Theodore Ts'o | a04eba3 | 2003-05-03 16:35:17 -0400 | [diff] [blame] | 1 | /* Plural expression evaluation. |
Theodore Ts'o | b0cacab | 2004-11-30 19:00:19 -0500 | [diff] [blame] | 2 | Copyright (C) 2000-2003 Free Software Foundation, Inc. |
Theodore Ts'o | a04eba3 | 2003-05-03 16:35:17 -0400 | [diff] [blame] | 3 | |
| 4 | This program is free software; you can redistribute it and/or modify it |
| 5 | under the terms of the GNU Library General Public License as published |
| 6 | by 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 GNU |
| 12 | Library General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Library General Public |
| 15 | License along with this program; if not, write to the Free Software |
| 16 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, |
| 17 | USA. */ |
| 18 | |
| 19 | #ifndef STATIC |
| 20 | #define STATIC static |
| 21 | #endif |
| 22 | |
| 23 | /* Evaluate the plural expression and return an index value. */ |
Theodore Ts'o | a04eba3 | 2003-05-03 16:35:17 -0400 | [diff] [blame] | 24 | STATIC |
| 25 | unsigned long int |
| 26 | internal_function |
Theodore Ts'o | b0cacab | 2004-11-30 19:00:19 -0500 | [diff] [blame] | 27 | plural_eval (struct expression *pexp, unsigned long int n) |
Theodore Ts'o | a04eba3 | 2003-05-03 16:35:17 -0400 | [diff] [blame] | 28 | { |
| 29 | switch (pexp->nargs) |
| 30 | { |
| 31 | case 0: |
| 32 | switch (pexp->operation) |
| 33 | { |
| 34 | case var: |
| 35 | return n; |
| 36 | case num: |
| 37 | return pexp->val.num; |
| 38 | default: |
| 39 | break; |
| 40 | } |
| 41 | /* NOTREACHED */ |
| 42 | break; |
| 43 | case 1: |
| 44 | { |
| 45 | /* pexp->operation must be lnot. */ |
| 46 | unsigned long int arg = plural_eval (pexp->val.args[0], n); |
| 47 | return ! arg; |
| 48 | } |
| 49 | case 2: |
| 50 | { |
| 51 | unsigned long int leftarg = plural_eval (pexp->val.args[0], n); |
| 52 | if (pexp->operation == lor) |
| 53 | return leftarg || plural_eval (pexp->val.args[1], n); |
| 54 | else if (pexp->operation == land) |
| 55 | return leftarg && plural_eval (pexp->val.args[1], n); |
| 56 | else |
| 57 | { |
| 58 | unsigned long int rightarg = plural_eval (pexp->val.args[1], n); |
| 59 | |
| 60 | switch (pexp->operation) |
| 61 | { |
| 62 | case mult: |
| 63 | return leftarg * rightarg; |
| 64 | case divide: |
| 65 | #if !INTDIV0_RAISES_SIGFPE |
| 66 | if (rightarg == 0) |
| 67 | raise (SIGFPE); |
| 68 | #endif |
| 69 | return leftarg / rightarg; |
| 70 | case module: |
| 71 | #if !INTDIV0_RAISES_SIGFPE |
| 72 | if (rightarg == 0) |
| 73 | raise (SIGFPE); |
| 74 | #endif |
| 75 | return leftarg % rightarg; |
| 76 | case plus: |
| 77 | return leftarg + rightarg; |
| 78 | case minus: |
| 79 | return leftarg - rightarg; |
| 80 | case less_than: |
| 81 | return leftarg < rightarg; |
| 82 | case greater_than: |
| 83 | return leftarg > rightarg; |
| 84 | case less_or_equal: |
| 85 | return leftarg <= rightarg; |
| 86 | case greater_or_equal: |
| 87 | return leftarg >= rightarg; |
| 88 | case equal: |
| 89 | return leftarg == rightarg; |
| 90 | case not_equal: |
| 91 | return leftarg != rightarg; |
| 92 | default: |
| 93 | break; |
| 94 | } |
| 95 | } |
| 96 | /* NOTREACHED */ |
| 97 | break; |
| 98 | } |
| 99 | case 3: |
| 100 | { |
| 101 | /* pexp->operation must be qmop. */ |
| 102 | unsigned long int boolarg = plural_eval (pexp->val.args[0], n); |
| 103 | return plural_eval (pexp->val.args[boolarg ? 1 : 2], n); |
| 104 | } |
| 105 | } |
| 106 | /* NOTREACHED */ |
| 107 | return 0; |
| 108 | } |