static double romberg(double (*fcn)(double), double eps)
{
int j,j1;
double sum,errsum=0,x[16],fx[16];
x[0]=1.0;
for(j=0;j<16;j++){
j1=j+1;
fx[j]=evalfn(fcn,j1);
if(j1>=5){
interp(&x[j1-5],&fx[j1-5],&sum,&errsum);
if(fabs(errsum)<eps*fabs(sum))return(sum);}
x[j1]=x[j]/9.0;
fx[j1]=fx[j];}
sum=R_NaN;
return(sum);}
void
evaltree(union node *n, int flags)
{
int checkexit = 0;
void (*evalfn)(union node *, int);
unsigned isor;
int status;
if (n == NULL) {
//TRACE(("evaltree(NULL) called\n"));
goto out;
}
#ifndef SMALL
displayhist = 1; /* show history substitutions done with fc */
#endif
TRACE(("pid %d, evaltree(%p: %d, %d, %p) called\n",
getpid(), n, n->type, flags));
switch (n->type) {
default:
#ifdef DEBUG
#ifndef USE_GLIBC_STDIO
flushout(out1);
#endif
break;
#endif
case NNOT:
evaltree(n->nnot.com, EV_TESTED);
status = !exitstatus;
goto setstatus;
case NREDIR:
expredir(n->nredir.redirect);
status = redirectsafe(n->nredir.redirect, REDIR_PUSH);
if (!status) {
evaltree(n->nredir.n, flags & EV_TESTED);
status = exitstatus;
}
popredir(0);
goto setstatus;
case NCMD:
#ifdef notyet
if (eflag && !(flags & EV_TESTED))
checkexit = ~0;
evalcommand(n, flags, (struct backcmd *)NULL);
break;
#else
evalfn = evalcommand;
checkexit:
if (eflag && !(flags & EV_TESTED))
checkexit = ~0;
goto calleval;
#endif
case NFOR:
evalfn = evalfor;
goto calleval;
case NWHILE:
case NUNTIL:
evalfn = evalloop;
goto calleval;
case NSUBSHELL:
case NBACKGND:
evalfn = evalsubshell;
evalsubshell (n, flags);
case NPIPE:
evalfn = evalpipe;
#ifdef notyet
if (eflag && !(flags & EV_TESTED))
checkexit = ~0;
goto calleval;
#else
goto checkexit;
#endif
case NCASE:
evalfn = evalcase;
goto calleval;
case NAND:
case NOR:
case NSEMI:
#if NAND + 1 != NOR
#error NAND + 1 != NOR
#endif
#if NOR + 1 != NSEMI
#error NOR + 1 != NSEMI
#endif
isor = n->type - NAND;
evaltree(
n->nbinary.ch1,
(flags | ((isor >> 1) - 1)) & EV_TESTED
);
if (!exitstatus == isor)
break;
if (!evalskip) {
n = n->nbinary.ch2;
evaln:
evaltree(n, flags);
break;
calleval:
evalfn(n, flags);
break;
}
break;
case NIF:
evaltree(n->nif.test, EV_TESTED);
if (evalskip)
break;
if (exitstatus == 0) {
n = n->nif.ifpart;
goto evaln;
} else if (n->nif.elsepart) {
n = n->nif.elsepart;
goto evaln;
}
goto success;
case NDEFUN:
defun(n->narg.text, n->narg.next);
success:
status = 0;
setstatus:
exitstatus = status;
break;
}
out:
if ((checkexit & exitstatus) ||
(pendingsigs && dotrap()) ||
(flags & EV_EXIT))
exraise(EXEXIT);
}
