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 extern void update_syntax_table_forward (ptrdiff_t, bool, Lisp_Object);
  25
  26 /* The standard syntax table is stored where it will automatically
  27    be used in all new buffers.  */
  28 #define Vstandard_syntax_table BVAR (&buffer_defaults, syntax_table)
  29
  30 /* A syntax table is a chartable whose elements are cons cells
  31    (CODE+FLAGS . MATCHING-CHAR).  MATCHING-CHAR can be nil if the char
  32    is not a kind of parenthesis.
  33
  34    The low 8 bits of CODE+FLAGS is a code, as follows:  */
  35
  36 enum syntaxcode
  37   {
  38     Swhitespace, /* for a whitespace character */
  39     Spunct,      /* for random punctuation characters */
  40     Sword,       /* for a word constituent */
  41     Ssymbol,     /* symbol constituent but not word constituent */
  42     Sopen,       /* for a beginning delimiter */
  43     Sclose,      /* for an ending delimiter */
  44     Squote,      /* for a prefix character like Lisp ' */
  45     Sstring,     /* for a string-grouping character like Lisp " */
  46     Smath,       /* for delimiters like $ in Tex.  */
  47     Sescape,     /* for a character that begins a C-style escape */
  48     Scharquote,  /* for a character that quotes the following character */
  49     Scomment,    /* for a comment-starting character */
  50     Sendcomment, /* for a comment-ending character */
  51     Sinherit,    /* use the standard syntax table for this character */
  52     Scomment_fence, /* Starts/ends comment which is delimited on the
  53                        other side by any char with the same syntaxcode.  */
  54     Sstring_fence,  /* Starts/ends string which is delimited on the
  55                        other side by any char with the same syntaxcode.  */
  56     Smax         /* Upper bound on codes that are meaningful.  */
  57   };
  58
  59
  60 struct gl_state_s
  61 {
  62   Lisp_Object object;                   /* The object we are scanning.  */
  63   ptrdiff_t start;                      /* Where to stop.  */
  64   ptrdiff_t stop;                       /* Where to stop.  */
  65   bool use_global;                      /* Whether to use global_code
  66                                            or c_s_t.  */
  67   Lisp_Object global_code;              /* Syntax code of current char.  */
  68   Lisp_Object current_syntax_table;     /* Syntax table for current pos.  */
  69   Lisp_Object old_prop;                 /* Syntax-table prop at prev pos.  */
  70   ptrdiff_t b_property;                 /* First index where c_s_t is valid.  */
  71   ptrdiff_t e_property;                 /* First index where c_s_t is
  72                                            not valid.  */
  73   bool e_property_truncated;            /* true if e_property if was truncated
  74                                            by parse_sexp_propertize_done.  */
  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 the current buffer's syntax table,
  90    or (if VIA_PROPERTY) from globally kept data (gl_state).
  91    Does inheritance.  */
  92
  93 INLINE Lisp_Object
  94 syntax_property_entry (int c, bool via_property)
  95 {
  96   if (via_property)
  97     return (gl_state.use_global
  98             ? gl_state.global_code
  99             : CHAR_TABLE_REF (gl_state.current_syntax_table, c));
 100   return CHAR_TABLE_REF (BVAR (current_buffer, syntax_table), c);
 101 }
 102 INLINE Lisp_Object
 103 SYNTAX_ENTRY (int c)
 104 {
 105   return syntax_property_entry (c, false);
 106 }
 107
 108 /* Extract the information from the entry for character C
 109    in the current syntax table.  */
 110
 111 INLINE int
 112 syntax_property_with_flags (int c, bool via_property)
 113 {
 114   Lisp_Object ent = syntax_property_entry (c, via_property);
 115   return CONSP (ent) ? XINT (XCAR (ent)) : Swhitespace;
 116 }
 117 INLINE int
 118 SYNTAX_WITH_FLAGS (int c)
 119 {
 120   return syntax_property_with_flags (c, false);
 121 }
 122
 123 INLINE enum syntaxcode
 124 syntax_property (int c, bool via_property)
 125 {
 126   return syntax_property_with_flags (c, via_property) & 0xff;
 127 }
 128 INLINE enum syntaxcode
 129 SYNTAX (int c)
 130 {
 131   return syntax_property (c, false);
 132 }
 133
 134
 135 /* Whether the syntax of the character C has the prefix flag set.  */
 136 extern bool syntax_prefix_flag_p (int c);
 137
 138 /* This array, indexed by a character less than 256, contains the
 139    syntax code which that character signifies (as an unsigned char).
