1: /* GNU Emacs routines to deal with case tables.
    2:    Copyright (C) 1993, 1994, 2001, 2002, 2003, 2004,
    3:                  2005, 2006, 2007  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 "charset.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:   CHECK_TYPE (!NILP (Fcase_table_p (obj)), Qcase_table_p, obj);
   71:   return (obj);
   72: }
   73: 
   74: DEFUN ("current-case-table", Fcurrent_case_table, Scurrent_case_table, 0, 0, 0,
   75:        doc: /* Return the case table of the current buffer.  */)
   76:      ()
   77: {
   78:   return current_buffer->downcase_table;
   79: }
   80: 
   81: DEFUN ("standard-case-table", Fstandard_case_table, Sstandard_case_table, 0, 0, 0,
   82:        doc: /* Return the standard case table.
   83: This is the one used for new buffers.  */)
   84:      ()
   85: {
   86:   return Vascii_downcase_table;
   87: }
   88: 
   89: static Lisp_Object set_case_table ();
   90: 
   91: DEFUN ("set-case-table", Fset_case_table, Sset_case_table, 1, 1, 0,
   92:        doc: /* Select a new case table for the current buffer.
   93: A case table is a char-table which maps characters
   94: to their lower-case equivalents.  It also has three \"extra\" slots
   95: which may be additional char-tables or nil.
   96: These slots are called UPCASE, CANONICALIZE and EQUIVALENCES.
   97: UPCASE maps each non-upper-case character to its upper-case equivalent.
   98:  (The value in UPCASE for an upper-case character is never used.)
   99:  If lower and upper case characters are in 1-1 correspondence,
  100:  you may use nil and the upcase table will be deduced from DOWNCASE.
  101: CANONICALIZE maps each character to a canonical equivalent;
  102:  any two characters that are related by case-conversion have the same
  103:  canonical equivalent character; it may be nil, in which case it is
  104:  deduced from DOWNCASE and UPCASE.
  105: EQUIVALENCES is a map that cyclicly permutes each equivalence class
  106:  (of characters with the same canonical equivalent); it may be nil,
  107:  in which case it is deduced from CANONICALIZE.  */)
  108:      (table)
  109:      Lisp_Object table;
  110: {
  111:   return set_case_table (table, 0);
  112: }
  113: 
  114: DEFUN ("set-standard-case-table", Fset_standard_case_table, Sset_standard_case_table, 1, 1, 0,
  115:        doc: /* Select a new standard case table for new buffers.
  116: See `set-case-table' for more info on case tables.  */)
  117:      (table)
  118:      Lisp_Object table;
  119: {
  120:   return set_case_table (table, 1);
  121: }
  122: 
  123: static Lisp_Object
  124: set_case_table (table, standard)
  125:      Lisp_Object table;
  126:      int standard;
  127: {
  128:   Lisp_Object up, canon, eqv;
  129:   Lisp_Object indices[3];
  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, table, up, 0, indices);
  141:       map_char_table (shuffle, Qnil, table, table, up, 0, indices);
  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, table, 0, indices);
  150:     }
  151: 
  152:   if (NILP (eqv))
  153:     {
  154:       eqv = Fmake_char_table (Qcase_table, Qnil);
  155:       map_char_table (set_identity, Qnil, canon, canon, eqv, 0, indices);
  156:       map_char_table (shuffle, Qnil, canon, canon, eqv, 0, indices);
  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: ^L
  181: /* The following functions are called in map_char_table.  */
  182: 
  183: /*  Set CANON char-table element for C to a translated ELT by UP and
