src/syntax.h

   1 /* Declarations having to do with GNU Emacs syntax tables.
   2
   3 Copyright (C) 1985, 1993-1994, 1997-1998, 2001-2015 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
  23 extern void update_syntax_table (ptrdiff_t, EMACS_INT, bool, 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 BVAR (&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
  59 struct gl_state_s
  60 {
  61   Lisp_Object object;                   /* The object we are scanning. */
  62   ptrdiff_t start;                      /* Where to stop. */
  63   ptrdiff_t stop;                       /* Where to stop. */
  64   bool use_global;                      /* Whether to use global_code
  65                                            or c_s_t. */
  66   Lisp_Object global_code;              /* Syntax code of current char. */
  67   Lisp_Object current_syntax_table;     /* Syntax table for current pos. */
  68   Lisp_Object old_prop;                 /* Syntax-table prop at prev pos. */
  69   ptrdiff_t b_property;                 /* First index where c_s_t is valid. */
  70   ptrdiff_t e_property;                 /* First index where c_s_t is
  71                                            not valid. */
  72   INTERVAL forward_i;                   /* Where to start lookup on forward */
  73   INTERVAL backward_i;                  /* or backward movement.  The
  74                                            data in c_s_t is valid
  75                                            between these intervals,
  76                                            and possibly at the
  77                                            intervals too, depending
  78                                            on: */
  79   /* Offset for positions specified to UPDATE_SYNTAX_TABLE.  */
  80   ptrdiff_t offset;
  81 };
  82
  83 extern struct gl_state_s gl_state;
  84
  85 /* Fetch the information from the entry for character C
  86    in the current buffer's syntax table,
  87    or (if VIA_PROPERTY) from globally kept data (gl_state).
  88    Does inheritance.  */
  89
  90 INLINE Lisp_Object
  91 syntax_property_entry (int c, bool via_property)
  92 {
  93   if (via_property)
  94     return (gl_state.use_global
  95             ? gl_state.global_code
  96             : CHAR_TABLE_REF (gl_state.current_syntax_table, c));
  97   return CHAR_TABLE_REF (BVAR (current_buffer, syntax_table), c);
  98 }
  99 INLINE Lisp_Object
 100 SYNTAX_ENTRY (int c)
 101 {
 102   return syntax_property_entry (c, false);
 103 }
 104
 105 /* Extract the information from the entry for character C
 106    in the current syntax table.  */
 107
 108 INLINE int
 109 syntax_property_with_flags (int c, bool via_property)
 110 {
 111   Lisp_Object ent = syntax_property_entry (c, via_property);
 112   return CONSP (ent) ? XINT (XCAR (ent)) : Swhitespace;
 113 }
 114 INLINE int
 115 SYNTAX_WITH_FLAGS (int c)
 116 {
 117   return syntax_property_with_flags (c, false);
 118 }
 119
 120 INLINE enum syntaxcode
 121 syntax_property (int c, bool via_property)
 122 {
 123   return syntax_property_with_flags (c, via_property) & 0xff;
 124 }
 125 INLINE enum syntaxcode
 126 SYNTAX (int c)
 127 {
 128   return syntax_property (c, false);
 129 }
 130
 131
 132 /* Whether the syntax of the character C has the prefix flag set.  */
 133 extern bool syntax_prefix_flag_p (int c);
 134
 135 /* This array, indexed by a character less than 256, contains the
 136    syntax code which that character signifies (as an unsigned char).
 137    For example, syntax_spec_code['w'] == Sword.  */
 138
 139 extern unsigned char const syntax_spec_code[0400];
 140
 141 /* Indexed by syntax code, give the letter that describes it.  */
 142
 143 extern char const syntax_code_spec[16];
 144
 145 /* Convert the byte offset BYTEPOS into a character position,
 146    for the object recorded in gl_state with SETUP_SYNTAX_TABLE_FOR_OBJECT.
 147
 148    The value is meant for use in code that does nothing when
 149    parse_sexp_lookup_properties is false, so return 0 in that case,
 150    for speed.  */
 151
 152 INLINE ptrdiff_t
 153 SYNTAX_TABLE_BYTE_TO_CHAR (ptrdiff_t bytepos)
 154 {
 155   return (! parse_sexp_lookup_properties
 156           ? 0
 157           : STRINGP (gl_state.object)
 158           ? string_byte_to_char (gl_state.object, bytepos)
 159           : BUFFERP (gl_state.object)
 160           ? ((buf_bytepos_to_charpos
 161               (XBUFFER (gl_state.object),
 162                (bytepos + BUF_BEGV_BYTE (XBUFFER (gl_state.object)) - 1)))
 163              - BUF_BEGV (XBUFFER (gl_state.object)) + 1)
 164           : NILP (gl_state.object)
 165           ? BYTE_TO_CHAR (bytepos + BEGV_BYTE - 1) - BEGV + 1
 166           : bytepos);
 167 }
 168
 169 /* Make syntax table state (gl_state) good for CHARPOS, assuming it is
 170    currently good for a position before CHARPOS.  */
 171
 172 INLINE void
 173 UPDATE_SYNTAX_TABLE_FORWARD (ptrdiff_t charpos)
 174 {
 175   if (parse_sexp_lookup_properties && charpos >= gl_state.e_property)
 176     update_syntax_table (charpos + gl_state.offset, 1, false, gl_state.object);
 177 }
 178
 179 /* Make syntax table state (gl_state) good for CHARPOS, assuming it is
 180    currently good for a position after CHARPOS.  */
 181
 182 INLINE void
 183 UPDATE_SYNTAX_TABLE_BACKWARD (ptrdiff_t charpos)
 184 {
 185   if (parse_sexp_lookup_properties && charpos < gl_state.b_property)
 186     update_syntax_table (charpos + gl_state.offset, -1, false, gl_state.object);
 187 }
 188
 189 /* Make syntax table good for CHARPOS.  */
 190
 191 INLINE void
 192 UPDATE_SYNTAX_TABLE (ptrdiff_t charpos)
 193 {
 194   UPDATE_SYNTAX_TABLE_BACKWARD (charpos);
 195   UPDATE_SYNTAX_TABLE_FORWARD (charpos);
 196 }
 197
 198 /* Set up the buffer-global syntax table.  */
 199
 200 INLINE void
 201 SETUP_BUFFER_SYNTAX_TABLE (void)
 202 {
 203   gl_state.use_global = false;
 204   gl_state.current_syntax_table = BVAR (current_buffer, syntax_table);
 205 }
 206
 207 extern ptrdiff_t scan_words (ptrdiff_t, EMACS_INT);
 208 extern void SETUP_SYNTAX_TABLE_FOR_OBJECT (Lisp_Object, ptrdiff_t, ptrdiff_t);
 209
 210 INLINE_HEADER_END