 140    For example, syntax_spec_code['w'] == Sword.  */
 141
 142 extern unsigned char const syntax_spec_code[0400];
 143
 144 /* Indexed by syntax code, give the letter that describes it.  */
 145
 146 extern char const syntax_code_spec[16];
 147
 148 /* Convert the byte offset BYTEPOS into a character position,
 149    for the object recorded in gl_state with SETUP_SYNTAX_TABLE_FOR_OBJECT.
 150
 151    The value is meant for use in code that does nothing when
 152    parse_sexp_lookup_properties is false, so return 0 in that case,
 153    for speed.  */
 154
 155 INLINE ptrdiff_t
 156 SYNTAX_TABLE_BYTE_TO_CHAR (ptrdiff_t bytepos)
 157 {
 158   return (! parse_sexp_lookup_properties
 159           ? 0
 160           : STRINGP (gl_state.object)
 161           ? string_byte_to_char (gl_state.object, bytepos)
 162           : BUFFERP (gl_state.object)
 163           ? ((buf_bytepos_to_charpos
 164               (XBUFFER (gl_state.object),
 165                (bytepos + BUF_BEGV_BYTE (XBUFFER (gl_state.object)) - 1)))
 166              - BUF_BEGV (XBUFFER (gl_state.object)) + 1)
 167           : NILP (gl_state.object)
 168           ? BYTE_TO_CHAR (bytepos + BEGV_BYTE - 1) - BEGV + 1
 169           : bytepos);
 170 }
 171
 172 /* Make syntax table state (gl_state) good for CHARPOS, assuming it is
 173    currently good for a position before CHARPOS.  */
 174
 175 INLINE void
 176 UPDATE_SYNTAX_TABLE_FORWARD (ptrdiff_t charpos)
 177 { /* Performs just-in-time syntax-propertization.  */
 178   if (parse_sexp_lookup_properties && charpos >= gl_state.e_property)
 179     update_syntax_table_forward (charpos + gl_state.offset,
 180                                  false, gl_state.object);
 181 }
 182
 183 /* Make syntax table state (gl_state) good for CHARPOS, assuming it is
 184    currently good for a position after CHARPOS.  */
 185
 186 INLINE void
 187 UPDATE_SYNTAX_TABLE_BACKWARD (ptrdiff_t charpos)
 188 {
 189   if (parse_sexp_lookup_properties && charpos < gl_state.b_property)
 190     update_syntax_table (charpos + gl_state.offset, -1, false, gl_state.object);
 191 }
 192
 193 /* Make syntax table good for CHARPOS.  */
 194
 195 INLINE void
 196 UPDATE_SYNTAX_TABLE (ptrdiff_t charpos)
 197 {
 198   UPDATE_SYNTAX_TABLE_BACKWARD (charpos);
 199   UPDATE_SYNTAX_TABLE_FORWARD (charpos);
 200 }
 201
 202 /* Set up the buffer-global syntax table.  */
 203
 204 INLINE void
 205 SETUP_BUFFER_SYNTAX_TABLE (void)
 206 {
 207   gl_state.use_global = false;
 208   gl_state.e_property_truncated = false;
 209   gl_state.current_syntax_table = BVAR (current_buffer, syntax_table);
 210 }
 211
 212 extern ptrdiff_t scan_words (ptrdiff_t, EMACS_INT);
 213 extern void SETUP_SYNTAX_TABLE_FOR_OBJECT (Lisp_Object, ptrdiff_t, ptrdiff_t);
 214
 215 INLINE_HEADER_END