#!perl -l
use strict;
package Base;

sub package_attrs : lvalue {
  my $self=shift;
  my $caller=shift || caller or die "For use by subclasses only\n";
  $self->{$caller}
}

sub new {
  my $class=shift;
  my $self=bless {},$class;
  $self->init(@_);
  return $self;
}

sub init {
	my $self=shift;
	my %params=@_;
	$self->package_attrs=\%params;
	return $self;
}

package Base::Sub;
our @ISA=qw(Base);
sub init {
	my $self=shift;
	my ($x,$y,$z)=(shift,shift,shift);
	$self->package_attrs={foo=>$x,bar=>$y,baz=>$z};
	$self->SUPER::init(@_);
	return $self;
}

sub foo {
  my $self=shift;
  my $attrs=$self->package_attrs;
  return @_ ? (($attrs->{foo}=shift),$self) : $attrs->{foo}
}

package Base::Sub::Woofer;
our @ISA=qw(Base::Sub);
sub init {
	my $self=shift;
	my ($x,$y,$z)=(shift,shift,shift);
	$self->package_attrs={foo=>$x,bar=>$y,baz=>$z};
	$self->SUPER::init(@_);
	return $self;
}

sub bar {
  my $self=shift;
  my $attrs=$self->package_attrs;
  return @_ ? (($attrs->{bar}=shift),$self) : $attrs->{bar}
}

package main;
use Data::Dumper;
my $obj1=Base->new(foo=>"Delicious");
my $obj2=Base::Sub->new(1,2,3,foo=>"Delicious");
my $obj3=Base::Sub::Woofer->new(10,20,30,1,2,3,foo=>"Delicious");
$obj3->package_attrs="foo";
print Dumper($obj1,$obj2,$obj3);