src/syntax.h

   1 /* Declarations having to do with GNU Emacs syntax tables.
   2    Copyright (C) 1985, 1993 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20
  21 extern Lisp_Object Qsyntax_table_p;
  22 extern Lisp_Object Fsyntax_table_p (), Fsyntax_table (), Fset_syntax_table ();
  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 Lisp vector of length 0400, whose elements are integers.
  29
  30 The low 8 bits of the integer is a code, as follows:
  31 */
  32
  33 enum syntaxcode
  34   {
  35     Swhitespace, /* for a whitespace character */
  36     Spunct,      /* for random punctuation characters */
  37     Sword,       /* for a word constituent */
  38     Ssymbol,     /* symbol constituent but not word constituent */
  39     Sopen,       /* for a beginning delimiter */
  40     Sclose,      /* for an ending delimiter */
  41     Squote,      /* for a prefix character like Lisp ' */
  42     Sstring,     /* for a string-grouping character like Lisp " */
  43     Smath,       /* for delimiters like $ in Tex. */
  44     Sescape,     /* for a character that begins a C-style escape */
  45     Scharquote,  /* for a character that quotes the following character */
  46     Scomment,    /* for a comment-starting character */
  47     Sendcomment, /* for a comment-ending character */
  48     Sinherit,    /* use the standard syntax table for this character */
  49     Smax         /* Upper bound on codes that are meaningful */
  50   };
  51
  52 #define RAW_SYNTAX(table, c) \
  53   ((enum syntaxcode) (XINT (XVECTOR (table)->contents[(unsigned char) (c)]) & 0377))
  54
  55 #ifdef __GNUC__
  56 #define SYNTAX(c)                                               \
  57  ({ unsigned char character = c;                                \
  58     enum syntaxcode syntax                                      \
  59       = RAW_SYNTAX (current_buffer->syntax_table, character);   \
  60     if (syntax == Sinherit)                                     \
  61       syntax = RAW_SYNTAX (Vstandard_syntax_table, character);  \
  62     syntax; })
  63 #else
  64 #define SYNTAX(c)                                               \
  65  (RAW_SYNTAX (current_buffer->syntax_table, c) == Sinherit      \
  66   ? RAW_SYNTAX (Vstandard_syntax_table, c)                      \
  67   : RAW_SYNTAX (current_buffer->syntax_table, c))
  68 #endif
  69
  70 /* The next 8 bits of the number is a character,
  71  the matching delimiter in the case of Sopen or Sclose. */
  72
  73 #define RAW_SYNTAX_MATCH(table, c) \
  74   ((XINT (XVECTOR (table)->contents[(unsigned char) (c)]) >> 8) & 0377)
  75
  76 #ifdef __GNUC__
  77 #define SYNTAX_MATCH(c)                                                     \
  78  ({ unsigned char character = c;                                            \
  79     enum syntaxcode syntax                                                  \
  80       = RAW_SYNTAX (current_buffer->syntax_table, character);               \
  81     int matcher;                                                            \
  82     if (syntax == Sinherit)                                                 \
  83       matcher = RAW_SYNTAX_MATCH (Vstandard_syntax_table, character);       \
  84     else                                                                    \
  85       matcher = RAW_SYNTAX_MATCH (current_buffer->syntax_table, character); \
  86     syntax; })
  87 #else
  88 #define SYNTAX_MATCH(c)                                         \
  89  (RAW_SYNTAX (current_buffer->syntax_table, c) == Sinherit      \
  90   ? RAW_SYNTAX_MATCH (Vstandard_syntax_table, c)                        \
  91   : RAW_SYNTAX_MATCH (current_buffer->syntax_table, c))
  92 #endif
  93
  94 /* Then there are six single-bit flags that have the following meanings:
  95   1. This character is the first of a two-character comment-start sequence.
  96   2. This character is the second of a two-character comment-start sequence.
  97   3. This character is the first of a two-character comment-end sequence.
  98   4. This character is the second of a two-character comment-end sequence.
  99   5. This character is a prefix, for backward-prefix-chars.
 100   Note that any two-character sequence whose first character has flag 1
 101   and whose second character has flag 2 will be interpreted as a comment start.
 102
 103   bit 6 is used to discriminate between two different comment styles.
