Doing weird things with objects in Perl

function_obj.pl

#!/usr/bin/env perl

package Foo {
  use Mojo::Base '-base';
  sub new {
    my $class = shift;
    my $store = {};
    bless sub {
      my $opt = shift;
      $store->{base} //= $class->SUPER::new;
      return $opt && exists $store->{$opt} ? $store->{$opt} : $store;
    }, $class;
  }
  sub bar {
    my ($self) = shift;
    return $self;
  }
}

my $f = Foo->new;
print '$f                 = ' . $f . "\n";
print '$f->()             = ' . $f->() . "\n";
print '$f->("base")       = ' . $f->("base") . "\n";
print '$f->bar            = ' . $f->bar . "\n";
print '$f->("base")->bar  = ' . $f->("base")->bar . "\n";