAX_TABLE_FOR_OBJECT.
 224
 225    The value is meant for use in the UPDATE_SYNTAX_TABLE... macros.
 226    These macros do nothing when parse_sexp_lookup_properties is 0,
 227    so we return 0 in that case, for speed.  */
 228
 229 #define SYNTAX_TABLE_BYTE_TO_CHAR(bytepos)                              \
 230   (! parse_sexp_lookup_properties                                       \
 231    ? 0                                                                  \
 232    : STRINGP (gl_state.object)                                          \
 233    ? string_byte_to_char (gl_state.object, (bytepos))                   \
 234    : BUFFERP (gl_state.object)                                          \
 235    ? buf_bytepos_to_charpos (XBUFFER (gl_state.object),                 \
 236                              (bytepos) + BUF_BEGV_BYTE (XBUFFER (gl_state.object)) - 1) - BUF_BEGV (XBUFFER (gl_state.object)) + 1      \
 237    : NILP (gl_state.object)                                             \
 238    ? BYTE_TO_CHAR ((bytepos) + BEGV_BYTE - 1) - BEGV + 1                \
 239    : (bytepos))
 240
 241 /* Make syntax table state (gl_state) good for CHARPOS, assuming it is
 242    currently good for a position before CHARPOS.  */
 243
 244 #define UPDATE_SYNTAX_TABLE_FORWARD(charpos)                    \
 245   (parse_sexp_lookup_properties                                 \
 246    && (charpos) >= gl_state.e_property                          \
 247    ? (update_syntax_table ((charpos) + gl_state.offset, 1, 0,   \
 248                            gl_state.object),                    \
 249       1)                                                        \
 250    : 0)
 251
 252 /* Make syntax table state (gl_state) good for CHARPOS, assuming it is
 253    currently good for a position after CHARPOS.  */
 254
 255 #define UPDATE_SYNTAX_TABLE_BACKWARD(charpos)                   \
 256   (parse_sexp_lookup_properties                                 \
 257    && (charpos) <= gl_state.b_property                          \
 258    ? (update_syntax_table ((charpos) + gl_state.offset, -1, 0,  \
 259                            gl_state.object),                    \
 260       1)                                                        \
 261    : 0)
 262
 263 /* Make syntax table good for CHARPOS.  */
 264
 265 #define UPDATE_SYNTAX_TABLE(charpos)                            \
 266   (parse_sexp_lookup_properties                                 \
 267    && (charpos) <= gl_state.b_property                          \
 268    ? (update_syntax_table ((charpos) + gl_state.offset, -1, 0,  \
 269                            gl_state.object),                    \
 270       1)                                                        \
 271    : (parse_sexp_lookup_properties                              \
 272       && (charpos) >= gl_state.e_property                       \
 273       ? (update_syntax_table ((charpos) + gl_state.offset, 1, 0,\
 274                               gl_state.object),                 \
 275          1)                                                     \
 276       : 0))
 277
 278 /* This macro should be called with FROM at the start of forward
 279    search, or after the last position of the backward search.  It
 280    makes sure that the first char is picked up with correct table, so
 281    one does not need to call UPDATE_SYNTAX_TABLE immediately after the
 282    call.
 283    Sign of COUNT gives the direction of the search.
 284  */
 285
 286 #define SETUP_SYNTAX_TABLE(FROM, COUNT)                                 \
 287 if (1)                                                                  \
 288   {                                                                     \
 289     gl_state.b_property = BEGV - 1;                                     \
 290     gl_state.e_property = ZV + 1;                                       \
 291     gl_state.object = Qnil;                                             \
 292     gl_state.use_global = 0;                                            \
 293     gl_state.offset = 0;                                                \
 294     gl_state.current_syntax_table = current_buffer->syntax_table;       \
 295     if (parse_sexp_lookup_properties)                                   \
 296       if ((COUNT) > 0 || (FROM) > BEGV)                                 \
 297         update_syntax_table ((COUNT) > 0 ? (FROM) : (FROM) - 1, (COUNT),\
 298                              1, Qnil);                                  \
 299   }                                                                     \
 300 else
 301
 302 /* Same as above, but in OBJECT.  If OBJECT is nil, use current buffer.
