my %dispatch = (
    SCALAR => sub{ return 1; },
    ARRAY  => sub {
        my $ref = shift;

        my $n = scalar(@$ref);
        for(my $i = 0; $i < $n; ++$i)
        {
            my $result = clean($ref->[ $i ]);
            if($result == 0)
            {
                splice(@$ref, $i, 1);
                $i--;
                $n--;
            }
         }

        unless(@$ref)
        {
            return 0;
        }
    },
    "HASH"  => sub {
            my $ref = shift;

            while(my ($key, $value) = each( %$ref))
            {
                  my $result = clean($value);

                  if ($result == 0) {
                        delete($ref->{$key});
                  }
            }

            my $n = scalar(keys %$ref);
            if ($n == 0) {
                  return 0;
            }
            return 1;
    },
    REF  => sub{ my $ref = shift; die "REF: $ref not allowed"; },
    CODE => sub{ my $ref = shift; die "CODE: $ref not allowed"; },
    ''  => sub{ return 1; },
);