src/syntax.h

   1 /* Declarations having to do with GNU Emacs syntax tables.
   2    Copyright (C) 1985, 1993, 1994, 1997, 1998, 2001, 2002, 2003, 2004,
   3                  2005, 2006, 2007, 2008, 2009, 2010  Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software: you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation, either version 3 of the License, or
  10 (at your option) any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20
  21 extern Lisp_Object Qsyntax_table_p;
  22 extern void update_syntax_table (int, int, int, Lisp_Object);
  23
  24 /* The standard syntax table is stored where it will automatically
  25    be used in all new buffers.  */
  26 #define Vstandard_syntax_table buffer_defaults.syntax_table
  27
  28 /* A syntax table is a chartable whose elements are cons cells
  29    (CODE+FLAGS . MATCHING-CHAR).  MATCHING-CHAR can be nil if the char
  30    is not a kind of parenthesis.
  31
  32    The low 8 bits of CODE+FLAGS is a code, as follows:  */
  33
  34 enum syntaxcode
  35   {
  36     Swhitespace, /* for a whitespace character */
  37     Spunct,      /* for random punctuation characters */
  38     Sword,       /* for a word constituent */
  39     Ssymbol,     /* symbol constituent but not word constituent */
  40     Sopen,       /* for a beginning delimiter */
  41     Sclose,      /* for an ending delimiter */
  42     Squote,      /* for a prefix character like Lisp ' */
  43     Sstring,     /* for a string-grouping character like Lisp " */
  44     Smath,       /* for delimiters like $ in Tex.  */
  45     Sescape,     /* for a character that begins a C-style escape */
  46     Scharquote,  /* for a character that quotes the following character */
  47     Scomment,    /* for a comment-starting character */
  48     Sendcomment, /* for a comment-ending character */
  49     Sinherit,    /* use the standard syntax table for this character */
  50     Scomment_fence, /* Starts/ends comment which is delimited on the
  51                        other side by any char with the same syntaxcode.  */
  52     Sstring_fence,  /* Starts/ends string which is delimited on the
  53                        other side by any char with the same syntaxcode.  */
  54     Smax         /* Upper bound on codes that are meaningful */
  55   };
  56
  57 /* Set the syntax entry VAL for char C in table TABLE.  */
  58
  59 #define SET_RAW_SYNTAX_ENTRY(table, c, val)     \
  60   CHAR_TABLE_SET ((table), c, (val))
  61
  62 /* Set the syntax entry VAL for char-range RANGE in table TABLE.
  63    RANGE is a cons (FROM . TO) specifying the range of characters.  */
  64
  65 #define SET_RAW_SYNTAX_ENTRY_RANGE(table, range, val)   \
  66   Fset_char_table_range ((table), (range), (val))
  67
  68 /* SYNTAX_ENTRY fetches the information from the entry for character C
  69    in syntax table TABLE, or from globally kept data (gl_state).
  70    Does inheritance.  */
  71 /* CURRENT_SYNTAX_TABLE gives the syntax table valid for current
  72    position, it is either the buffer's syntax table, or syntax table
  73    found in text properties.  */
  74
  75 #ifdef SYNTAX_ENTRY_VIA_PROPERTY
  76 #  define SYNTAX_ENTRY(c)                                             \
  77     (gl_state.use_global ? gl_state.global_code : SYNTAX_ENTRY_INT (c))
  78 #  define CURRENT_SYNTAX_TABLE gl_state.current_syntax_table
  79 #else
  80 #  define SYNTAX_ENTRY SYNTAX_ENTRY_INT
  81 #  define CURRENT_SYNTAX_TABLE current_buffer->syntax_table
  82 #endif
  83
  84 #define SYNTAX_ENTRY_INT(c) CHAR_TABLE_REF (CURRENT_SYNTAX_TABLE, (c))
  85
  86 /* Extract the information from the entry for character C
  87    in the current syntax table.  */
  88
  89 #ifdef __GNUC__
  90 #define SYNTAX(c)                                                       \
  91   ({ Lisp_Object _syntax_temp;                                          \
  92      _syntax_temp = SYNTAX_ENTRY (c);                                   \
  93      (CONSP (_syntax_temp)                                              \
  94       ? (enum syntaxcode) (XINT (XCAR (_syntax_temp)) & 0xff)           \
  95       : Swhitespace); })
  96
  97 #define SYNTAX_WITH_FLAGS(c)                                            \
  98   ({ Lisp_Object _syntax_temp;                                          \
  99      _syntax_temp = SYNTAX_ENTRY (c);                                   \
 100      (CONSP (_syntax_temp)                                              \
