src/syntax.h

   1 /* Declarations having to do with GNU Emacs syntax tables.
   2
   3 Copyright (C) 1985, 1993-1994, 1997-1998, 2001-2013 Free Software
   4 Foundation, Inc.
   5
   6 This file is part of GNU Emacs.
   7
   8 GNU Emacs is free software: you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation, either version 3 of the License, or
  11 (at your option) any later version.
  12
  13 GNU Emacs is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 INLINE_HEADER_BEGIN
  22 #ifndef SYNTAX_INLINE
  23 # define SYNTAX_INLINE INLINE
  24 #endif
  25
  26 extern void update_syntax_table (ptrdiff_t, EMACS_INT, bool, Lisp_Object);
  27
  28 /* The standard syntax table is stored where it will automatically
  29    be used in all new buffers.  */
  30 #define Vstandard_syntax_table BVAR (&buffer_defaults, syntax_table)
  31
  32 /* A syntax table is a chartable whose elements are cons cells
  33    (CODE+FLAGS . MATCHING-CHAR).  MATCHING-CHAR can be nil if the char
  34    is not a kind of parenthesis.
  35
  36    The low 8 bits of CODE+FLAGS is a code, as follows:  */
  37
  38 enum syntaxcode
  39   {
  40     Swhitespace, /* for a whitespace character */
  41     Spunct,      /* for random punctuation characters */
  42     Sword,       /* for a word constituent */
  43     Ssymbol,     /* symbol constituent but not word constituent */
  44     Sopen,       /* for a beginning delimiter */
  45     Sclose,      /* for an ending delimiter */
  46     Squote,      /* for a prefix character like Lisp ' */
  47     Sstring,     /* for a string-grouping character like Lisp " */
  48     Smath,       /* for delimiters like $ in Tex.  */
  49     Sescape,     /* for a character that begins a C-style escape */
  50     Scharquote,  /* for a character that quotes the following character */
  51     Scomment,    /* for a comment-starting character */
  52     Sendcomment, /* for a comment-ending character */
  53     Sinherit,    /* use the standard syntax table for this character */
  54     Scomment_fence, /* Starts/ends comment which is delimited on the
  55                        other side by any char with the same syntaxcode.  */
  56     Sstring_fence,  /* Starts/ends string which is delimited on the
  57                        other side by any char with the same syntaxcode.  */
  58     Smax         /* Upper bound on codes that are meaningful */
  59   };
  60
  61
  62 struct gl_state_s
  63 {
  64   Lisp_Object object;                   /* The object we are scanning. */
  65   ptrdiff_t start;                      /* Where to stop. */
  66   ptrdiff_t stop;                       /* Where to stop. */
  67   bool use_global;                      /* Whether to use global_code
  68                                            or c_s_t. */
  69   Lisp_Object global_code;              /* Syntax code of current char. */
  70   Lisp_Object current_syntax_table;     /* Syntax table for current pos. */
  71   Lisp_Object old_prop;                 /* Syntax-table prop at prev pos. */
  72   ptrdiff_t b_property;                 /* First index where c_s_t is valid. */
  73   ptrdiff_t e_property;                 /* First index where c_s_t is
  74                                            not valid. */
  75   INTERVAL forward_i;                   /* Where to start lookup on forward */
  76   INTERVAL backward_i;                  /* or backward movement.  The
  77                                            data in c_s_t is valid
  78                                            between these intervals,
  79                                            and possibly at the
  80                                            intervals too, depending
  81                                            on: */
  82   /* Offset for positions specified to UPDATE_SYNTAX_TABLE.  */
  83   ptrdiff_t offset;
  84 };
  85
  86 extern struct gl_state_s gl_state;
  87
  88 /* Fetch the information from the entry for character C
  89    in syntax table TABLE, or from globally kept data (gl_state).
