code.delx.au - gnu-emacs/blob - src/casetab.c

   1 /* GNU Emacs routines to deal with case tables.
   2    Copyright (C) 1993, 1994 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 2, 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, Inc., 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 /* Written by Howard Gayle.  See chartab.c for details. */
  22
  23 #include <config.h>
  24 #include "lisp.h"
  25 #include "buffer.h"
  26 #include "character.h"
  27
  28 Lisp_Object Qcase_table_p, Qcase_table;
  29 Lisp_Object Vascii_downcase_table, Vascii_upcase_table;
  30 Lisp_Object Vascii_canon_table, Vascii_eqv_table;
  31
  32 /* Used as a temporary in DOWNCASE and other macros in lisp.h.  No
  33    need to mark it, since it is used only very temporarily.  */
  34 int case_temp1;
  35 Lisp_Object case_temp2;
  36
  37 static void set_canon ();
  38 static void set_identity ();
  39 static void shuffle ();
  40
  41 DEFUN ("case-table-p", Fcase_table_p, Scase_table_p, 1, 1, 0,
  42        doc: /* Return t iff OBJECT is a case table.
  43 See `set-case-table' for more information on these data structures.  */)
  44      (object)
  45      Lisp_Object object;
  46 {
  47   Lisp_Object up, canon, eqv;
  48
  49   if (! CHAR_TABLE_P (object))
  50     return Qnil;
  51   if (! EQ (XCHAR_TABLE (object)->purpose, Qcase_table))
  52     return Qnil;
  53
  54   up = XCHAR_TABLE (object)->extras[0];
  55   canon = XCHAR_TABLE (object)->extras[1];
  56   eqv = XCHAR_TABLE (object)->extras[2];
  57
  58   return ((NILP (up) || CHAR_TABLE_P (up))
  59           && ((NILP (canon) && NILP (eqv))
  60               || (CHAR_TABLE_P (canon)
  61                   && (NILP (eqv) || CHAR_TABLE_P (eqv))))
  62           ? Qt : Qnil);
  63 }
  64
  65 static Lisp_Object
  66 check_case_table (obj)
  67      Lisp_Object obj;
  68 {
  69   register Lisp_Object tem;
  70
  71   while (tem = Fcase_table_p (obj), NILP (tem))
  72     obj = wrong_type_argument (Qcase_table_p, obj);
  73   return (obj);
  74 }
  75
  76 DEFUN ("current-case-table", Fcurrent_case_table, Scurrent_case_table, 0, 0, 0,
  77        doc: /* Return the case table of the current buffer.  */)
  78      ()
  79 {
  80   return current_buffer->downcase_table;
  81 }
  82
  83 DEFUN ("standard-case-table", Fstandard_case_table, Sstandard_case_table, 0, 0, 0,
  84        doc: /* Return the standard case table.
  85 This is the one used for new buffers.  */)
  86      ()
  87 {
  88   return Vascii_downcase_table;
  89 }
  90
  91 static Lisp_Object set_case_table ();
  92
  93 DEFUN ("set-case-table", Fset_case_table, Sset_case_table, 1, 1, 0,
  94        doc: /* Select a new case table for the current buffer.
  95 A case table is a char-table which maps characters
  96 to their lower-case equivalents.  It also has three \"extra\" slots
  97 which may be additional char-tables or nil.
  98 These slots are called UPCASE, CANONICALIZE and EQUIVALENCES.
  99 UPCASE maps each character to its upper-case equivalent;
 100  if lower and upper case characters are in 1-1 correspondence,
 101  you may use nil and the upcase table will be deduced from DOWNCASE.
 102 CANONICALIZE maps each character to a canonical equivalent;
 103  any two characters that are related by case-conversion have the same
 104  canonical equivalent character; it may be nil, in which case it is
 105  deduced from DOWNCASE and UPCASE.
 106 EQUIVALENCES is a map that cyclicly permutes each equivalence class
 107  (of characters with the same canonical equivalent); it may be nil,
 108  in which case it is deduced from CANONICALIZE.  */)
 109      (table)
 110      Lisp_Object table;
 111 {
 112   return set_case_table (table, 0);
 113 }
 114
 115 DEFUN ("set-standard-case-table", Fset_standard_case_table, Sset_standard_case_table, 1, 1, 0,
 116        doc: /* Select a new standard case table for new buffers.