 101       ? XINT (XCAR (_syntax_temp))                                      \
 102       : (int) Swhitespace); })
 103
 104 #define SYNTAX_MATCH(c)                                                 \
 105   ({ Lisp_Object _syntax_temp;                                          \
 106      _syntax_temp = SYNTAX_ENTRY (c);                                   \
 107      (CONSP (_syntax_temp)                                              \
 108       ? XCDR (_syntax_temp)                                             \
 109       : Qnil); })
 110 #else
 111 extern Lisp_Object syntax_temp;
 112 #define SYNTAX(c)                                                       \
 113   (syntax_temp = SYNTAX_ENTRY ((c)),                                    \
 114    (CONSP (syntax_temp)                                                 \
 115     ? (enum syntaxcode) (XINT (XCAR (syntax_temp)) & 0xff)      \
 116     : Swhitespace))
 117
 118 #define SYNTAX_WITH_FLAGS(c)                                            \
 119   (syntax_temp = SYNTAX_ENTRY ((c)),                                    \
 120    (CONSP (syntax_temp)                                                 \
 121     ? XINT (XCAR (syntax_temp))                                 \
 122     : (int) Swhitespace))
 123
 124 #define SYNTAX_MATCH(c)                                                 \
 125   (syntax_temp = SYNTAX_ENTRY ((c)),                                    \
 126    (CONSP (syntax_temp)                                                 \
 127     ? XCDR (syntax_temp)                                                \
 128     : Qnil))
 129 #endif
 130
 131 /* Then there are seven single-bit flags that have the following meanings:
 132   1. This character is the first of a two-character comment-start sequence.
 133   2. This character is the second of a two-character comment-start sequence.
 134   3. This character is the first of a two-character comment-end sequence.
 135   4. This character is the second of a two-character comment-end sequence.
 136   5. This character is a prefix, for backward-prefix-chars.
 137   6. see below
 138   7. This character is part of a nestable comment sequence.
 139   Note that any two-character sequence whose first character has flag 1
 140   and whose second character has flag 2 will be interpreted as a comment start.
 141
 142   bit 6 is used to discriminate between two different comment styles.
 143   Languages such as C++ allow two orthogonal syntax start/end pairs
 144   and bit 6 is used to determine whether a comment-end or Scommentend
 145   ends style a or b.  Comment start sequences can start style a or b.
 146   Style a is always the default.
 147   */
 148
 149 /* These macros extract a particular flag for a given character.  */
 150
 151 #define SYNTAX_COMSTART_FIRST(c) ((SYNTAX_WITH_FLAGS (c) >> 16) & 1)
 152
 153 #define SYNTAX_COMSTART_SECOND(c) ((SYNTAX_WITH_FLAGS (c) >> 17) & 1)
 154
 155 #define SYNTAX_COMEND_FIRST(c) ((SYNTAX_WITH_FLAGS (c) >> 18) & 1)
 156
 157 #define SYNTAX_COMEND_SECOND(c) ((SYNTAX_WITH_FLAGS (c) >> 19) & 1)
 158
 159 #define SYNTAX_PREFIX(c) ((SYNTAX_WITH_FLAGS (c) >> 20) & 1)
 160
 161 #define SYNTAX_COMMENT_STYLE(c) ((SYNTAX_WITH_FLAGS (c) >> 21) & 1)
 162
 163 #define SYNTAX_COMMENT_NESTED(c) ((SYNTAX_WITH_FLAGS (c) >> 22) & 1)
 164
 165 /* These macros extract specific flags from an integer
 166    that holds the syntax code and the flags.  */
 167
 168 #define SYNTAX_FLAGS_COMSTART_FIRST(flags) (((flags) >> 16) & 1)
 169
 170 #define SYNTAX_FLAGS_COMSTART_SECOND(flags) (((flags) >> 17) & 1)
 171
 172 #define SYNTAX_FLAGS_COMEND_FIRST(flags) (((flags) >> 18) & 1)
 173
 174 #define SYNTAX_FLAGS_COMEND_SECOND(flags) (((flags) >> 19) & 1)
 175
 176 #define SYNTAX_FLAGS_PREFIX(flags) (((flags) >> 20) & 1)
 177
 178 #define SYNTAX_FLAGS_COMMENT_STYLE(flags) (((flags) >> 21) & 1)
 179
 180 #define SYNTAX_FLAGS_COMMENT_NESTED(flags) (((flags) >> 22) & 1)
 181
 182 /* This array, indexed by a character, contains the syntax code which that
 183  character signifies (as a char).  For example,
 184  (enum syntaxcode) syntax_spec_code['w'] is Sword.  */
 185
 186 extern unsigned char syntax_spec_code[0400];
 187
 188 /* Indexed by syntax code, give the letter that describes it.  */
 189
 190 extern char syntax_code_spec[16];
 191
 192 /* Convert the byte offset BYTEPOS into a character position,
 193    for the object recorded in gl_state with SETUP_SYNTAX_TABLE_FOR_OBJECT.
