intl/eval-plural.h

   1 /* Plural expression evaluation.
   2    Copyright (C) 2000-2016 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU Lesser General Public License as published by
   6    the Free Software Foundation; either version 2.1 of the License, or
   7    (at your option) 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
  12    GNU Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 #ifndef STATIC
  18 #define STATIC static
  19 #endif
  20
  21 /* Evaluate the plural expression and return an index value.  */
  22 STATIC
  23 unsigned long int
  24 internal_function
  25 plural_eval (const struct expression *pexp, unsigned long int n)
  26 {
  27   switch (pexp->nargs)
  28     {
  29     case 0:
  30       switch (pexp->operation)
  31         {
  32         case var:
  33           return n;
  34         case num:
  35           return pexp->val.num;
  36         default:
  37           break;
  38         }
  39       /* NOTREACHED */
  40       break;
  41     case 1:
  42       {
  43         /* pexp->operation must be lnot.  */
  44         unsigned long int arg = plural_eval (pexp->val.args[0], n);
  45         return ! arg;
  46       }
  47     case 2:
  48       {
  49         unsigned long int leftarg = plural_eval (pexp->val.args[0], n);
  50         if (pexp->operation == lor)
  51           return leftarg || plural_eval (pexp->val.args[1], n);
  52         else if (pexp->operation == land)
  53           return leftarg && plural_eval (pexp->val.args[1], n);
  54         else
  55           {
  56             unsigned long int rightarg = plural_eval (pexp->val.args[1], n);
  57
  58             switch (pexp->operation)
  59               {
  60               case mult:
  61                 return leftarg * rightarg;
  62               case divide:
  63 #if !INTDIV0_RAISES_SIGFPE
  64                 if (rightarg == 0)
  65                   raise (SIGFPE);
  66 #endif
  67                 return leftarg / rightarg;
  68               case module:
  69 #if !INTDIV0_RAISES_SIGFPE
  70                 if (rightarg == 0)
  71                   raise (SIGFPE);
  72 #endif
  73                 return leftarg % rightarg;
  74               case plus:
  75                 return leftarg + rightarg;
  76               case minus:
  77                 return leftarg - rightarg;
  78               case less_than:
  79                 return leftarg < rightarg;
  80               case greater_than:
  81                 return leftarg > rightarg;
  82               case less_or_equal:
  83                 return leftarg <= rightarg;
  84               case greater_or_equal:
  85                 return leftarg >= rightarg;
  86               case equal:
  87                 return leftarg == rightarg;
  88               case not_equal:
  89                 return leftarg != rightarg;
  90               default:
  91                 break;
  92               }
  93           }
  94         /* NOTREACHED */
  95         break;
  96       }
  97     case 3:
  98       {
  99         /* pexp->operation must be qmop.  */
 100         unsigned long int boolarg = plural_eval (pexp->val.args[0], n);
 101         return plural_eval (pexp->val.args[boolarg ? 1 : 2], n);
 102       }
 103     }
 104   /* NOTREACHED */
 105   return 0;
 106 }