src/casetab.c

   1 /* GNU Emacs routines to deal with case tables.
   2    Copyright (C) 1993, 1994, 2002, 2003, 2004,
   3                  2005 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 2, 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 iff 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   register Lisp_Object tem;
  71
  72   while (tem = Fcase_table_p (obj), NILP (tem))
  73     obj = wrong_type_argument (Qcase_table_p, obj);
  74   return (obj);
  75 }
  76
  77 DEFUN ("current-case-table", Fcurrent_case_table, Scurrent_case_table, 0, 0, 0,
  78        doc: /* Return the case table of the current buffer.  */)
  79      ()
  80 {
  81   return current_buffer->downcase_table;
  82 }
  83
  84 DEFUN ("standard-case-table", Fstandard_case_table, Sstandard_case_table, 0, 0, 0,
  85        doc: /* Return the standard case table.
  86 This is the one used for new buffers.  */)
  87      ()
  88 {
  89   return Vascii_downcase_table;
  90 }
  91
  92 static Lisp_Object set_case_table ();
  93
  94 DEFUN ("set-case-table", Fset_case_table, Sset_case_table, 1, 1, 0,
  95        doc: /* Select a new case table for the current buffer.
  96 A case table is a char-table which maps characters
  97 to their lower-case equivalents.  It also has three \"extra\" slots
  98 which may be additional char-tables or nil.
  99 These slots are called UPCASE, CANONICALIZE and EQUIVALENCES.
 100 UPCASE maps each character to its upper-case equivalent;
 101  if lower and upper case characters are in 1-1 correspondence,
 102  you may use nil and the upcase table will be deduced from DOWNCASE.
 103 CANONICALIZE maps each character to a canonical equivalent;
 104  any two characters that are related by case-conversion have the same
 105  canonical equivalent character; it may be nil, in which case it is
 106  deduced from DOWNCASE and UPCASE.
 107 EQUIVALENCES is a map that cyclicly permutes each equivalence class
 108  (of characters with the same canonical equivalent); it may be nil,
 109  in which case it is deduced from CANONICALIZE.  */)
 110      (table)
 111      Lisp_Object table;
 112 {
 113   return set_case_table (table, 0);
 114 }
 115
 116 DEFUN ("set-standard-case-table", Fset_standard_case_table, Sset_standard_case_table, 1, 1, 0,
 117        doc: /* Select a new standard case table for new buffers.
 118 See `set-case-table' for more info on case tables.  */)
 119      (table)
 120      Lisp_Object table;
 121 {
 122   return set_case_table (table, 1);
 123 }
 124
 125 static Lisp_Object
 126 set_case_table (table, standard)
 127      Lisp_Object table;
 128      int standard;
 129 {
 130   Lisp_Object up, canon, eqv;
 131
 132   check_case_table (table);
 133
 134   up = XCHAR_TABLE (table)->extras[0];
 135   canon = XCHAR_TABLE (table)->extras[1];
 136   eqv = XCHAR_TABLE (table)->extras[2];
 137
 138   if (NILP (up))
 139     {
 140       up = Fmake_char_table (Qcase_table, Qnil);
 141       map_char_table (set_identity, Qnil, table, up);
 142       map_char_table (shuffle, Qnil, table, up);
 143       XCHAR_TABLE (table)->extras[0] = up;
 144     }
 145
 146   if (NILP (canon))
 147     {
 148       canon = Fmake_char_table (Qcase_table, Qnil);
 149       XCHAR_TABLE (table)->extras[1] = canon;
 150       map_char_table (set_canon, Qnil, table, table);
 151     }
 152
 153   if (NILP (eqv))
 154     {
 155       eqv = Fmake_char_table (Qcase_table, Qnil);
 156       map_char_table (set_identity, Qnil, canon, eqv);
 157       map_char_table (shuffle, Qnil, canon, eqv);
 158       XCHAR_TABLE (table)->extras[2] = eqv;
 159     }
 160
 161   /* This is so set_image_of_range_1 in regex.c can find the EQV table.  */
 162   XCHAR_TABLE (canon)->extras[2] = eqv;
 163
 164   if (standard)
 165     {
 166       Vascii_downcase_table = table;
 167       Vascii_upcase_table = up;
 168       Vascii_canon_table = canon;
 169       Vascii_eqv_table = eqv;
 170     }
 171   else
 172     {
 173       current_buffer->downcase_table = table;
 174       current_buffer->upcase_table = up;
 175       current_buffer->case_canon_table = canon;
 176       current_buffer->case_eqv_table = eqv;
 177     }
 178
 179   return table;
 180 }
 181 \f
 182 /* The following functions are called in map_char_table.  */
