Recursive closure


I was wondering if it could be possible for a sub to return a recursive closure. Of course this turns out to be possible, although, to the best of my efforts, not in "one step", see e.g. the following code:

sub mkrecsub {
    my $k=shift;
    my @memoize = ( $k => [0,1] );
    my $tmp = sub {
      my ($n, $func) = @_;
      return $memoize[$k][$n] if defined $memoize[$k][$n];
      $memoize[$k][$n] = $func->($n-1, $func) + $func->($n-2, $func);
    sub { $tmp->(shift, $tmp) };

my $Fib = mkrecsub(1);
print $Fib->($_) for 1..73;

Now I wonder if there is/could be (could not find any!) some sort of identifier that refers to the current (anomynous) sub; say, something like __SUB__ or __THIS__, to be used like this:

  sub {

Michele Dondi's original post