Re: Who's referencing my variables?

[tobyink]

They are probably not being referenced from the synbol table, but rather they're being referenced from other lexical variables.

use 5.010;
use strict;
use warnings;

END { say "Finished script; start of global clean-up" };

{
    package noisy;
    use overload q[""] => sub { $_[0][0] };
    sub DESTROY { say "$_[0] is being cleaned up" }
}

# Simple
{
    my $a = bless ['$a'], "noisy";
    say "defined $a";
} # $a gets cleaned up

# Linear refs
{
    my $b = bless ['$b'], "noisy";
    my $c = bless ['$c', $b], "noisy"; # refers to $b
    my $d = bless ['$d', $c], "noisy"; # refers to $c
    say "defined $b, $c, and $d";
} # $b, $c, $d get cleaned up

# Circular refs
{
    my $e = bless ['$e'], "noisy";  # we'll make this refer to $g soon
+!
    my $f = bless ['$f', $e], "noisy";  # refers to $e
    my $g = bless ['$g', $f], "noisy";  # refers to $f
    push @$e, $g;   # create reference cycle
    say "defined $e, $f, and $g";
} # $e, $f, $g cannot be cleaned up