eval-plural.h
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Visual C++
- /* Plural expression evaluation.
- Copyright (C) 2000-2002 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 plural_eval PARAMS ((struct expression *pexp,
- unsigned long int n))
- internal_function;
- STATIC
- unsigned long int
- internal_function
- plural_eval (pexp, n)
- 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;
- }