sub evaluate
{
    my $contvar = shift;
    shift;
    my $estr = join(' ', @_);
    my @whatsleft = @_;
    print " evaluating '$estr'\n";
    $estr =~ s/ARRAY\x28[^\x28\x29]+\x29//g;
    $estr = trim($estr);
    if ($estr !~ /^[\s\.\/\x28\x290-9eE*+-]+$/)
    {
	my $parser = SpiceGrammar->new()
	    or die "Bad SpiceGrammar: $!\n";
	print "  evaluating variable\n";
	defined(my $value = $parser->vardef($estr))
	    or die "Bad input: {$estr} $!\n";
	if ($value eq '') { $value = 0; print " substituting\n"; }
	return $value;
    }
    else
    {
	my $value = eval($estr);
	$vartable{$contvar} = $value;
	return $value;
    }
}