 194
 195    The value is meant for use in the UPDATE_SYNTAX_TABLE... macros.
 196    These macros do nothing when parse_sexp_lookup_properties is 0,
 197    so we return 0 in that case, for speed.  */
 198
 199 #define SYNTAX_TABLE_BYTE_TO_CHAR(bytepos)                              \
 200   (! parse_sexp_lookup_properties                                       \
 201    ? 0                                                                  \
 202    : STRINGP (gl_state.object)                                          \
 203    ? string_byte_to_char (gl_state.object, (bytepos))                   \
 204    : BUFFERP (gl_state.object)                                          \
 205    ? buf_bytepos_to_charpos (XBUFFER (gl_state.object),                 \
 206                              (bytepos) + BUF_BEGV_BYTE (XBUFFER (gl_state.object)) - 1) - BUF_BEGV (XBUFFER (gl_state.object)) + 1      \
 207    : NILP (gl_state.object)                                             \
 208    ? BYTE_TO_CHAR ((bytepos) + BEGV_BYTE - 1) - BEGV + 1                \
 209    : (bytepos))
 210
 211 /* Make syntax table state (gl_state) good for CHARPOS, assuming it is
 212    currently good for a position before CHARPOS.  */
 213
 214 #define UPDATE_SYNTAX_TABLE_FORWARD(charpos)                    \
 215   (parse_sexp_lookup_properties                                 \
 216    && (charpos) >= gl_state.e_property                          \
 217    ? (update_syntax_table ((charpos) + gl_state.offset, 1, 0,   \
 218                            gl_state.object),                    \
 219       1)                                                        \
 220    : 0)
 221
 222 /* Make syntax table state (gl_state) good for CHARPOS, assuming it is
 223    currently good for a position after CHARPOS.  */
 224
 225 #define UPDATE_SYNTAX_TABLE_BACKWARD(charpos)                   \
 226   (parse_sexp_lookup_properties                                 \
 227    && (charpos) < gl_state.b_property                           \
 228    ? (update_syntax_table ((charpos) + gl_state.offset, -1, 0,  \
 229                            gl_state.object),                    \
 230       1)                                                        \
 231    : 0)
 232
 233 /* Make syntax table good for CHARPOS.  */
 234
 235 #define UPDATE_SYNTAX_TABLE(charpos)                            \
 236   (parse_sexp_lookup_properties                                 \
 237    && (charpos) < gl_state.b_property                           \
 238    ? (update_syntax_table ((charpos) + gl_state.offset, -1, 0,  \
 239                            gl_state.object),                    \
 240       1)                                                        \
 241    : (parse_sexp_lookup_properties                              \
 242       && (charpos) >= gl_state.e_property                       \
 243       ? (update_syntax_table ((charpos) + gl_state.offset, 1, 0,\
 244                               gl_state.object),                 \
 245          1)                                                     \
 246       : 0))
 247
 248 /* This macro sets up the buffer-global syntax table.  */
 249 #define SETUP_BUFFER_SYNTAX_TABLE()                                     \
 250 do                                                                      \
 251   {                                                                     \
 252     gl_state.use_global = 0;                                            \
 253     gl_state.current_syntax_table = current_buffer->syntax_table;       \
 254   } while (0)
 255
 256 /* This macro should be called with FROM at the start of forward
 257    search, or after the last position of the backward search.  It
 258    makes sure that the first char is picked up with correct table, so
 259    one does not need to call UPDATE_SYNTAX_TABLE immediately after the
 260    call.
