src/casetab.c

   1 /* GNU Emacs routines to deal with case tables.
   2    Copyright (C) 1993, 1994, 2001, 2002, 2003, 2004,
   3                  2005, 2006, 2007, 2008  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, or (at your option)
  10 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; see the file COPYING.  If not, write to
  19 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22 /* Written by Howard Gayle.  */
  23
  24 #include <config.h>
  25 #include "lisp.h"
  26 #include "buffer.h"
  27 #include "character.h"
  28
  29 Lisp_Object Qcase_table_p, Qcase_table;
  30 Lisp_Object Vascii_downcase_table, Vascii_upcase_table;
  31 Lisp_Object Vascii_canon_table, Vascii_eqv_table;
  32
  33 /* Used as a temporary in DOWNCASE and other macros in lisp.h.  No
  34    need to mark it, since it is used only very temporarily.  */
  35 int case_temp1;
  36 Lisp_Object case_temp2;
  37
  38 static void set_canon ();
  39 static void set_identity ();
  40 static void shuffle ();
  41
  42 DEFUN ("case-table-p", Fcase_table_p, Scase_table_p, 1, 1, 0,
  43        doc: /* Return t if OBJECT is a case table.
  44 See `set-case-table' for more information on these data structures.  */)
  45      (object)
  46      Lisp_Object object;
  47 {
  48   Lisp_Object up, canon, eqv;
  49
  50   if (! CHAR_TABLE_P (object))
  51     return Qnil;
  52   if (! EQ (XCHAR_TABLE (object)->purpose, Qcase_table))
  53     return Qnil;
  54
  55   up = XCHAR_TABLE (object)->extras[0];
  56   canon = XCHAR_TABLE (object)->extras[1];
  57   eqv = XCHAR_TABLE (object)->extras[2];
  58
  59   return ((NILP (up) || CHAR_TABLE_P (up))
  60           && ((NILP (canon) && NILP (eqv))
  61               || (CHAR_TABLE_P (canon)
  62                   && (NILP (eqv) || CHAR_TABLE_P (eqv))))
  63           ? Qt : Qnil);
  64 }
  65
  66 static Lisp_Object
  67 check_case_table (obj)
  68      Lisp_Object obj;
  69 {
  70   CHECK_TYPE (!NILP (Fcase_table_p (obj)), Qcase_table_p, obj);
  71   return (obj);
  72 }
  73
  74 DEFUN ("current-case-table", Fcurrent_case_table, Scurrent_case_table, 0, 0, 0,
  75        doc: /* Return the case table of the current buffer.  */)
  76      ()
  77 {
  78   return current_buffer->downcase_table;
  79 }
  80
  81 DEFUN ("standard-case-table", Fstandard_case_table, Sstandard_case_table, 0, 0, 0,
  82        doc: /* Return the standard case table.
  83 This is the one used for new buffers.  */)
  84      ()
  85 {
  86   return Vascii_downcase_table;
  87 }
  88
  89 static Lisp_Object set_case_table ();
  90
  91 DEFUN ("set-case-table", Fset_case_table, Sset_case_table, 1, 1, 0,
  92        doc: /* Select a new case table for the current buffer.
  93 A case table is a char-table which maps characters
  94 to their lower-case equivalents.  It also has three \"extra\" slots
  95 which may be additional char-tables or nil.
  96 These slots are called UPCASE, CANONICALIZE and EQUIVALENCES.
  97 UPCASE maps each non-upper-case character to its upper-case equivalent.
  98  (The value in UPCASE for an upper-case character is never used.)
  99  If lower and upper case characters are in 1-1 correspondence,
 100  you may use nil and the upcase table will be deduced from DOWNCASE.
 101 CANONICALIZE maps each character to a canonical equivalent;
 102  any two characters that are related by case-conversion have the same
 103  canonical equivalent character; it may be nil, in which case it is
 104  deduced from DOWNCASE and UPCASE.
