locale/indigitswc.h

   1 /* Copyright (C) 2000-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.org>, 2000.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <assert.h>
  20 #include <langinfo.h>
  21
  22 /* Look up the value of the next multibyte character and return its numerical
  23    value if it is one of the digits known in the locale.  If *DECIDED is
  24    -1 this means it is not yet decided which form it is and we have to
  25    search through all available digits.  Otherwise we know which script
  26    the digits are from.  */
  27 static inline int
  28 indigitwc_value (wchar_t wc, int *decided)
  29 {
  30   int from_level;
  31   int to_level;
  32   const wchar_t *wcdigits[10];
  33   int n;
  34
  35   if (*decided != -1)
  36     from_level = to_level = *decided;
  37   else
  38     {
  39       from_level = 0;
  40       to_level = _NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_INDIGITS_WC_LEN) - 1;
  41       assert (from_level <= to_level);
  42     }
  43
  44   /* In this round we get the pointer to the digit strings and also perform
  45      the first round of comparisons.  */
  46   for (n = 0; n < 10; ++n)
  47     {
  48       /* Get the string for the digits with value N.  */
  49       wcdigits[n] = _NL_CURRENT (LC_CTYPE, _NL_CTYPE_INDIGITS0_WC + n);
  50       wcdigits[n] += from_level;
  51
  52       if (wc == *wcdigits[n])
  53         {
  54           /* Found it.  */
  55           if (*decided == -1)
  56             *decided = 0;
  57           return n;
  58         }
  59
  60       /* Advance the pointer to the next string.  */
  61       ++wcdigits[n];
  62     }
  63
  64   /* Now perform the remaining tests.  */
  65   while (++from_level <= to_level)
  66     {
  67       /* Search all ten digits of this level.  */
  68       for (n = 0; n < 10; ++n)
  69         {
  70           if (wc == *wcdigits[n])
  71             {
  72               /* Found it.  */
  73               if (*decided == -1)
  74                 *decided = from_level;
  75               return n;
  76             }
  77
  78           /* Advance the pointer to the next string.  */
  79           ++wcdigits[n];
  80         }
  81     }
  82
  83   /* If we reach this point no matching digit was found.  */
  84   return -1;
  85 }