Perl can do something that closely resembles an optimized tail call, but it only does so if you tell it to. 
sub tail_fact {
    my ($num, $k) = @_;
    return $k->(1) unless ($num);
    @_ = ($num - 1, sub { return $num * $k->(shift); });
    goto &tail_fact;
}

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In reply to Re^4: (Perl6) Groking Continuations (iterators) by Anonymous Monk
in thread (Perl6) Groking Continuations by crenz

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