 105 EQUIVALENCES is a map that cyclicly permutes each equivalence class
 106  (of characters with the same canonical equivalent); it may be nil,
 107  in which case it is deduced from CANONICALIZE.  */)
 108      (table)
 109      Lisp_Object table;
 110 {
 111   return set_case_table (table, 0);
 112 }
 113
 114 DEFUN ("set-standard-case-table", Fset_standard_case_table, Sset_standard_case_table, 1, 1, 0,
 115        doc: /* Select a new standard case table for new buffers.
 116 See `set-case-table' for more info on case tables.  */)
 117      (table)
 118      Lisp_Object table;
 119 {
 120   return set_case_table (table, 1);
 121 }
 122
 123 static Lisp_Object
 124 set_case_table (table, standard)
 125      Lisp_Object table;
 126      int standard;
 127 {
 128   Lisp_Object up, canon, eqv;
 129
 130   check_case_table (table);
 131
 132   up = XCHAR_TABLE (table)->extras[0];
 133   canon = XCHAR_TABLE (table)->extras[1];
 134   eqv = XCHAR_TABLE (table)->extras[2];
 135
 136   if (NILP (up))
 137     {
 138       up = Fmake_char_table (Qcase_table, Qnil);
 139       map_char_table (set_identity, Qnil, table, up);
 140       map_char_table (shuffle, Qnil, table, up);
 141       XCHAR_TABLE (table)->extras[0] = up;
 142     }
 143
 144   if (NILP (canon))
 145     {
 146       canon = Fmake_char_table (Qcase_table, Qnil);
 147       XCHAR_TABLE (table)->extras[1] = canon;
 148       map_char_table (set_canon, Qnil, table, table);
 149     }
 150
 151   if (NILP (eqv))
 152     {
 153       eqv = Fmake_char_table (Qcase_table, Qnil);
 154       map_char_table (set_identity, Qnil, canon, eqv);
 155       map_char_table (shuffle, Qnil, canon, eqv);
 156       XCHAR_TABLE (table)->extras[2] = eqv;
 157     }
 158
 159   /* This is so set_image_of_range_1 in regex.c can find the EQV table.  */
 160   XCHAR_TABLE (canon)->extras[2] = eqv;
 161
 162   if (standard)
 163     {
 164       Vascii_downcase_table = table;
 165       Vascii_upcase_table = up;
 166       Vascii_canon_table = canon;
 167       Vascii_eqv_table = eqv;
 168     }
 169   else
 170     {
 171       current_buffer->downcase_table = table;
 172       current_buffer->upcase_table = up;
 173       current_buffer->case_canon_table = canon;
 174       current_buffer->case_eqv_table = eqv;
 175     }
 176
 177   return table;
 178 }
 179 \f
 180 /* The following functions are called in map_char_table.  */
 181
 182 /* Set CANON char-table element for characters in RANGE to a
 183    translated ELT by UP and DOWN char-tables.  This is done only when
 184    ELT is a character.  The char-tables CANON, UP, and DOWN are in
 185    CASE_TABLE.  */
 186
 187 static void
 188 set_canon (case_table, range, elt)
 189      Lisp_Object case_table, range, elt;
 190 {
 191   Lisp_Object up = XCHAR_TABLE (case_table)->extras[0];
 192   Lisp_Object canon = XCHAR_TABLE (case_table)->extras[1];
 193
 194   if (NATNUMP (elt))
 195     Fset_char_table_range (canon, range, Faref (case_table, Faref (up, elt)));
 196 }
 197
 198 /* Set elements of char-table TABLE for C to C itself.  C may be a
 199    cons specifying a character range.  In that case, set characters in
 200    that range to themselves.  This is done only when ELT is a
 201    character.  This is called in map_char_table.  */
 202
 203 static void
 204 set_identity (table, c, elt)
 205      Lisp_Object table, c, elt;
