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

   1 /* GNU Emacs routines to deal with case tables.
   2    Copyright (C) 1993, 1994, 2002, 2003, 2004,
   3                  2005, 2006 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 non-upper-case character to its upper-case equivalent.
 101  (The value in UPCASE for an upper-case character is never used.)
 102  If lower and upper case characters are in 1-1 correspondence,
 103  you may use nil and the upcase table will be deduced from DOWNCASE.
 104 CANONICALIZE maps each character to a canonical equivalent;
 105  any two characters that are related by case-conversion have the same
 106  canonical equivalent character; it may be nil, in which case it is
 107  deduced from DOWNCASE and UPCASE.
 108 EQUIVALENCES is a map that cyclicly permutes each equivalence class
 109  (of characters with the same canonical equivalent); it may be nil,
 110  in which case it is deduced from CANONICALIZE.  */)
 111      (table)
 112      Lisp_Object table;
 113 {
 114   return set_case_table (table, 0);
 115 }
 116
 117 DEFUN ("set-standard-case-table", Fset_standard_case_table, Sset_standard_case_table, 1, 1, 0,
 118        doc: /* Select a new standard case table for new buffers.
 119 See `set-case-table' for more info on case tables.  */)
 120      (table)
 121      Lisp_Object table;
 122 {
 123   return set_case_table (table, 1);
 124 }
 125
 126 static Lisp_Object
 127 set_case_table (table, standard)
 128      Lisp_Object table;
 129      int standard;
 130 {
 131   Lisp_Object up, canon, eqv;
 132
 133   check_case_table (table);
 134
 135   up = XCHAR_TABLE (table)->extras[0];
 136   canon = XCHAR_TABLE (table)->extras[1];
 137   eqv = XCHAR_TABLE (table)->extras[2];
 138
 139   if (NILP (up))
 140     {
 141       up = Fmake_char_table (Qcase_table, Qnil);
 142       map_char_table (set_identity, Qnil, table, up);
 143       map_char_table (shuffle, Qnil, table, up);
 144       XCHAR_TABLE (table)->extras[0] = up;
 145     }
 146
 147   if (NILP (canon))
 148     {
 149       canon = Fmake_char_table (Qcase_table, Qnil);
 150       XCHAR_TABLE (table)->extras[1] = canon;
 151       map_char_table (set_canon, Qnil, table, table);
 152     }
 153
 154   if (NILP (eqv))
 155     {
 156       eqv = Fmake_char_table (Qcase_table, Qnil);
 157       map_char_table (set_identity, Qnil, canon, eqv);
 158       map_char_table (shuffle, Qnil, canon, eqv);
 159       XCHAR_TABLE (table)->extras[2] = eqv;
 160     }
 161
 162   /* This is so set_image_of_range_1 in regex.c can find the EQV table.  */
 163   XCHAR_TABLE (canon)->extras[2] = eqv;
 164
 165   if (standard)
 166     {
 167       Vascii_downcase_table = table;
 168       Vascii_upcase_table = up;
 169       Vascii_canon_table = canon;
 170       Vascii_eqv_table = eqv;
 171     }
 172   else
 173     {
 174       current_buffer->downcase_table = table;
 175       current_buffer->upcase_table = up;
 176       current_buffer->case_canon_table = canon;
 177       current_buffer->case_eqv_table = eqv;
 178     }
 179
 180   return table;
 181 }
 182 \f
 183 /* The following functions are called in map_char_table.  */
 184
 185 /* Set CANON char-table element for characters in RANGE to a
 186    translated ELT by UP and DOWN char-tables.  This is done only when
 187    ELT is a character.  The char-tables CANON, UP, and DOWN are in
 188    CASE_TABLE.  */
 189
 190 static void
 191 set_canon (case_table, range, elt)
 192      Lisp_Object case_table, range, elt;
 193 {
 194   Lisp_Object up = XCHAR_TABLE (case_table)->extras[0];
 195   Lisp_Object canon = XCHAR_TABLE (case_table)->extras[1];
 196
 197   if (NATNUMP (elt))
