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bf070c84 SE |
1 | /* Plural expression evaluation. |
2 | Copyright (C) 2000-2002 Free Software Foundation, Inc. | |
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., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, | |
17 | USA. */ | |
18 | ||
19 | #ifndef STATIC | |
20 | #define STATIC static | |
21 | #endif | |
22 | ||
23 | /* Evaluate the plural expression and return an index value. */ | |
24 | STATIC unsigned long int plural_eval PARAMS ((struct expression *pexp, | |
25 | unsigned long int n)) | |
26 | internal_function; | |
27 | ||
28 | STATIC | |
29 | unsigned long int | |
30 | internal_function | |
31 | plural_eval (pexp, n) | |
32 | struct expression *pexp; | |
33 | unsigned long int n; | |
34 | { | |
35 | switch (pexp->nargs) | |
36 | { | |
37 | case 0: | |
38 | switch (pexp->operation) | |
39 | { | |
40 | case var: | |
41 | return n; | |
42 | case num: | |
43 | return pexp->val.num; | |
44 | default: | |
45 | break; | |
46 | } | |
47 | /* NOTREACHED */ | |
48 | break; | |
49 | case 1: | |
50 | { | |
51 | /* pexp->operation must be lnot. */ | |
52 | unsigned long int arg = plural_eval (pexp->val.args[0], n); | |
53 | return ! arg; | |
54 | } | |
55 | case 2: | |
56 | { | |
57 | unsigned long int leftarg = plural_eval (pexp->val.args[0], n); | |
58 | if (pexp->operation == lor) | |
59 | return leftarg || plural_eval (pexp->val.args[1], n); | |
60 | else if (pexp->operation == land) | |
61 | return leftarg && plural_eval (pexp->val.args[1], n); | |
62 | else | |
63 | { | |
64 | unsigned long int rightarg = plural_eval (pexp->val.args[1], n); | |
65 | ||
66 | switch (pexp->operation) | |
67 | { | |
68 | case mult: | |
69 | return leftarg * rightarg; | |
70 | case divide: | |
71 | #if !INTDIV0_RAISES_SIGFPE | |
72 | if (rightarg == 0) | |
73 | raise (SIGFPE); | |
74 | #endif | |
75 | return leftarg / rightarg; | |
76 | case module: | |
77 | #if !INTDIV0_RAISES_SIGFPE | |
78 | if (rightarg == 0) | |
79 | raise (SIGFPE); | |
80 | #endif | |
81 | return leftarg % rightarg; | |
82 | case plus: | |
83 | return leftarg + rightarg; | |
84 | case minus: | |
85 | return leftarg - rightarg; | |
86 | case less_than: | |
87 | return leftarg < rightarg; | |
88 | case greater_than: | |
89 | return leftarg > rightarg; | |
90 | case less_or_equal: | |
91 | return leftarg <= rightarg; | |
92 | case greater_or_equal: | |
93 | return leftarg >= rightarg; | |
94 | case equal: | |
95 | return leftarg == rightarg; | |
96 | case not_equal: | |
97 | return leftarg != rightarg; | |
98 | default: | |
99 | break; | |
100 | } | |
101 | } | |
102 | /* NOTREACHED */ | |
103 | break; | |
104 | } | |
105 | case 3: | |
106 | { | |
107 | /* pexp->operation must be qmop. */ | |
108 | unsigned long int boolarg = plural_eval (pexp->val.args[0], n); | |
109 | return plural_eval (pexp->val.args[boolarg ? 1 : 2], n); | |
110 | } | |
111 | } | |
112 | /* NOTREACHED */ | |
113 | return 0; | |
114 | } |