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.  */
  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
 131   check_case_table (table);
 132
 133   up = XCHAR_TABLE (table)->extras[0];
 134   canon = XCHAR_TABLE (table)->extras[1];
 135   eqv = XCHAR_TABLE (table)->extras[2];
 136
 137   if (NILP (up))
 138     {
 139       up = Fmake_char_table (Qcase_table, Qnil);
 140       map_char_table (set_identity, Qnil, table, up);
 141       map_char_table (shuffle, Qnil, table, up);
 142       XCHAR_TABLE (table)->extras[0] = up;
 143     }
 144
 145   if (NILP (canon))
 146     {
 147       canon = Fmake_char_table (Qcase_table, Qnil);
 148       XCHAR_TABLE (table)->extras[1] = canon;
 149       map_char_table (set_canon, Qnil, table, table);
 150     }
 151
 152   if (NILP (eqv))
 153     {
 154       eqv = Fmake_char_table (Qcase_table, Qnil);
 155       map_char_table (set_identity, Qnil, canon, eqv);
 156       map_char_table (shuffle, Qnil, canon, eqv);
 157       XCHAR_TABLE (table)->extras[2] = eqv;
 158     }
 159
 160   /* This is so set_image_of_range_1 in regex.c can find the EQV table.  */
 161   XCHAR_TABLE (canon)->extras[2] = eqv;
 162
 163   if (standard)
 164     {
 165       Vascii_downcase_table = table;
 166       Vascii_upcase_table = up;
 167       Vascii_canon_table = canon;
 168       Vascii_eqv_table = eqv;
 169     }
 170   else
 171     {
 172       current_buffer->downcase_table = table;
 173       current_buffer->upcase_table = up;
 174       current_buffer->case_canon_table = canon;
 175       current_buffer->case_eqv_table = eqv;
 176     }
 177
 178   return table;
 179 }
 180 \f
 181 /* The following functions are called in map_char_table.  */
 182
 183 /* Set CANON char-table element for characters in RANGE to a
 184    translated ELT by UP and DOWN char-tables.  This is done only when
 185    ELT is a character.  The char-tables CANON, UP, and DOWN are in
 186    CASE_TABLE.  */
 187
 188 static void
 189 set_canon (case_table, range, elt)
 190      Lisp_Object case_table, range, elt;
 191 {
 192   Lisp_Object up = XCHAR_TABLE (case_table)->extras[0];
 193   Lisp_Object canon = XCHAR_TABLE (case_table)->extras[1];
 194
 195   if (NATNUMP (elt))
 196     Fset_char_table_range (canon, range, Faref (case_table, Faref (up, elt)));
 197 }
 198
 199 /* Set elements of char-table TABLE for C to C itself.  C may be a
 200    cons specifying a character range.  In that case, set characters in
 201    that range to themselves.  This is done only when ELT is a
 202    character.  This is called in map_char_table.  */
 203
 204 static void
 205 set_identity (table, c, elt)
 206      Lisp_Object table, c, elt;
 207 {
 208   if (NATNUMP (elt))
 209     {
 210       int from, to;
 211
 212       if (CONSP (c))
 213         {
 214           from = XINT (XCAR (c));
 215           to = XINT (XCDR (c));
 216         }
 217       else
 218         from = to = XINT (c);
 219       for (; from <= to; from++)
 220         CHAR_TABLE_SET (table, from, make_number (from));
 221     }
 222 }
 223
 224 /* Permute the elements of TABLE (which is initially an identity
 225    mapping) so that it has one cycle for each equivalence class
 226    induced by the translation table on which map_char_table is
 227    operated.  */
 228
 229 static void
 230 shuffle (table, c, elt)
 231      Lisp_Object table, c, elt;
 232 {
 233   if (NATNUMP (elt))
 234     {
 235       Lisp_Object tem = Faref (table, elt);
 236       int from, to;
 237
 238       if (CONSP (c))
 239         {
 240           from = XINT (XCAR (c));
 241           to = XINT (XCDR (c));
 242         }
 243       else
 244         from = to = XINT (c);
 245
 246       for (; from <= to; from++)
 247         if (from != XINT (elt))
 248           {
 249             Faset (table, elt, make_number (from));
 250             Faset (table, make_number (from), tem);
 251           }
 252     }
 253 }
 254 \f
 255 void
 256 init_casetab_once ()
 257 {
 258   register int i;
 259   Lisp_Object down, up;
 260   Qcase_table = intern ("case-table");
 261   staticpro (&Qcase_table);
 262
 263   /* Intern this now in case it isn't already done.
 264      Setting this variable twice is harmless.
 265      But don't staticpro it here--that is done in alloc.c.  */
 266   Qchar_table_extra_slots = intern ("char-table-extra-slots");
 267
 268   /* Now we are ready to set up this property, so we can
 269      create char tables.  */
 270   Fput (Qcase_table, Qchar_table_extra_slots, make_number (3));
 271
 272   down = Fmake_char_table (Qcase_table, Qnil);
 273   Vascii_downcase_table = down;
 274   XCHAR_TABLE (down)->purpose = Qcase_table;
 275
 276   for (i = 0; i < 128; i++)
 277     {
 278       int c = (i >= 'A' && i <= 'Z') ? i + ('a' - 'A') : i;
 279       CHAR_TABLE_SET (down, i, make_number (c));
 280     }
 281
 282   XCHAR_TABLE (down)->extras[1] = Fcopy_sequence (down);
 283
 284   up = Fmake_char_table (Qcase_table, Qnil);
 285   XCHAR_TABLE (down)->extras[0] = up;
 286
 287   for (i = 0; i < 128; i++)
 288     {
 289       int c = ((i >= 'A' && i <= 'Z') ? i + ('a' - 'A')
 290                : ((i >= 'a' && i <= 'z') ? i + ('A' - 'a')
 291                   : i));;
 292       CHAR_TABLE_SET (up, i, make_number (c));
 293     }
 294
 295   XCHAR_TABLE (down)->extras[2] = Fcopy_sequence (up);
 296 }
 297
 298 void
 299 syms_of_casetab ()
 300 {
 301   Qcase_table_p = intern ("case-table-p");
 302   staticpro (&Qcase_table_p);
 303
 304   staticpro (&Vascii_canon_table);
 305   staticpro (&Vascii_downcase_table);
 306   staticpro (&Vascii_eqv_table);
 307   staticpro (&Vascii_upcase_table);
 308
 309   defsubr (&Scase_table_p);
 310   defsubr (&Scurrent_case_table);
 311   defsubr (&Sstandard_case_table);
 312   defsubr (&Sset_case_table);
 313   defsubr (&Sset_standard_case_table);
 314 }
 315
 316 /* arch-tag: e06388ad-99fe-40ec-ba67-9d010fcc4916
 317    (do not change this comment) */