src/casetab.c

   1 /* GNU Emacs routines to deal with case tables.
   2    Copyright (C) 1993, 1994, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
   3                  2008, 2009, 2010  Free Software Foundation, Inc.
   4
   5 Author: Howard Gayle
   6
   7 This file is part of GNU Emacs.
   8
   9 GNU Emacs is free software: you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation, either version 3 of the License, or
  12 (at your option) any later version.
  13
  14 GNU Emacs is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include <config.h>
  23 #include <setjmp.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 if 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   CHECK_TYPE (!NILP (Fcase_table_p (obj)), Qcase_table_p, obj);
  70   return (obj);
  71 }
  72
  73 DEFUN ("current-case-table", Fcurrent_case_table, Scurrent_case_table, 0, 0, 0,
  74        doc: /* Return the case table of the current buffer.  */)
  75      ()
  76 {
  77   return current_buffer->downcase_table;
  78 }
  79
  80 DEFUN ("standard-case-table", Fstandard_case_table, Sstandard_case_table, 0, 0, 0,
  81        doc: /* Return the standard case table.
  82 This is the one used for new buffers.  */)
  83      ()
  84 {
  85   return Vascii_downcase_table;
  86 }
  87
  88 static Lisp_Object set_case_table ();
  89
  90 DEFUN ("set-case-table", Fset_case_table, Sset_case_table, 1, 1, 0,
  91        doc: /* Select a new case table for the current buffer.
  92 A case table is a char-table which maps characters
  93 to their lower-case equivalents.  It also has three \"extra\" slots
  94 which may be additional char-tables or nil.
  95 These slots are called UPCASE, CANONICALIZE and EQUIVALENCES.
  96 UPCASE maps each non-upper-case character to its upper-case equivalent.
  97  (The value in UPCASE for an upper-case character is never used.)
  98  If lower and upper case characters are in 1-1 correspondence,
  99  you may use nil and the upcase table will be deduced from DOWNCASE.
 100 CANONICALIZE maps each character to a canonical equivalent;
 101  any two characters that are related by case-conversion have the same
 102  canonical equivalent character; it may be nil, in which case it is
 103  deduced from DOWNCASE and UPCASE.
 104 EQUIVALENCES is a map that cyclicly permutes each equivalence class
 105  (of characters with the same canonical equivalent); it may be nil,
 106  in which case it is deduced from CANONICALIZE.  */)
 107      (table)
 108      Lisp_Object table;
 109 {
 110   return set_case_table (table, 0);
 111 }
 112
 113 DEFUN ("set-standard-case-table", Fset_standard_case_table, Sset_standard_case_table, 1, 1, 0,
 114        doc: /* Select a new standard case table for new buffers.
 115 See `set-case-table' for more info on case tables.  */)
 116      (table)
 117      Lisp_Object table;
 118 {
 119   return set_case_table (table, 1);
 120 }
 121
 122 static Lisp_Object
 123 set_case_table (table, standard)
 124      Lisp_Object table;
 125      int standard;
 126 {
 127   Lisp_Object up, canon, eqv;
 128
 129   check_case_table (table);
 130
 131   up = XCHAR_TABLE (table)->extras[0];
 132   canon = XCHAR_TABLE (table)->extras[1];
 133   eqv = XCHAR_TABLE (table)->extras[2];
 134
 135   if (NILP (up))
 136     {
 137       up = Fmake_char_table (Qcase_table, Qnil);
 138       map_char_table (set_identity, Qnil, table, up);
 139       map_char_table (shuffle, Qnil, table, up);
 140       XCHAR_TABLE (table)->extras[0] = up;
 141     }
 142
 143   if (NILP (canon))
 144     {
 145       canon = Fmake_char_table (Qcase_table, Qnil);
 146       XCHAR_TABLE (table)->extras[1] = canon;
 147       map_char_table (set_canon, Qnil, table, table);
 148     }
 149
 150   if (NILP (eqv))
 151     {
 152       eqv = Fmake_char_table (Qcase_table, Qnil);
 153       map_char_table (set_identity, Qnil, canon, eqv);
 154       map_char_table (shuffle, Qnil, canon, eqv);
 155       XCHAR_TABLE (table)->extras[2] = eqv;
 156     }
 157
 158   /* This is so set_image_of_range_1 in regex.c can find the EQV table.  */
 159   XCHAR_TABLE (canon)->extras[2] = eqv;
 160
 161   if (standard)
 162     {
 163       Vascii_downcase_table = table;
 164       Vascii_upcase_table = up;
 165       Vascii_canon_table = canon;
 166       Vascii_eqv_table = eqv;
 167     }
 168   else
 169     {
 170       current_buffer->downcase_table = table;
 171       current_buffer->upcase_table = up;
 172       current_buffer->case_canon_table = canon;
 173       current_buffer->case_eqv_table = eqv;
 174     }
 175
 176   return table;
 177 }
 178 \f
 179 /* The following functions are called in map_char_table.  */
 180
 181 /* Set CANON char-table element for characters in RANGE to a
 182    translated ELT by UP and DOWN char-tables.  This is done only when
 183    ELT is a character.  The char-tables CANON, UP, and DOWN are in
 184    CASE_TABLE.  */
 185
 186 static void
 187 set_canon (case_table, range, elt)
 188      Lisp_Object case_table, range, elt;
 189 {
 190   Lisp_Object up = XCHAR_TABLE (case_table)->extras[0];
 191   Lisp_Object canon = XCHAR_TABLE (case_table)->extras[1];
 192
 193   if (NATNUMP (elt))
 194     Fset_char_table_range (canon, range, Faref (case_table, Faref (up, elt)));
 195 }
 196
 197 /* Set elements of char-table TABLE for C to C itself.  C may be a
 198    cons specifying a character range.  In that case, set characters in
 199    that range to themselves.  This is done only when ELT is a
 200    character.  This is called in map_char_table.  */
 201
 202 static void
 203 set_identity (table, c, elt)
 204      Lisp_Object table, c, elt;
 205 {
 206   if (NATNUMP (elt))
 207     {
 208       int from, to;
 209
 210       if (CONSP (c))
 211         {
 212           from = XINT (XCAR (c));
 213           to = XINT (XCDR (c));
 214         }
 215       else
 216         from = to = XINT (c);
 217       for (; from <= to; from++)
 218         CHAR_TABLE_SET (table, from, make_number (from));
 219     }
 220 }
 221
 222 /* Permute the elements of TABLE (which is initially an identity
 223    mapping) so that it has one cycle for each equivalence class
 224    induced by the translation table on which map_char_table is
 225    operated.  */
 226
 227 static void
 228 shuffle (table, c, elt)
 229      Lisp_Object table, c, elt;
 230 {
 231   if (NATNUMP (elt))
 232     {
 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         {
 245           Lisp_Object tem = Faref (table, elt);
 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_c_string ("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_c_string ("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_c_string ("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) */