Re^3: Unusual Closure Behaviour

[shmem]

This place needs you.

So true.

What happens here? Does this mean that each scratchpad is persistent at its recursion level?

use strict;
sub foo;
sub foo {
    return unless $_ [0];
    my $x if undef;
    print ++ $x, " ";
    foo $_ [0] - 1;
}
foo 1; print "\n";
foo 2; print "\n";
foo 3; print "\n";
foo 7; print "\n";
foo 11; print "\n";
foo 9; print "\n";
foo 15; print "\n";
__END__
1 
2 1 
3 2 1 
4 3 2 1 1 1 1 
5 4 3 2 2 2 2 1 1 1 1 
6 5 4 3 3 3 3 2 2 
7 6 5 4 4 4 4 3 3 2 2 1 1 1 1