 198     Fset_char_table_range (canon, range, Faref (case_table, Faref (up, elt)));
 199 }
 200
 201 /* Set elements of char-table TABLE for C to C itself.  C may be a
 202    cons specifying a character range.  In that case, set characters in
 203    that range to themselves.  This is done only when ELT is a
 204    character.  This is called in map_char_table.  */
 205
 206 static void
 207 set_identity (table, c, elt)
 208      Lisp_Object table, c, elt;
 209 {
 210   if (NATNUMP (elt))
 211     {
 212       int from, to;
 213
 214       if (CONSP (c))
 215         {
 216           from = XINT (XCAR (c));
 217           to = XINT (XCDR (c));
 218         }
 219       else
 220         from = to = XINT (c);
 221       for (; from <= to; from++)
 222         CHAR_TABLE_SET (table, from, make_number (from));
 223     }
 224 }
 225
 226 /* Permute the elements of TABLE (which is initially an identity
 227    mapping) so that it has one cycle for each equivalence class
 228    induced by the translation table on which map_char_table is
 229    operated.  */
 230
 231 static void
 232 shuffle (table, c, elt)
 233      Lisp_Object table, c, elt;
 234 {
 235   if (NATNUMP (elt))
 236     {
 237       Lisp_Object tem = Faref (table, elt);
 238       int from, to;
 239
 240       if (CONSP (c))
 241         {
 242           from = XINT (XCAR (c));
 243           to = XINT (XCDR (c));
 244         }
 245       else
 246         from = to = XINT (c);
 247
 248       for (; from <= to; from++)
 249         if (from != XINT (elt))
 250           {
 251             Faset (table, elt, make_number (from));
 252             Faset (table, make_number (from), tem);
 253           }
 254     }
 255 }
 256 \f
 257 void
 258 init_casetab_once ()
 259 {
 260   register int i;
 261   Lisp_Object down, up;
 262   Qcase_table = intern ("case-table");
 263   staticpro (&Qcase_table);
 264
 265   /* Intern this now in case it isn't already done.
 266      Setting this variable twice is harmless.
 267      But don't staticpro it here--that is done in alloc.c.  */
 268   Qchar_table_extra_slots = intern ("char-table-extra-slots");
 269
 270   /* Now we are ready to set up this property, so we can
 271      create char tables.  */
 272   Fput (Qcase_table, Qchar_table_extra_slots, make_number (3));
 273
 274   down = Fmake_char_table (Qcase_table, Qnil);
 275   Vascii_downcase_table = down;
 276   XCHAR_TABLE (down)->purpose = Qcase_table;
 277
 278   for (i = 0; i < 128; i++)
 279     {
 280       int c = (i >= 'A' && i <= 'Z') ? i + ('a' - 'A') : i;
 281       CHAR_TABLE_SET (down, i, make_number (c));
 282     }
 283
 284   XCHAR_TABLE (down)->extras[1] = Fcopy_sequence (down);
 285
 286   up = Fmake_char_table (Qcase_table, Qnil);
 287   XCHAR_TABLE (down)->extras[0] = up;
 288
 289   for (i = 0; i < 128; i++)
 290     {
 291       int c = ((i >= 'A' && i <= 'Z') ? i + ('a' - 'A')
 292                : ((i >= 'a' && i <= 'z') ? i + ('A' - 'a')
 293                   : i));;
 294       CHAR_TABLE_SET (up, i, make_number (c));
 295     }
 296
 297   XCHAR_TABLE (down)->extras[2] = Fcopy_sequence (up);
 298 }
 299
 300 void
 301 syms_of_casetab ()
 302 {
 303   Qcase_table_p = intern ("case-table-p");
 304   staticpro (&Qcase_table_p);
 305
 306   staticpro (&Vascii_canon_table);
 307   staticpro (&Vascii_downcase_table);
 308   staticpro (&Vascii_eqv_table);
 309   staticpro (&Vascii_upcase_table);
 310
 311   defsubr (&Scase_table_p);
 312   defsubr (&Scurrent_case_table);
 313   defsubr (&Sstandard_case_table);
 314   defsubr (&Sset_case_table);
 315   defsubr (&Sset_standard_case_table);
 316 }
 317
 318 /* arch-tag: e06388ad-99fe-40ec-ba67-9d010fcc4916
 319    (do not change this comment) */