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