Logo Search packages:      
Sourcecode: libgphoto2 version File versions  Download package

eval-plural.h

/* Plural expression evaluation.
   Copyright (C) 2000-2003 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU Library General Public License as published
   by the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
   USA.  */

#ifndef STATIC
#define STATIC static
#endif

/* Evaluate the plural expression and return an index value.  */
STATIC
unsigned long int
internal_function
plural_eval (struct expression *pexp, unsigned long int n)
{
  switch (pexp->nargs)
    {
    case 0:
      switch (pexp->operation)
      {
      case var:
        return n;
      case num:
        return pexp->val.num;
      default:
        break;
      }
      /* NOTREACHED */
      break;
    case 1:
      {
      /* pexp->operation must be lnot.  */
      unsigned long int arg = plural_eval (pexp->val.args[0], n);
      return ! arg;
      }
    case 2:
      {
      unsigned long int leftarg = plural_eval (pexp->val.args[0], n);
      if (pexp->operation == lor)
        return leftarg || plural_eval (pexp->val.args[1], n);
      else if (pexp->operation == land)
        return leftarg && plural_eval (pexp->val.args[1], n);
      else
        {
          unsigned long int rightarg = plural_eval (pexp->val.args[1], n);

          switch (pexp->operation)
            {
            case mult:
            return leftarg * rightarg;
            case divide:
#if !INTDIV0_RAISES_SIGFPE
            if (rightarg == 0)
              raise (SIGFPE);
#endif
            return leftarg / rightarg;
            case module:
#if !INTDIV0_RAISES_SIGFPE
            if (rightarg == 0)
              raise (SIGFPE);
#endif
            return leftarg % rightarg;
            case plus:
            return leftarg + rightarg;
            case minus:
            return leftarg - rightarg;
            case less_than:
            return leftarg < rightarg;
            case greater_than:
            return leftarg > rightarg;
            case less_or_equal:
            return leftarg <= rightarg;
            case greater_or_equal:
            return leftarg >= rightarg;
            case equal:
            return leftarg == rightarg;
            case not_equal:
            return leftarg != rightarg;
            default:
            break;
            }
        }
      /* NOTREACHED */
      break;
      }
    case 3:
      {
      /* pexp->operation must be qmop.  */
      unsigned long int boolarg = plural_eval (pexp->val.args[0], n);
      return plural_eval (pexp->val.args[boolarg ? 1 : 2], n);
      }
    }
  /* NOTREACHED */
  return 0;
}

Generated by  Doxygen 1.6.0   Back to index