 183
 184 /* Set CANON char-table element for characters in RANGE to a
 185    translated ELT by UP and DOWN char-tables.  This is done only when
 186    ELT is a character.  The char-tables CANON, UP, and DOWN are in
 187    CASE_TABLE.  */
 188
 189 static void
 190 set_canon (case_table, range, elt)
 191      Lisp_Object case_table, range, elt;
 192 {
 193   Lisp_Object up = XCHAR_TABLE (case_table)->extras[0];
 194   Lisp_Object canon = XCHAR_TABLE (case_table)->extras[1];
 195
 196   if (NATNUMP (elt))
 197     Fset_char_table_range (canon, range, Faref (case_table, Faref (up, elt)));
 198 }
 199
 200 /* Set elements of char-table TABLE for C to C itself.  C may be a
 201    cons specifying a character range.  In that case, set characters in
 202    that range to themselves.  This is done only when ELT is a
 203    character.  This is called in map_char_table.  */
 204
 205 static void
 206 set_identity (table, c, elt)
 207      Lisp_Object table, c, elt;
 208 {
 209   if (NATNUMP (elt))
 210     {
 211       int from, to;
 212
 213       if (CONSP (c))
 214         {
 215           from = XINT (XCAR (c));
 216           to = XINT (XCDR (c));
 217         }
 218       else
 219         from = to = XINT (c);
 220       for (; from <= to; from++)
 221         CHAR_TABLE_SET (table, from, make_number (from));
 222     }
 223 }
 224
 225 /* Permute the elements of TABLE (which is initially an identity
 226    mapping) so that it has one cycle for each equivalence class
 227    induced by the translation table on which map_char_table is
 228    operated.  */
 229
 230 static void
 231 shuffle (table, c, elt)
 232      Lisp_Object table, c, elt;
 233 {
 234   if (NATNUMP (elt))
 235     {
 236       Lisp_Object tem = Faref (table, elt);
 237       int from, to;
 238
 239       if (CONSP (c))
 240         {
 241           from = XINT (XCAR (c));
 242           to = XINT (XCDR (c));
 243         }
 244       else
 245         from = to = XINT (c);
 246
 247       for (; from <= to; from++)
 248         if (from != XINT (elt))
 249           {
 250             Faset (table, elt, make_number (from));
 251             Faset (table, make_number (from), tem);
 252           }
 253     }
 254 }
 255 \f
 256 void
 257 init_casetab_once ()
 258 {
 259   register int i;
 260   Lisp_Object down, up;
 261   Qcase_table = intern ("case-table");
 262   staticpro (&Qcase_table);
 263
 264   /* Intern this now in case it isn't already done.
 265      Setting this variable twice is harmless.
 266      But don't staticpro it here--that is done in alloc.c.  */
 267   Qchar_table_extra_slots = intern ("char-table-extra-slots");
 268
 269   /* Now we are ready to set up this property, so we can
 270      create char tables.  */
 271   Fput (Qcase_table, Qchar_table_extra_slots, make_number (3));
 272
 273   down = Fmake_char_table (Qcase_table, Qnil);
 274   Vascii_downcase_table = down;
 275   XCHAR_TABLE (down)->purpose = Qcase_table;
 276
 277   for (i = 0; i < 128; i++)
 278     {
 279       int c = (i >= 'A' && i <= 'Z') ? i + ('a' - 'A') : i;
 280       CHAR_TABLE_SET (down, i, make_number (c));
 281     }
 282
 283   XCHAR_TABLE (down)->extras[1] = Fcopy_sequence (down);
 284
 285   up = Fmake_char_table (Qcase_table, Qnil);
 286   XCHAR_TABLE (down)->extras[0] = up;
 287
 288   for (i = 0; i < 128; i++)
 289     {
 290       int c = ((i >= 'A' && i <= 'Z') ? i + ('a' - 'A')
 291                : ((i >= 'a' && i <= 'z') ? i + ('A' - 'a')
 292                   : i));;
 293       CHAR_TABLE_SET (up, i, make_number (c));
 294     }
 295
 296   XCHAR_TABLE (down)->extras[2] = Fcopy_sequence (up);
 297 }
 298
 299 void
 300 syms_of_casetab ()
 301 {
 302   Qcase_table_p = intern ("case-table-p");
 303   staticpro (&Qcase_table_p);
 304
 305   staticpro (&Vascii_canon_table);
 306   staticpro (&Vascii_downcase_table);
 307   staticpro (&Vascii_eqv_table);
 308   staticpro (&Vascii_upcase_table);
 309
 310   defsubr (&Scase_table_p);
 311   defsubr (&Scurrent_case_table);
 312   defsubr (&Sstandard_case_table);
 313   defsubr (&Sset_case_table);
 314   defsubr (&Sset_standard_case_table);
 315 }
 316
 317 /* arch-tag: e06388ad-99fe-40ec-ba67-9d010fcc4916
 318    (do not change this comment) */