void forloop(char *var, double from, double to, int op,
double by, char *str) /* set up a for loop */
{
dprintf("# for %s from %g to %g by %c %g \n",
var, from, to, op, by);
if (++forp >= forstk+10)
ERROR "for loop nested too deep" FATAL;
forp->var = var;
forp->to = to;
forp->op = op;
forp->by = by;
forp->str = str;
setfval(var, from);
nextfor();
unput('\n');
}
void
forloop(char *var, double from, double to, int op, double by, char *str)
{
if (++forp >= forstk+10)
fatal("for loop nested too deep");
/* note: actually we here want to take a vector variable and construct its */
/* values directly, then access them one at a time below; the current */
/* version is a temporary concession to old pic's version of the 'for' */
forp->sym = findvar(var, VARNAME);
if (forp->sym->s_dim && forp->sym->s_val.a)
free(forp->sym->s_val.a);
forp->sym->s_dim = 0;
forp->sym->s_val.f = from;
forp->to = to;
if (by == 0.)
fatal("step size of 0 not allowed");
/* For additive or subtractive step, make sure step is positive.
Otherwise, make sure step is greater than 1 in absolute value. */
if ((op == ' ' || op == '+') && by < 0.) {
op = '-';
by = -by;
}
else if (op == '-' && by < 0.) {
op = '+';
by = -by;
}
else if (op == '*' && fabs(by) < 1.) {
op = '/';
by = 1 / by;
}
else if (op == '/' && fabs(by) < 1.) {
op = '*';
by = 1 / by;
}
forp->op = op;
forp->by = by;
forp->str = str;
nextfor();
unput('\n');
}
void
endfor(void) /* end one iteration of for loop */
{
switch (forp->op) {
case '+':
case ' ':
forp->sym->s_val.f += forp->by;
break;
case '-':
forp->sym->s_val.f -= forp->by;
break;
case '*':
forp->sym->s_val.f *= forp->by;
break;
case '/':
forp->sym->s_val.f /= forp->by;
break;
}
nextfor();
}
void endfor(void) /* end one iteration of for loop */
{
struct symtab *p = lookup(forp->var);
switch (forp->op) {
case '+':
case ' ':
p->s_val.f += forp->by;
break;
case '-':
p->s_val.f -= forp->by;
break;
case '*':
p->s_val.f *= forp->by;
break;
case '/':
p->s_val.f /= forp->by;
break;
}
nextfor();
}
