Greetings,
Nothing novel but this question looked like fun so here are my 2 cents. I will leave the Benchmark tests to those more versed in such things :} 
#!/usr/bin/perl -w

use strict;
use Data::Dumper;

# The HoA below may come in varying
# sizes: from "key1" to "key 50"

my $hash = {
    'key1' => [ 1,   2,   3, 4 ],
    'key2' => [ 10,  20,  30 ],
    'key3' => [ 100, 200, 300 ],
    'key4' => [ 'a','b','c','dood']
};

my (@b, @base);

#compute combos
for(sort keys %{$hash}){
    concat_arrays(\@b, $hash->{$_});
}

#filter computations
@base = grep{ 
        my $count = () =  $_ =~ m/\-/g;
        ($count == (scalar(keys %{$hash})-1)); 
    }sort @base;

#double check
print $_."\n" for(@base);

sub concat_arrays
{
    my ($baseref, $newref) = @_;
    foreach my $new (@{$newref}){
        if(scalar(@{$baseref})){
            foreach my $base (@{$baseref}){
                push @base, $base." - ".$new;
            }
        }else{
            push @base, $new;
        }
    }
    @b = @base;
}

[download]
The output 
1 - 10 - 100 - a
1 - 10 - 100 - b
1 - 10 - 100 - c
1 - 10 - 100 - dood
1 - 10 - 200 - a
1 - 10 - 200 - b
1 - 10 - 200 - c
1 - 10 - 200 - dood
1 - 10 - 300 - a
1 - 10 - 300 - b
1 - 10 - 300 - c
1 - 10 - 300 - dood
1 - 20 - 100 - a
1 - 20 - 100 - b
1 - 20 - 100 - c
1 - 20 - 100 - dood
1 - 20 - 200 - a
1 - 20 - 200 - b
1 - 20 - 200 - c
1 - 20 - 200 - dood
1 - 20 - 300 - a
1 - 20 - 300 - b
1 - 20 - 300 - c
1 - 20 - 300 - dood
1 - 30 - 100 - a
1 - 30 - 100 - b
1 - 30 - 100 - c
1 - 30 - 100 - dood
1 - 30 - 200 - a
1 - 30 - 200 - b
1 - 30 - 200 - c
1 - 30 - 200 - dood
1 - 30 - 300 - a
1 - 30 - 300 - b
1 - 30 - 300 - c
1 - 30 - 300 - dood
2 - 10 - 100 - a
2 - 10 - 100 - b
2 - 10 - 100 - c
2 - 10 - 100 - dood
2 - 10 - 200 - a
2 - 10 - 200 - b
2 - 10 - 200 - c
2 - 10 - 200 - dood
2 - 10 - 300 - a
2 - 10 - 300 - b
2 - 10 - 300 - c
2 - 10 - 300 - dood
2 - 20 - 100 - a
2 - 20 - 100 - b
2 - 20 - 100 - c
2 - 20 - 100 - dood
2 - 20 - 200 - a
2 - 20 - 200 - b
2 - 20 - 200 - c
2 - 20 - 200 - dood
2 - 20 - 300 - a
2 - 20 - 300 - b
2 - 20 - 300 - c
2 - 20 - 300 - dood
2 - 30 - 100 - a
2 - 30 - 100 - b
2 - 30 - 100 - c
2 - 30 - 100 - dood
2 - 30 - 200 - a
2 - 30 - 200 - b
2 - 30 - 200 - c
2 - 30 - 200 - dood
2 - 30 - 300 - a
2 - 30 - 300 - b
2 - 30 - 300 - c
2 - 30 - 300 - dood
3 - 10 - 100 - a
3 - 10 - 100 - b
3 - 10 - 100 - c
3 - 10 - 100 - dood
3 - 10 - 200 - a
3 - 10 - 200 - b
3 - 10 - 200 - c
3 - 10 - 200 - dood
3 - 10 - 300 - a
3 - 10 - 300 - b
3 - 10 - 300 - c
3 - 10 - 300 - dood
3 - 20 - 100 - a
3 - 20 - 100 - b
3 - 20 - 100 - c
3 - 20 - 100 - dood
3 - 20 - 200 - a
3 - 20 - 200 - b
3 - 20 - 200 - c
3 - 20 - 200 - dood
3 - 20 - 300 - a
3 - 20 - 300 - b
3 - 20 - 300 - c
3 - 20 - 300 - dood
3 - 30 - 100 - a
3 - 30 - 100 - b
3 - 30 - 100 - c
3 - 30 - 100 - dood
3 - 30 - 200 - a
3 - 30 - 200 - b
3 - 30 - 200 - c
3 - 30 - 200 - dood
3 - 30 - 300 - a
3 - 30 - 300 - b
3 - 30 - 300 - c
3 - 30 - 300 - dood
4 - 10 - 100 - a
4 - 10 - 100 - b
4 - 10 - 100 - c
4 - 10 - 100 - dood
4 - 10 - 200 - a
4 - 10 - 200 - b
4 - 10 - 200 - c
4 - 10 - 200 - dood
4 - 10 - 300 - a
4 - 10 - 300 - b
4 - 10 - 300 - c
4 - 10 - 300 - dood
4 - 20 - 100 - a
4 - 20 - 100 - b
4 - 20 - 100 - c
4 - 20 - 100 - dood
4 - 20 - 200 - a
4 - 20 - 200 - b
4 - 20 - 200 - c
4 - 20 - 200 - dood
4 - 20 - 300 - a
4 - 20 - 300 - b
4 - 20 - 300 - c
4 - 20 - 300 - dood
4 - 30 - 100 - a
4 - 30 - 100 - b
4 - 30 - 100 - c
4 - 30 - 100 - dood
4 - 30 - 200 - a
4 - 30 - 200 - b
4 - 30 - 200 - c
4 - 30 - 200 - dood
4 - 30 - 300 - a
4 - 30 - 300 - b
4 - 30 - 300 - c
4 - 30 - 300 - dood

[download]


-InjunJoel
"I do not feel obliged to believe that the same God who endowed us with sense, reason and intellect has intended us to forego their use." -Galileo

In reply to Re: Creating a Dynamic Nested Loops for HoA by injunjoel
in thread Creating a Dynamic Nested Loops for HoA by monkfan

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