Man or boy test

Do you know the Knuth's "man or boy" test ? If not, see http://en.wikipedia.org/wiki/Man_or_boy_test that contains explanations and implementations in various languages. A Perl5 implementation is : sub A { my ($k, $x1, $x2, $x3, $x4, $x5) = @_; my $B; $B = sub { return A(--$k, $B, $x1, $x2, $x3, $x4); }; return &$x4() + &$x5() if ($k <= 0); return &$B(); } print A(10, sub{1}, sub{-1}, sub{-1}, sub{1}, sub{0}), "

"; # the expected result is -67 In r32377, I commit a Lua implementation that works on Parrot. Can we do a Perl6 implementation with the current Rakudo ? François.