 303    If it is t, ignore properties altogether.
 304
 305    This is meant for regex.c to use.  For buffers, regex.c passes arguments
 306    to the UPDATE_SYNTAX_TABLE macros which are relative to BEGV.
 307    So if it is a buffer, we set the offset field to BEGV.  */
 308
 309 #define SETUP_SYNTAX_TABLE_FOR_OBJECT(OBJECT, FROM, COUNT)              \
 310 if (1)                                                                  \
 311   {                                                                     \
 312     gl_state.object = (OBJECT);                                         \
 313     if (BUFFERP (gl_state.object))                                      \
 314       {                                                                 \
 315         struct buffer *buf = XBUFFER (gl_state.object);                 \
 316         gl_state.b_property = 0;                                        \
 317         gl_state.e_property = BUF_ZV (buf) - BUF_BEGV (buf) + 1;        \
 318         gl_state.offset = BUF_BEGV (buf) - 1;                           \
 319       }                                                                 \
 320     else if (NILP (gl_state.object))                                    \
 321       {                                                                 \
 322         gl_state.b_property = 0;                                        \
 323         gl_state.e_property = ZV - BEGV + 1;                            \
 324         gl_state.offset = BEGV - 1;                                     \
 325       }                                                                 \
 326     else if (EQ (gl_state.object, Qt))                                  \
 327       {                                                                 \
 328         gl_state.b_property = - 1;                                      \
 329         gl_state.e_property = 1500000000;                               \
 330         gl_state.offset = 0;                                            \
 331       }                                                                 \
 332     else                                                                \
 333       {                                                                 \
 334         gl_state.b_property = -1;                                       \
 335         gl_state.e_property = 1 + XSTRING (gl_state.object)->size;      \
 336         gl_state.offset = 0;                                            \
 337       }                                                                 \
 338     gl_state.use_global = 0;                                            \
 339     gl_state.current_syntax_table = current_buffer->syntax_table;       \
 340     if (parse_sexp_lookup_properties)                                   \
 341       update_syntax_table (((FROM) + gl_state.offset                    \
 342                             + (COUNT > 0 ? 0 :  -1)),                   \
 343                            COUNT, 1, gl_state.object);                  \
 344   }                                                                     \
 345 else
 346
 347 struct gl_state_s
 348 {
 349   Lisp_Object object;                   /* The object we are scanning. */
 350   int start;                            /* Where to stop. */
 351   int stop;                             /* Where to stop. */
 352   int use_global;                       /* Whether to use global_code
 353                                            or c_s_t. */
 354   Lisp_Object global_code;              /* Syntax code of current char. */
 355   Lisp_Object current_syntax_table;     /* Syntax table for current pos. */
 356   Lisp_Object old_prop;                 /* Syntax-table prop at prev pos. */
 357   int b_property;                       /* Last index where c_s_t is
 358                                            not valid. */
 359   int e_property;                       /* First index where c_s_t is
 360                                            not valid. */
 361   INTERVAL forward_i;                   /* Where to start lookup on forward */
 362   INTERVAL backward_i;                  /* or backward movement.  The
 363                                            data in c_s_t is valid
 364                                            between these intervals,
 365                                            and possibly at the
 366                                            intervals too, depending
 367                                            on: */
 368   /* Offset for positions specified to UPDATE_SYNTAX_TABLE.  */
 369   int offset;
 370   char left_ok;
 371   char right_ok;
 372 };
 373
 374 extern struct gl_state_s gl_state;
 375 extern int parse_sexp_lookup_properties;
 376 extern INTERVAL interval_of P_ ((int, Lisp_Object));
 377
 378 extern int scan_words P_ ((int, int));