And for completeness, the glob solution, which spends more code fixing up the output than actually generating the results: 
sub qm {
    my ($glob) = @_;
    my @rv;
    $glob =~ s/(\w+)/{$1,}/g;

    for my $combo (glob($glob))
    {
        $combo =~ s/^:+//;
        next unless length($combo);
        push @rv, join ':', split /:+/, $combo;
    }

    return @rv;
}

[download]
and is horribly slow as well.

BTW, it's interesting to note the change in benchmark results when the input is a long list of null strings: 

$source = ':'x20;

[download]

-QM
--
Quantum Mechanics: The dreams stuff is made of

In reply to Re: possible combinations in sequence by QM
in thread possible combinations in sequence by ruzam

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