sub make_iter_deeperer {
    my @AoA = @_;
    my @idx;
    my $i = -1;
    $idx[0] = -1;
    my @return;

    return sub {

        # depth first to produce "nested" result behavior
        # if we aren't at the end of AoA's elements, go to
        # the next, reseting the next elements' index
        if(  $i < $#AoA  ) {
                $idx[++$i]= -1;
        }

        LOOP: {
            if ( ++$idx[$i] > $#{@{$AoA[$i]}} ) {
                # if the index of the array i'm working in is
                # past the end of elements it means we need to
                # go up a level and clear the last return value
                pop @return;

                # we may have finished everything
                return if --$i < 0;

                # we may have finished more than one
                # so check again
                redo LOOP;
            }
            # if not, put the next element in the return value
            else {
                $return[$i] = $AoA[$i][$idx[$i]]
            }
        }
        return @return;
    }
}