1*4fee23f9Smrg /* Plural expression evaluation.
2*4fee23f9Smrg Copyright (C) 2000-2002 Free Software Foundation, Inc.
3*4fee23f9Smrg
4*4fee23f9Smrg This program is free software; you can redistribute it and/or modify it
5*4fee23f9Smrg under the terms of the GNU Library General Public License as published
6*4fee23f9Smrg by the Free Software Foundation; either version 2, or (at your option)
7*4fee23f9Smrg any later version.
8*4fee23f9Smrg
9*4fee23f9Smrg This program is distributed in the hope that it will be useful,
10*4fee23f9Smrg but WITHOUT ANY WARRANTY; without even the implied warranty of
11*4fee23f9Smrg MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12*4fee23f9Smrg Library General Public License for more details.
13*4fee23f9Smrg
14*4fee23f9Smrg You should have received a copy of the GNU Library General Public
15*4fee23f9Smrg License along with this program; if not, write to the Free Software
16*4fee23f9Smrg Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301,
17*4fee23f9Smrg USA. */
18*4fee23f9Smrg
19*4fee23f9Smrg #ifndef STATIC
20*4fee23f9Smrg #define STATIC static
21*4fee23f9Smrg #endif
22*4fee23f9Smrg
23*4fee23f9Smrg /* Evaluate the plural expression and return an index value. */
24*4fee23f9Smrg STATIC unsigned long int plural_eval PARAMS ((struct expression *pexp,
25*4fee23f9Smrg unsigned long int n))
26*4fee23f9Smrg internal_function;
27*4fee23f9Smrg
28*4fee23f9Smrg STATIC
29*4fee23f9Smrg unsigned long int
30*4fee23f9Smrg internal_function
plural_eval(pexp,n)31*4fee23f9Smrg plural_eval (pexp, n)
32*4fee23f9Smrg struct expression *pexp;
33*4fee23f9Smrg unsigned long int n;
34*4fee23f9Smrg {
35*4fee23f9Smrg switch (pexp->nargs)
36*4fee23f9Smrg {
37*4fee23f9Smrg case 0:
38*4fee23f9Smrg switch (pexp->operation)
39*4fee23f9Smrg {
40*4fee23f9Smrg case var:
41*4fee23f9Smrg return n;
42*4fee23f9Smrg case num:
43*4fee23f9Smrg return pexp->val.num;
44*4fee23f9Smrg default:
45*4fee23f9Smrg break;
46*4fee23f9Smrg }
47*4fee23f9Smrg /* NOTREACHED */
48*4fee23f9Smrg break;
49*4fee23f9Smrg case 1:
50*4fee23f9Smrg {
51*4fee23f9Smrg /* pexp->operation must be lnot. */
52*4fee23f9Smrg unsigned long int arg = plural_eval (pexp->val.args[0], n);
53*4fee23f9Smrg return ! arg;
54*4fee23f9Smrg }
55*4fee23f9Smrg case 2:
56*4fee23f9Smrg {
57*4fee23f9Smrg unsigned long int leftarg = plural_eval (pexp->val.args[0], n);
58*4fee23f9Smrg if (pexp->operation == lor)
59*4fee23f9Smrg return leftarg || plural_eval (pexp->val.args[1], n);
60*4fee23f9Smrg else if (pexp->operation == land)
61*4fee23f9Smrg return leftarg && plural_eval (pexp->val.args[1], n);
62*4fee23f9Smrg else
63*4fee23f9Smrg {
64*4fee23f9Smrg unsigned long int rightarg = plural_eval (pexp->val.args[1], n);
65*4fee23f9Smrg
66*4fee23f9Smrg switch (pexp->operation)
67*4fee23f9Smrg {
68*4fee23f9Smrg case mult:
69*4fee23f9Smrg return leftarg * rightarg;
70*4fee23f9Smrg case divide:
71*4fee23f9Smrg #if !INTDIV0_RAISES_SIGFPE
72*4fee23f9Smrg if (rightarg == 0)
73*4fee23f9Smrg raise (SIGFPE);
74*4fee23f9Smrg #endif
75*4fee23f9Smrg return leftarg / rightarg;
76*4fee23f9Smrg case module:
77*4fee23f9Smrg #if !INTDIV0_RAISES_SIGFPE
78*4fee23f9Smrg if (rightarg == 0)
79*4fee23f9Smrg raise (SIGFPE);
80*4fee23f9Smrg #endif
81*4fee23f9Smrg return leftarg % rightarg;
82*4fee23f9Smrg case plus:
83*4fee23f9Smrg return leftarg + rightarg;
84*4fee23f9Smrg case minus:
85*4fee23f9Smrg return leftarg - rightarg;
86*4fee23f9Smrg case less_than:
87*4fee23f9Smrg return leftarg < rightarg;
88*4fee23f9Smrg case greater_than:
89*4fee23f9Smrg return leftarg > rightarg;
90*4fee23f9Smrg case less_or_equal:
91*4fee23f9Smrg return leftarg <= rightarg;
92*4fee23f9Smrg case greater_or_equal:
93*4fee23f9Smrg return leftarg >= rightarg;
94*4fee23f9Smrg case equal:
95*4fee23f9Smrg return leftarg == rightarg;
96*4fee23f9Smrg case not_equal:
97*4fee23f9Smrg return leftarg != rightarg;
98*4fee23f9Smrg default:
99*4fee23f9Smrg break;
100*4fee23f9Smrg }
101*4fee23f9Smrg }
102*4fee23f9Smrg /* NOTREACHED */
103*4fee23f9Smrg break;
104*4fee23f9Smrg }
105*4fee23f9Smrg case 3:
106*4fee23f9Smrg {
107*4fee23f9Smrg /* pexp->operation must be qmop. */
108*4fee23f9Smrg unsigned long int boolarg = plural_eval (pexp->val.args[0], n);
109*4fee23f9Smrg return plural_eval (pexp->val.args[boolarg ? 1 : 2], n);
110*4fee23f9Smrg }
111*4fee23f9Smrg }
112*4fee23f9Smrg /* NOTREACHED */
113*4fee23f9Smrg return 0;
114*4fee23f9Smrg }
115