| /* Plural expression evaluation. |
| Copyright (C) 2000-2018 Free Software Foundation, Inc. |
| |
| This program is free software: you can redistribute it and/or modify |
| it under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 of the License, 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 Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #ifndef STATIC |
| #define STATIC static |
| #endif |
| |
| /* Evaluate the plural expression and return an index value. */ |
| STATIC |
| unsigned long int |
| plural_eval (const 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; |
| } |