  90    Does inheritance.  */
  91
  92 SYNTAX_INLINE Lisp_Object
  93 SYNTAX_ENTRY (int c)
  94 {
  95 #ifdef SYNTAX_ENTRY_VIA_PROPERTY
  96   return (gl_state.use_global
  97           ? gl_state.global_code
  98           : CHAR_TABLE_REF (gl_state.current_syntax_table, c));
  99 #else
 100   return CHAR_TABLE_REF (BVAR (current_buffer, syntax_table), c);
 101 #endif
 102 }
 103
 104 /* Extract the information from the entry for character C
 105    in the current syntax table.  */
 106
 107 SYNTAX_INLINE int
 108 SYNTAX_WITH_FLAGS (int c)
 109 {
 110   Lisp_Object ent = SYNTAX_ENTRY (c);
 111   return CONSP (ent) ? XINT (XCAR (ent)) : Swhitespace;
 112 }
 113
 114 SYNTAX_INLINE enum syntaxcode
 115 SYNTAX (int c)
 116 {
 117   return SYNTAX_WITH_FLAGS (c) & 0xff;
 118 }
 119
 120
 121 /* Whether the syntax of the character C has the prefix flag set.  */
 122 extern bool syntax_prefix_flag_p (int c);
 123
 124 /* This array, indexed by a character less than 256, contains the
 125    syntax code which that character signifies (as an unsigned char).
 126    For example, syntax_spec_code['w'] == Sword.  */
 127
 128 extern unsigned char const syntax_spec_code[0400];
 129
 130 /* Indexed by syntax code, give the letter that describes it.  */
 131
 132 extern char const syntax_code_spec[16];
 133
 134 /* Convert the byte offset BYTEPOS into a character position,
 135    for the object recorded in gl_state with SETUP_SYNTAX_TABLE_FOR_OBJECT.
 136
 137    The value is meant for use in code that does nothing when
 138    parse_sexp_lookup_properties is 0, so return 0 in that case, for speed.  */
 139
 140 SYNTAX_INLINE ptrdiff_t
 141 SYNTAX_TABLE_BYTE_TO_CHAR (ptrdiff_t bytepos)
 142 {
 143   return (! parse_sexp_lookup_properties
 144           ? 0
 145           : STRINGP (gl_state.object)
 146           ? string_byte_to_char (gl_state.object, bytepos)
 147           : BUFFERP (gl_state.object)
 148           ? ((buf_bytepos_to_charpos
 149               (XBUFFER (gl_state.object),
 150                (bytepos + BUF_BEGV_BYTE (XBUFFER (gl_state.object)) - 1)))
 151              - BUF_BEGV (XBUFFER (gl_state.object)) + 1)
 152           : NILP (gl_state.object)
 153           ? BYTE_TO_CHAR (bytepos + BEGV_BYTE - 1) - BEGV + 1
 154           : bytepos);
 155 }
 156
 157 /* Make syntax table state (gl_state) good for CHARPOS, assuming it is
 158    currently good for a position before CHARPOS.  */
 159
 160 SYNTAX_INLINE void
 161 UPDATE_SYNTAX_TABLE_FORWARD (ptrdiff_t charpos)
 162 {
 163   if (parse_sexp_lookup_properties && charpos >= gl_state.e_property)
 164     update_syntax_table (charpos + gl_state.offset, 1, 0, gl_state.object);
 165 }
 166
 167 /* Make syntax table state (gl_state) good for CHARPOS, assuming it is
 168    currently good for a position after CHARPOS.  */
 169
 170 SYNTAX_INLINE void
 171 UPDATE_SYNTAX_TABLE_BACKWARD (ptrdiff_t charpos)
 172 {
 173   if (parse_sexp_lookup_properties && charpos < gl_state.b_property)
 174     update_syntax_table (charpos + gl_state.offset, -1, 0, gl_state.object);
 175 }
 176
 177 /* Make syntax table good for CHARPOS.  */
 178
 179 SYNTAX_INLINE void
 180 UPDATE_SYNTAX_TABLE (ptrdiff_t charpos)
 181 {
 182   UPDATE_SYNTAX_TABLE_BACKWARD (charpos);
 183   UPDATE_SYNTAX_TABLE_FORWARD (charpos);
 184 }
 185
 186 /* Set up the buffer-global syntax table.  */
 187
 188 SYNTAX_INLINE void
 189 SETUP_BUFFER_SYNTAX_TABLE (void)
 190 {
 191   gl_state.use_global = 0;
 192   gl_state.current_syntax_table = BVAR (current_buffer, syntax_table);
 193 }
 194
 195 extern ptrdiff_t scan_words (ptrdiff_t, EMACS_INT);
 196 extern void SETUP_SYNTAX_TABLE_FOR_OBJECT (Lisp_Object, ptrdiff_t, ptrdiff_t);
 197
 198 INLINE_HEADER_END