libs/unicode/unicode_ultcase.c

   1 /*
   2 ** Copyright 2000-2003 Double Precision, Inc.
   3 ** See COPYING for distribution information.
   4 **
   5 */
   6
   7 #include "unicode_config.h"
   8 #include "unicode.h"
   9
  10 extern const unsigned unicode_case_hash;
  11 extern const unicode_char unicode_case_tab[][4];
  12 extern const unsigned unicode_case_offset[];
  13
  14 static unsigned find_case(unicode_char c)
  15 {
  16         unsigned idx= c % unicode_case_hash;
  17
  18         unsigned i=unicode_case_offset[idx];
  19
  20         unicode_char uc;
  21
  22         --i;
  23
  24         do
  25         {
  26                 uc=unicode_case_tab[++i][0];
  27                 if (uc == c)
  28                         return (i);
  29         } while ( (uc % unicode_case_hash) == idx);
  30
  31         return (0);
  32 }
  33
  34 unicode_char unicode_uc(unicode_char c)
  35 {
  36         unsigned i=find_case(c);
  37
  38         return (unicode_case_tab[i][0] != c ? c:unicode_case_tab[i][1]);
  39 }
  40
  41 unicode_char unicode_lc(unicode_char c)
  42 {
  43         unsigned i=find_case(c);
  44
  45         return (unicode_case_tab[i][0] != c ? c:unicode_case_tab[i][2]);
  46 }
  47
  48 unicode_char unicode_tc(unicode_char c)
  49 {
  50         unsigned i;
  51         unicode_char oc=c;
  52
  53         c=unicode_lc(c);
  54         i=find_case(c);
  55
  56         return (unicode_case_tab[i][0] != c ? oc:unicode_case_tab[i][3]);
  57 }