 261    Sign of COUNT gives the direction of the search.
 262  */
 263
 264 #define SETUP_SYNTAX_TABLE(FROM, COUNT)                                 \
 265 do                                                                      \
 266   {                                                                     \
 267     SETUP_BUFFER_SYNTAX_TABLE ();                                       \
 268     gl_state.b_property = BEGV;                                         \
 269     gl_state.e_property = ZV + 1;                                       \
 270     gl_state.object = Qnil;                                             \
 271     gl_state.offset = 0;                                                \
 272     if (parse_sexp_lookup_properties)                                   \
 273       if ((COUNT) > 0 || (FROM) > BEGV)                                 \
 274         update_syntax_table ((COUNT) > 0 ? (FROM) : (FROM) - 1, (COUNT),\
 275                              1, Qnil);                                  \
 276   }                                                                     \
 277 while (0)
 278
 279 /* Same as above, but in OBJECT.  If OBJECT is nil, use current buffer.
 280    If it is t, ignore properties altogether.
 281
 282    This is meant for regex.c to use.  For buffers, regex.c passes arguments
 283    to the UPDATE_SYNTAX_TABLE macros which are relative to BEGV.
 284    So if it is a buffer, we set the offset field to BEGV.  */
 285
 286 #define SETUP_SYNTAX_TABLE_FOR_OBJECT(OBJECT, FROM, COUNT)              \
 287 do                                                                      \
 288   {                                                                     \
 289     SETUP_BUFFER_SYNTAX_TABLE ();                                       \
 290     gl_state.object = (OBJECT);                                         \
 291     if (BUFFERP (gl_state.object))                                      \
 292       {                                                                 \
 293         struct buffer *buf = XBUFFER (gl_state.object);                 \
 294         gl_state.b_property = 1;                                        \
 295         gl_state.e_property = BUF_ZV (buf) - BUF_BEGV (buf) + 1;        \
 296         gl_state.offset = BUF_BEGV (buf) - 1;                           \
 297       }                                                                 \
 298     else if (NILP (gl_state.object))                                    \
 299       {                                                                 \
 300         gl_state.b_property = 1;                                        \
 301         gl_state.e_property = ZV - BEGV + 1;                            \
 302         gl_state.offset = BEGV - 1;                                     \
 303       }                                                                 \
 304     else if (EQ (gl_state.object, Qt))                                  \
 305       {                                                                 \
 306         gl_state.b_property = 0;                                        \
 307         gl_state.e_property = 1500000000;                               \
 308         gl_state.offset = 0;                                            \
 309       }                                                                 \
 310     else                                                                \
 311       {                                                                 \
 312         gl_state.b_property = 0;                                        \
 313         gl_state.e_property = 1 + SCHARS (gl_state.object);             \
 314         gl_state.offset = 0;                                            \
 315       }                                                                 \
 316     if (parse_sexp_lookup_properties)                                   \
 317       update_syntax_table (((FROM) + gl_state.offset                    \
 318                             + (COUNT > 0 ? 0 :  -1)),                   \
 319                            COUNT, 1, gl_state.object);                  \
 320   }                                                                     \
 321 while (0)
 322
 323 struct gl_state_s
 324 {
 325   Lisp_Object object;                   /* The object we are scanning. */
 326   int start;                            /* Where to stop. */
 327   int stop;                             /* Where to stop. */
 328   int use_global;                       /* Whether to use global_code
 329                                            or c_s_t. */
 330   Lisp_Object global_code;              /* Syntax code of current char. */
 331   Lisp_Object current_syntax_table;     /* Syntax table for current pos. */
 332   Lisp_Object old_prop;                 /* Syntax-table prop at prev pos. */
 333   int b_property;                       /* First index where c_s_t is valid. */
 334   int e_property;                       /* First index where c_s_t is
 335                                            not valid. */
 336   INTERVAL forward_i;                   /* Where to start lookup on forward */
 337   INTERVAL backward_i;                  /* or backward movement.  The
 338                                            data in c_s_t is valid
 339                                            between these intervals,
 340                                            and possibly at the
 341                                            intervals too, depending
 342                                            on: */
 343   /* Offset for positions specified to UPDATE_SYNTAX_TABLE.  */
 344   int offset;
 345 };
 346
 347 extern struct gl_state_s gl_state;
 348 extern int parse_sexp_lookup_properties;
 349 extern INTERVAL interval_of (int, Lisp_Object);
 350
 351 extern int scan_words (int, int);
 352
 353 /* arch-tag: 28833cca-cd73-4741-8c85-a3111166a0e0
 354    (do not change this comment) */