# $list = list_reverse( $list )
#   Reverse the order of the elements of a list.
sub list_reverse {
    my $old = shift;
    my $new = undef;

    while (my $cur = $old) {
        $old = $old->[NEXT];
        $cur->[NEXT] = $new;
        $new = $cur;
    }

    return $new;
}