 117 See `set-case-table' for more info on case tables.  */)
 118      (table)
 119      Lisp_Object table;
 120 {
 121   return set_case_table (table, 1);
 122 }
 123
 124 static Lisp_Object
 125 set_case_table (table, standard)
 126      Lisp_Object table;
 127      int standard;
 128 {
 129   Lisp_Object up, canon, eqv;
 130   Lisp_Object indices[3];
 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     Vascii_downcase_table = table;
 166   else
 167     {
 168       current_buffer->downcase_table = table;
 169       current_buffer->upcase_table = up;
 170       current_buffer->case_canon_table = canon;
 171       current_buffer->case_eqv_table = eqv;
 172     }
 173
 174   return table;
 175 }
 176 \f
 177 /* The following functions are called in map_char_table.  */
 178
 179 /* Set CANON char-table element for characters in RANGE to a
 180    translated ELT by UP and DOWN char-tables.  This is done only when
 181    ELT is a character.  The char-tables CANON, UP, and DOWN are in
 182    CASE_TABLE.  */
 183
 184 static void
 185 set_canon (case_table, range, elt)
 186      Lisp_Object case_table, range, elt;
 187 {
 188   Lisp_Object up = XCHAR_TABLE (case_table)->extras[0];
 189   Lisp_Object canon = XCHAR_TABLE (case_table)->extras[1];
 190
 191   if (NATNUMP (elt))
 192     Fset_char_table_range (canon, range, Faref (case_table, Faref (up, elt)));
 193 }
 194
 195 /* Set elements of char-table TABLE for C to C itself.  C may be a
 196    cons specifying a character range.  In that case, set characters in
 197    that range to themselves.  This is done only when ELT is a
 198    character.  This is called in map_char_table.  */
 199
 200 static void
 201 set_identity (table, c, elt)
 202      Lisp_Object table, c, elt;
 203 {
 204   if (NATNUMP (elt))
 205     {
 206       int from, to;
 207
 208       if (CONSP (c))
 209         {
 210           from = XINT (XCAR (c));
 211           to = XINT (XCDR (c));
 212         }
 213       else
 214         from = to = XINT (c);
 215       for (; from <= to; from++)
 216         CHAR_TABLE_SET (table, from, make_number (from));
 217     }
 218 }
 219
 220 /* Permute the elements of TABLE (which is initially an identity
 221    mapping) so that it has one cycle for each equivalence class
 222    induced by the translation table on which map_char_table is
 223    operated.  */
 224
 225 static void
 226 shuffle (table, c, elt)
 227      Lisp_Object table, c, elt;
 228 {
 229   if (NATNUMP (elt))
 230     {
 231       Lisp_Object tem = Faref (table, elt);
 232       int from, to;
 233
 234       if (CONSP (c))
 235         {
 236           from = XINT (XCAR (c));
 237           to = XINT (XCDR (c));
 238         }
 239       else
 240         from = to = XINT (c);
 241
 242       for (; from <= to; from++)
 243         if (from != XINT (elt))
 244           {
 245             Faset (table, elt, make_number (from));
 246             Faset (table, make_number (from), tem);
 247           }
 248     }
 249 }
 250 \f
 251 void
 252 init_casetab_once ()
 253 {
 254   register int i;
 255   Lisp_Object down, up;
 256   Qcase_table = intern ("case-table");
 257   staticpro (&Qcase_table);
 258
 259   /* Intern this now in case it isn't already done.
 260      Setting this variable twice is harmless.
 261      But don't staticpro it here--that is done in alloc.c.  */
 262   Qchar_table_extra_slots = intern ("char-table-extra-slots");
 263
 264   /* Now we are ready to set up this property, so we can
 265      create char tables.  */
 266   Fput (Qcase_table, Qchar_table_extra_slots, make_number (3));
 267
 268   down = Fmake_char_table (Qcase_table, Qnil);
 269   Vascii_downcase_table = down;
 270   XCHAR_TABLE (down)->purpose = Qcase_table;
 271
 272   for (i = 0; i < 128; i++)
 273     {
 274       int c = (i >= 'A' && i <= 'Z') ? i + ('a' - 'A') : i;
 275       CHAR_TABLE_SET (down, i, make_number (c));
 276     }
 277
 278   XCHAR_TABLE (down)->extras[1] = Fcopy_sequence (down);
 279
 280   up = Fmake_char_table (Qcase_table, Qnil);
 281   XCHAR_TABLE (down)->extras[0] = up;
 282
 283   for (i = 0; i < 128; i++)
 284     {
 285       int c = ((i >= 'A' && i <= 'Z') ? i + ('a' - 'A')
 286                : ((i >= 'a' && i <= 'z') ? i + ('A' - 'a')
 287                   : i));;
 288       CHAR_TABLE_SET (up, i, make_number (c));
 289     }
 290
 291   XCHAR_TABLE (down)->extras[2] = Fcopy_sequence (up);
 292 }
 293
 294 void
 295 syms_of_casetab ()
 296 {
 297   Qcase_table_p = intern ("case-table-p");
 298   staticpro (&Qcase_table_p);
 299
 300   staticpro (&Vascii_canon_table);
 301   staticpro (&Vascii_downcase_table);
 302   staticpro (&Vascii_eqv_table);
 303   staticpro (&Vascii_upcase_table);
 304
 305   defsubr (&Scase_table_p);
 306   defsubr (&Scurrent_case_table);
 307   defsubr (&Sstandard_case_table);
 308   defsubr (&Sset_case_table);
 309   defsubr (&Sset_standard_case_table);
 310 }