 206 {
 207   if (NATNUMP (elt))
 208     {
 209       int from, to;
 210
 211       if (CONSP (c))
 212         {
 213           from = XINT (XCAR (c));
 214           to = XINT (XCDR (c));
 215         }
 216       else
 217         from = to = XINT (c);
 218       for (; from <= to; from++)
 219         CHAR_TABLE_SET (table, from, make_number (from));
 220     }
 221 }
 222
 223 /* Permute the elements of TABLE (which is initially an identity
 224    mapping) so that it has one cycle for each equivalence class
 225    induced by the translation table on which map_char_table is
 226    operated.  */
 227
 228 static void
 229 shuffle (table, c, elt)
 230      Lisp_Object table, c, elt;
 231 {
 232   if (NATNUMP (elt))
 233     {
 234       Lisp_Object tem = Faref (table, elt);
 235       int from, to;
 236
 237       if (CONSP (c))
 238         {
 239           from = XINT (XCAR (c));
 240           to = XINT (XCDR (c));
 241         }
 242       else
 243         from = to = XINT (c);
 244
 245       for (; from <= to; from++)
 246         if (from != XINT (elt))
 247           {
 248             Faset (table, elt, make_number (from));
 249             Faset (table, make_number (from), tem);
 250           }
 251     }
 252 }
 253 \f
 254 void
 255 init_casetab_once ()
 256 {
 257   register int i;
 258   Lisp_Object down, up;
 259   Qcase_table = intern ("case-table");
 260   staticpro (&Qcase_table);
 261
 262   /* Intern this now in case it isn't already done.
 263      Setting this variable twice is harmless.
 264      But don't staticpro it here--that is done in alloc.c.  */
 265   Qchar_table_extra_slots = intern ("char-table-extra-slots");
 266
 267   /* Now we are ready to set up this property, so we can
 268      create char tables.  */
 269   Fput (Qcase_table, Qchar_table_extra_slots, make_number (3));
 270
 271   down = Fmake_char_table (Qcase_table, Qnil);
 272   Vascii_downcase_table = down;
 273   XCHAR_TABLE (down)->purpose = Qcase_table;
 274
 275   for (i = 0; i < 128; i++)
 276     {
 277       int c = (i >= 'A' && i <= 'Z') ? i + ('a' - 'A') : i;
 278       CHAR_TABLE_SET (down, i, make_number (c));
 279     }
 280
 281   XCHAR_TABLE (down)->extras[1] = Fcopy_sequence (down);
 282
 283   up = Fmake_char_table (Qcase_table, Qnil);
 284   XCHAR_TABLE (down)->extras[0] = up;
 285
 286   for (i = 0; i < 128; i++)
 287     {
 288       int c = ((i >= 'A' && i <= 'Z') ? i + ('a' - 'A')
 289                : ((i >= 'a' && i <= 'z') ? i + ('A' - 'a')
 290                   : i));;
 291       CHAR_TABLE_SET (up, i, make_number (c));
 292     }
 293
 294   XCHAR_TABLE (down)->extras[2] = Fcopy_sequence (up);
 295
 296   /* Fill in what isn't filled in.  */
 297   set_case_table (down, 1);
 298 }
 299
 300 void
 301 syms_of_casetab ()
 302 {
 303   Qcase_table_p = intern ("case-table-p");
 304   staticpro (&Qcase_table_p);
 305
 306   staticpro (&Vascii_canon_table);
 307   staticpro (&Vascii_downcase_table);
 308   staticpro (&Vascii_eqv_table);
 309   staticpro (&Vascii_upcase_table);
 310
 311   defsubr (&Scase_table_p);
 312   defsubr (&Scurrent_case_table);
 313   defsubr (&Sstandard_case_table);
 314   defsubr (&Sset_case_table);
 315   defsubr (&Sset_standard_case_table);
 316 }
 317
 318 /* arch-tag: e06388ad-99fe-40ec-ba67-9d010fcc4916
 319    (do not change this comment) */