vorbis-tools-1.2.0/intl/eval-plural.h

   1 /* Plural expression evaluation.
   2    Copyright (C) 2000-2003 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify it
   5    under the terms of the GNU Library General Public License as published
   6    by the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with this program; if not, write to the Free Software
  16    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  17    USA.  */
  18
  19 #ifndef STATIC
  20 #define STATIC static
  21 #endif
  22
  23 /* Evaluate the plural expression and return an index value.  */
  24 STATIC
  25 unsigned long int
  26 internal_function
  27 plural_eval (struct expression *pexp, unsigned long int n)
  28 {
  29   switch (pexp->nargs)
  30     {
  31     case 0:
  32       switch (pexp->operation)
  33         {
  34         case var:
  35           return n;
  36         case num:
  37           return pexp->val.num;
  38         default:
  39           break;
  40         }
  41       /* NOTREACHED */
  42       break;
  43     case 1:
  44       {
  45         /* pexp->operation must be lnot.  */
  46         unsigned long int arg = plural_eval (pexp->val.args[0], n);
  47         return ! arg;
  48       }
  49     case 2:
  50       {
  51         unsigned long int leftarg = plural_eval (pexp->val.args[0], n);
  52         if (pexp->operation == lor)
  53           return leftarg || plural_eval (pexp->val.args[1], n);
  54         else if (pexp->operation == land)
  55           return leftarg && plural_eval (pexp->val.args[1], n);
  56         else
  57           {
  58             unsigned long int rightarg = plural_eval (pexp->val.args[1], n);
  59
  60             switch (pexp->operation)
  61               {
  62               case mult:
  63                 return leftarg * rightarg;
  64               case divide:
  65 #if !INTDIV0_RAISES_SIGFPE
  66                 if (rightarg == 0)
  67                   raise (SIGFPE);
  68 #endif
  69                 return leftarg / rightarg;
  70               case module:
  71 #if !INTDIV0_RAISES_SIGFPE
  72                 if (rightarg == 0)
  73                   raise (SIGFPE);
  74 #endif
  75                 return leftarg % rightarg;
  76               case plus:
  77                 return leftarg + rightarg;
  78               case minus:
  79                 return leftarg - rightarg;
  80               case less_than:
  81                 return leftarg < rightarg;
  82               case greater_than:
  83                 return leftarg > rightarg;
  84               case less_or_equal:
  85                 return leftarg <= rightarg;
  86               case greater_or_equal:
  87                 return leftarg >= rightarg;
  88               case equal:
  89                 return leftarg == rightarg;
  90               case not_equal:
  91                 return leftarg != rightarg;
  92               default:
  93                 break;
  94               }
  95           }
  96         /* NOTREACHED */
  97         break;
  98       }
  99     case 3:
 100       {
 101         /* pexp->operation must be qmop.  */
 102         unsigned long int boolarg = plural_eval (pexp->val.args[0], n);
 103         return plural_eval (pexp->val.args[boolarg ? 1 : 2], n);
 104       }
 105     }
 106   /* NOTREACHED */
 107   return 0;
 108 }