  184:    DOWN char-tables.  This is done only when ELT is a character.  The
  185:    char-tables CANON, UP, and DOWN are in CASE_TABLE.  */
  186: 
  187: static void
  188: set_canon (case_table, c, elt)
  189:      Lisp_Object case_table, c, elt;
  190: {
  191:   Lisp_Object up = XCHAR_TABLE (case_table)->extras[0];
  192:   Lisp_Object canon = XCHAR_TABLE (case_table)->extras[1];
  193: 
  194:   if (NATNUMP (elt))
  195:     Faset (canon, c, Faref (case_table, Faref (up, elt)));
  196: }
  197: 
  198: /* Set elements of char-table TABLE for C to C itself.  This is done
  199:    only when ELT is a 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:     Faset (table, c, c);
  207: }
  208: 
  209: /* Permute the elements of TABLE (which is initially an identity
  210:    mapping) so that it has one cycle for each equivalence class
  211:    induced by the translation table on which map_char_table is
  212:    operated.  */
  213: 
  214: static void
  215: shuffle (table, c, elt)
  216:      Lisp_Object table, c, elt;
  217: {
  218:   if (NATNUMP (elt) && !EQ (c, elt))
  219:     {
  220:       Lisp_Object tem = Faref (table, elt);
  221:       Faset (table, elt, c);
  222:       Faset (table, c, tem);
  223:     }
  224: }
  225: ^L
  226: void
  227: init_casetab_once ()
  228: {
  229:   register int i;
  230:   Lisp_Object down, up;
  231:   Qcase_table = intern ("case-table");
  232:   staticpro (&Qcase_table);
  233: 
  234:   /* Intern this now in case it isn't already done.
  235:      Setting this variable twice is harmless.
  236:      But don't staticpro it here--that is done in alloc.c.  */
  237:   Qchar_table_extra_slots = intern ("char-table-extra-slots");
  238: 
  239:   /* Now we are ready to set up this property, so we can
  240:      create char tables.  */
  241:   Fput (Qcase_table, Qchar_table_extra_slots, make_number (3));
  242: 
  243:   down = Fmake_char_table (Qcase_table, Qnil);
  244:   Vascii_downcase_table = down;
  245:   XCHAR_TABLE (down)->purpose = Qcase_table;
  246: 
  247:   for (i = 0; i < CHAR_TABLE_SINGLE_BYTE_SLOTS; i++)
  248:     XSETFASTINT (XCHAR_TABLE (down)->contents[i],
  249:                  (i >= 'A' && i <= 'Z') ? i + ('a' - 'A') : i);
  250: 
  251:   XCHAR_TABLE (down)->extras[1] = Fcopy_sequence (down);
  252: 
  253:   up = Fmake_char_table (Qcase_table, Qnil);
  254:   XCHAR_TABLE (down)->extras[0] = up;
  255: 
  256:   for (i = 0; i < CHAR_TABLE_SINGLE_BYTE_SLOTS; i++)
  257:     XSETFASTINT (XCHAR_TABLE (up)->contents[i],
  258:                  ((i >= 'A' && i <= 'Z')
  259:                   ? i + ('a' - 'A')
  260:                   : ((i >= 'a' && i <= 'z')
  261:                      ? i + ('A' - 'a')
  262:                      : i)));
  263: 
  264:   XCHAR_TABLE (down)->extras[2] = Fcopy_sequence (up);
  265: 
  266:   /* Fill in what isn't filled in.  */
  267:   set_case_table (down, 1);
  268: }
  269: 
  270: void
  271: syms_of_casetab ()
  272: {
  273:   Qcase_table_p = intern ("case-table-p");
  274:   staticpro (&Qcase_table_p);
  275: 
  276:   staticpro (&Vascii_canon_table);
  277:   staticpro (&Vascii_downcase_table);
  278:   staticpro (&Vascii_eqv_table);
  279:   staticpro (&Vascii_upcase_table);
  280: 
  281:   defsubr (&Scase_table_p);
  282:   defsubr (&Scurrent_case_table);
  283:   defsubr (&Sstandard_case_table);
  284:   defsubr (&Sset_case_table);
  285:   defsubr (&Sset_standard_case_table);
  286: }
  287: 
  288: /* arch-tag: e06388ad-99fe-40ec-ba67-9d010fcc4916
  289:    (do not change this comment) */