1*36ac495dSmrg /* Plural expression evaluation.
2*36ac495dSmrg Copyright (C) 2000-2002 Free Software Foundation, Inc.
3*36ac495dSmrg
4*36ac495dSmrg This program is free software; you can redistribute it and/or modify it
5*36ac495dSmrg under the terms of the GNU Library General Public License as published
6*36ac495dSmrg by the Free Software Foundation; either version 2, or (at your option)
7*36ac495dSmrg any later version.
8*36ac495dSmrg
9*36ac495dSmrg This program is distributed in the hope that it will be useful,
10*36ac495dSmrg but WITHOUT ANY WARRANTY; without even the implied warranty of
11*36ac495dSmrg MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12*36ac495dSmrg Library General Public License for more details.
13*36ac495dSmrg
14*36ac495dSmrg You should have received a copy of the GNU Library General Public
15*36ac495dSmrg License along with this program; if not, write to the Free Software
16*36ac495dSmrg Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301,
17*36ac495dSmrg USA. */
18*36ac495dSmrg
19*36ac495dSmrg #ifndef STATIC
20*36ac495dSmrg #define STATIC static
21*36ac495dSmrg #endif
22*36ac495dSmrg
23*36ac495dSmrg /* Evaluate the plural expression and return an index value. */
24*36ac495dSmrg STATIC unsigned long int plural_eval PARAMS ((struct expression *pexp,
25*36ac495dSmrg unsigned long int n))
26*36ac495dSmrg internal_function;
27*36ac495dSmrg
28*36ac495dSmrg STATIC
29*36ac495dSmrg unsigned long int
30*36ac495dSmrg internal_function
plural_eval(pexp,n)31*36ac495dSmrg plural_eval (pexp, n)
32*36ac495dSmrg struct expression *pexp;
33*36ac495dSmrg unsigned long int n;
34*36ac495dSmrg {
35*36ac495dSmrg switch (pexp->nargs)
36*36ac495dSmrg {
37*36ac495dSmrg case 0:
38*36ac495dSmrg switch (pexp->operation)
39*36ac495dSmrg {
40*36ac495dSmrg case var:
41*36ac495dSmrg return n;
42*36ac495dSmrg case num:
43*36ac495dSmrg return pexp->val.num;
44*36ac495dSmrg default:
45*36ac495dSmrg break;
46*36ac495dSmrg }
47*36ac495dSmrg /* NOTREACHED */
48*36ac495dSmrg break;
49*36ac495dSmrg case 1:
50*36ac495dSmrg {
51*36ac495dSmrg /* pexp->operation must be lnot. */
52*36ac495dSmrg unsigned long int arg = plural_eval (pexp->val.args[0], n);
53*36ac495dSmrg return ! arg;
54*36ac495dSmrg }
55*36ac495dSmrg case 2:
56*36ac495dSmrg {
57*36ac495dSmrg unsigned long int leftarg = plural_eval (pexp->val.args[0], n);
58*36ac495dSmrg if (pexp->operation == lor)
59*36ac495dSmrg return leftarg || plural_eval (pexp->val.args[1], n);
60*36ac495dSmrg else if (pexp->operation == land)
61*36ac495dSmrg return leftarg && plural_eval (pexp->val.args[1], n);
62*36ac495dSmrg else
63*36ac495dSmrg {
64*36ac495dSmrg unsigned long int rightarg = plural_eval (pexp->val.args[1], n);
65*36ac495dSmrg
66*36ac495dSmrg switch (pexp->operation)
67*36ac495dSmrg {
68*36ac495dSmrg case mult:
69*36ac495dSmrg return leftarg * rightarg;
70*36ac495dSmrg case divide:
71*36ac495dSmrg #if !INTDIV0_RAISES_SIGFPE
72*36ac495dSmrg if (rightarg == 0)
73*36ac495dSmrg raise (SIGFPE);
74*36ac495dSmrg #endif
75*36ac495dSmrg return leftarg / rightarg;
76*36ac495dSmrg case module:
77*36ac495dSmrg #if !INTDIV0_RAISES_SIGFPE
78*36ac495dSmrg if (rightarg == 0)
79*36ac495dSmrg raise (SIGFPE);
80*36ac495dSmrg #endif
81*36ac495dSmrg return leftarg % rightarg;
82*36ac495dSmrg case plus:
83*36ac495dSmrg return leftarg + rightarg;
84*36ac495dSmrg case minus:
85*36ac495dSmrg return leftarg - rightarg;
86*36ac495dSmrg case less_than:
87*36ac495dSmrg return leftarg < rightarg;
88*36ac495dSmrg case greater_than:
89*36ac495dSmrg return leftarg > rightarg;
90*36ac495dSmrg case less_or_equal:
91*36ac495dSmrg return leftarg <= rightarg;
92*36ac495dSmrg case greater_or_equal:
93*36ac495dSmrg return leftarg >= rightarg;
94*36ac495dSmrg case equal:
95*36ac495dSmrg return leftarg == rightarg;
96*36ac495dSmrg case not_equal:
97*36ac495dSmrg return leftarg != rightarg;
98*36ac495dSmrg default:
99*36ac495dSmrg break;
100*36ac495dSmrg }
101*36ac495dSmrg }
102*36ac495dSmrg /* NOTREACHED */
103*36ac495dSmrg break;
104*36ac495dSmrg }
105*36ac495dSmrg case 3:
106*36ac495dSmrg {
107*36ac495dSmrg /* pexp->operation must be qmop. */
108*36ac495dSmrg unsigned long int boolarg = plural_eval (pexp->val.args[0], n);
109*36ac495dSmrg return plural_eval (pexp->val.args[boolarg ? 1 : 2], n);
110*36ac495dSmrg }
111*36ac495dSmrg }
112*36ac495dSmrg /* NOTREACHED */
113*36ac495dSmrg return 0;
114*36ac495dSmrg }
115