package Foo;

use strict;

sub new {
    bless {}, shift();
}

sub do_something {
   my $self = shift;
   my $name = shift || 'foo';
   return make_do_something($name);
}

sub make_do_something {
    my $name = shift;
    return sub {
        my $self = shift;
        print "Foo $name!!!\n";
    }
}

1;

##############################################

package Bar;

use strict;
use base 'Foo';

sub new {
    bless {}, shift();
}

sub do_something {
   my $self = shift;
   return $self->SUPER::do_something('bar');
}

1;