src/oldsed/intl/eval-plural.h

   1 /* Plural expression evaluation.
   2    Copyright (C) 2000, 2001 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 General Public License as published by
   6    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
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  17
  18 #ifndef STATIC
  19 #define STATIC static
  20 #endif
  21
  22 /* Evaluate the plural expression and return an index value.  */
  23 STATIC unsigned long int plural_eval PARAMS ((struct expression *pexp,
  24                                               unsigned long int n))
  25      internal_function;
  26
  27 STATIC
  28 unsigned long int
  29 internal_function
  30 plural_eval (pexp, n)
  31      struct expression *pexp;
  32      unsigned long int n;
  33 {
  34   switch (pexp->nargs)
  35     {
  36     case 0:
  37       switch (pexp->operation)
  38         {
  39         case var:
  40           return n;
  41         case num:
  42           return pexp->val.num;
  43         default:
  44           break;
  45         }
  46       /* NOTREACHED */
  47       break;
  48     case 1:
  49       {
  50         /* pexp->operation must be lnot.  */
  51         unsigned long int arg = plural_eval (pexp->val.args[0], n);
  52         return ! arg;
  53       }
  54     case 2:
  55       {
  56         unsigned long int leftarg = plural_eval (pexp->val.args[0], n);
  57         if (pexp->operation == lor)
  58           return leftarg || plural_eval (pexp->val.args[1], n);
  59         else if (pexp->operation == land)
  60           return leftarg && plural_eval (pexp->val.args[1], n);
  61         else
  62           {
  63             unsigned long int rightarg = plural_eval (pexp->val.args[1], n);
  64
  65             switch (pexp->operation)
  66               {
  67               case mult:
  68                 return leftarg * rightarg;
  69               case divide:
  70                 return leftarg / rightarg;
  71               case module:
  72                 return leftarg % rightarg;
  73               case plus:
  74                 return leftarg + rightarg;
  75               case minus:
  76                 return leftarg - rightarg;
  77               case less_than:
  78                 return leftarg < rightarg;
  79               case greater_than:
  80                 return leftarg > rightarg;
  81               case less_or_equal:
  82                 return leftarg <= rightarg;
  83               case greater_or_equal:
  84                 return leftarg >= rightarg;
  85               case equal:
  86                 return leftarg == rightarg;
  87               case not_equal:
  88                 return leftarg != rightarg;
  89               default:
  90                 break;
  91               }
  92           }
  93         /* NOTREACHED */
  94         break;
  95       }
  96     case 3:
  97       {
  98         /* pexp->operation must be qmop.  */
  99         unsigned long int boolarg = plural_eval (pexp->val.args[0], n);
 100         return plural_eval (pexp->val.args[boolarg ? 1 : 2], n);
 101       }
 102     }
 103   /* NOTREACHED */
 104   return 0;
 105 }