1 | /* Plural expression evaluation. |
2 | Copyright (C) 2000-2016 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 Lesser General Public License as published by |
6 | the Free Software Foundation; either version 2.1 of the License, or |
7 | (at your option) 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 Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public License |
15 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
16 | |
17 | #ifndef STATIC |
18 | #define STATIC static |
19 | #endif |
20 | |
21 | /* Evaluate the plural expression and return an index value. */ |
22 | STATIC |
23 | unsigned long int |
24 | internal_function |
25 | plural_eval (const struct expression *pexp, unsigned long int n) |
26 | { |
27 | switch (pexp->nargs) |
28 | { |
29 | case 0: |
30 | switch (pexp->operation) |
31 | { |
32 | case var: |
33 | return n; |
34 | case num: |
35 | return pexp->val.num; |
36 | default: |
37 | break; |
38 | } |
39 | /* NOTREACHED */ |
40 | break; |
41 | case 1: |
42 | { |
43 | /* pexp->operation must be lnot. */ |
44 | unsigned long int arg = plural_eval (pexp->val.args[0], n); |
45 | return ! arg; |
46 | } |
47 | case 2: |
48 | { |
49 | unsigned long int leftarg = plural_eval (pexp->val.args[0], n); |
50 | if (pexp->operation == lor) |
51 | return leftarg || plural_eval (pexp->val.args[1], n); |
52 | else if (pexp->operation == land) |
53 | return leftarg && plural_eval (pexp->val.args[1], n); |
54 | else |
55 | { |
56 | unsigned long int rightarg = plural_eval (pexp->val.args[1], n); |
57 | |
58 | switch (pexp->operation) |
59 | { |
60 | case mult: |
61 | return leftarg * rightarg; |
62 | case divide: |
63 | #if !INTDIV0_RAISES_SIGFPE |
64 | if (rightarg == 0) |
65 | raise (SIGFPE); |
66 | #endif |
67 | return leftarg / rightarg; |
68 | case module: |
69 | #if !INTDIV0_RAISES_SIGFPE |
70 | if (rightarg == 0) |
71 | raise (SIGFPE); |
72 | #endif |
73 | return leftarg % rightarg; |
74 | case plus: |
75 | return leftarg + rightarg; |
76 | case minus: |
77 | return leftarg - rightarg; |
78 | case less_than: |
79 | return leftarg < rightarg; |
80 | case greater_than: |
81 | return leftarg > rightarg; |
82 | case less_or_equal: |
83 | return leftarg <= rightarg; |
84 | case greater_or_equal: |
85 | return leftarg >= rightarg; |
86 | case equal: |
87 | return leftarg == rightarg; |
88 | case not_equal: |
89 | return leftarg != rightarg; |
90 | default: |
91 | break; |
92 | } |
93 | } |
94 | /* NOTREACHED */ |
95 | break; |
96 | } |
97 | case 3: |
98 | { |
99 | /* pexp->operation must be qmop. */ |
100 | unsigned long int boolarg = plural_eval (pexp->val.args[0], n); |
101 | return plural_eval (pexp->val.args[boolarg ? 1 : 2], n); |
102 | } |
103 | } |
104 | /* NOTREACHED */ |
105 | return 0; |
106 | } |
107 | |