 104   Languages such as C++ allow two orthogonal syntax start/end pairs
 105   and bit 6 is used to determine whether a comment-end or Scommentend
 106   ends style a or b. Comment start sequences can start style a or b.
 107   Style a is always the default.
 108   */
 109
 110 #define SYNTAX_CHOOSE_TABLE(c)                                  \
 111  (RAW_SYNTAX (current_buffer->syntax_table, c) == Sinherit      \
 112   ? Vstandard_syntax_table : current_buffer->syntax_table)
 113
 114 #ifdef __GNUC__
 115
 116 #define SYNTAX_COMSTART_FIRST(c)                        \
 117   ({ unsigned char ch = c;                              \
 118      Lisp_Object table = SYNTAX_CHOOSE_TABLE (ch);      \
 119      (XINT (XVECTOR (table)->contents[ch]) >> 16) & 1;  \
 120    })
 121
 122 #define SYNTAX_COMSTART_SECOND(c) \
 123   ({ unsigned char ch = c;                              \
 124      Lisp_Object table = SYNTAX_CHOOSE_TABLE (ch);      \
 125      (XINT (XVECTOR (table)->contents[ch]) >> 17) & 1;  \
 126    })
 127
 128 #define SYNTAX_COMEND_FIRST(c) \
 129   ({ unsigned char ch = c;                              \
 130      Lisp_Object table = SYNTAX_CHOOSE_TABLE (ch);      \
 131      (XINT (XVECTOR (table)->contents[ch]) >> 18) & 1;  \
 132    })
 133
 134 #define SYNTAX_COMEND_SECOND(c) \
 135   ({ unsigned char ch = c;                              \
 136      Lisp_Object table = SYNTAX_CHOOSE_TABLE (ch);      \
 137      (XINT (XVECTOR (table)->contents[ch]) >> 19) & 1;  \
 138    })
 139
 140 #define SYNTAX_PREFIX(c) \
 141   ({ unsigned char ch = c;                              \
 142      Lisp_Object table = SYNTAX_CHOOSE_TABLE (ch);      \
 143      (XINT (XVECTOR (table)->contents[ch]) >> 20) & 1;  \
 144    })
 145
 146 /* extract the comment style bit from the syntax table entry */
 147 #define SYNTAX_COMMENT_STYLE(c) \
 148   ({ unsigned char ch = c;                              \
 149      Lisp_Object table = SYNTAX_CHOOSE_TABLE (ch);      \
 150      (XINT (XVECTOR (table)->contents[ch]) >> 21) & 1;  \
 151    })
 152
 153 #else
 154
 155 #define SYNTAX_COMSTART_FIRST(c) \
 156   ((XINT (XVECTOR (SYNTAX_CHOOSE_TABLE (c))->contents[(unsigned char) (c)]) >> 16) & 1)
 157
 158 #define SYNTAX_COMSTART_SECOND(c) \
 159   ((XINT (XVECTOR (SYNTAX_CHOOSE_TABLE (c))->contents[(unsigned char) (c)]) >> 17) & 1)
 160
 161 #define SYNTAX_COMEND_FIRST(c) \
 162   ((XINT (XVECTOR (SYNTAX_CHOOSE_TABLE (c))->contents[(unsigned char) (c)]) >> 18) & 1)
 163
 164 #define SYNTAX_COMEND_SECOND(c) \
 165   ((XINT (XVECTOR (SYNTAX_CHOOSE_TABLE (c))->contents[(unsigned char) (c)]) >> 19) & 1)
 166
 167 #define SYNTAX_PREFIX(c) \
 168   ((XINT (XVECTOR (SYNTAX_CHOOSE_TABLE (c))->contents[(unsigned char) (c)]) >> 20) & 1)
 169
 170 /* extract the comment style bit from the syntax table entry */
 171 #define SYNTAX_COMMENT_STYLE(c) \
 172   ((XINT (XVECTOR (SYNTAX_CHOOSE_TABLE (c))->contents[(unsigned char) (c)]) >> 21) & 1)
 173
 174 #endif
 175
 176 /* This array, indexed by a character, contains the syntax code which that
 177  character signifies (as a char).  For example,
 178  (enum syntaxcode) syntax_spec_code['w'] is Sword. */
 179
 180 extern unsigned char syntax_spec_code[0400];
 181
 182 /* Indexed by syntax code, give the letter that describes it. */
 183
 184 extern char syntax_code_spec[14];