Here's a prettier way to write the Perl 6 solution: 
sub group (*@array is copy) {
    gather {
        while @array {
            take [
                gather {
                    my $h = shift @array;
                    take $h;
                    while @array and $h eq @array[0] {
                        take shift @array;
                    }
                }
            ];
        }
    }
}

[download]
It would be slightly prettier if take could harvest a value en passant.

In reply to Re^2: 99 Problems in Perl6 (Lisp, Prolog, Haskell) by TimToady
in thread 99 Problems in Perl6 by Ovid

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