sub enumerate {
    my (%p) = @_;

    my @types = (keys %p);

    my $type = shift(@types);

    my @sub_result;
    if (@types) {
        my %x;
        foreach my $subtype (@types) {
            $x{$subtype} = $p{$subtype};
        }
        (@sub_result) = enumerate(%x);
    }

    my @results;
    foreach my $data (@{$p{$type}}) {
        if (@sub_result) {
            foreach my $result (@sub_result) {
                my %x;
                foreach my $y (keys %$result) {
                    $x{$y} = $result->{$y};
                }
                $x{$type} = $data;
                push(@results, \%x);
            }
        } else {
            push (@results, { $type => $data });
        }
    }
    return (@results);
}


my @sets = enumerate(
    "foo" => [1, 2, 3],
    "bar" => ["A", "B", "C"],
    "biz" => ["Y", "Z"],
);

foreach my $set (@sets) {
    my @out;
    foreach my $key (sort keys %{ $set }) {
        push (@out, "$key => $set->{$key}");
    }
    print join(", ", @out) . "\n";
}
[download]

[bmc@blah bmc]$ perl /tmp/test.pl  |sort
bar => A, biz => Y, foo => 1
bar => A, biz => Y, foo => 2
bar => A, biz => Y, foo => 3
bar => A, biz => Z, foo => 1
bar => A, biz => Z, foo => 2
bar => A, biz => Z, foo => 3
bar => B, biz => Y, foo => 1
bar => B, biz => Y, foo => 2
bar => B, biz => Y, foo => 3
bar => B, biz => Z, foo => 1
bar => B, biz => Z, foo => 2
bar => B, biz => Z, foo => 3
bar => C, biz => Y, foo => 1
bar => C, biz => Y, foo => 2
bar => C, biz => Y, foo => 3
bar => C, biz => Z, foo => 1
bar => C, biz => Z, foo => 2
bar => C, biz => Z, foo => 3
[bmc@blah bmc]$
[download]