OK, here's a version that just does the iteration, but it uses coroutines (which I just taught myself for this puzzle, so bear with me): 
#!/usr/bin/pugs

use v6;

sub NL2 (++@loop) {
    coro {
        given (@loop.elems) {
            when 0  { yield [] }
            when 1  { @loop[0].map:{ yield [$^first] }; yield undef }
            default {
                for @loop[0] -> $first {
                    my &rest = NL2(loop => @loop[1..Inf]);
                    my @rest;
                    while @rest = rest() {
                       yield [$first, @rest];
                    }
                }
                yield undef;
            }
        }
    }
}


my &iter = NL2(loop => ([0..2], [3..5], [6..8]));
my ($cnt, $item);

say "ITER {++$cnt}: {$item.perl}" while $item = iter;

[download]
Now to add the other params . . .

In reply to Re: Perl6 Contest #2: P6 That Doesn't Look Like P5 by geoffb
in thread Perl6 Contest #2: P6 That Doesn't Look Like P5 by Limbic~Region

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