I'm looking for the right OO approach to what I think amounts to perl 6 roles.

I have an Object base class which is inherited by other objects eg User, Group, Image. When each of these is loaded, they register their Type with the Object class so that any object can be retrieved using the parent class and blessed into the right package.

    sub find {
        my $object = __PACKAGE__->retrieve_object($id);
        bless $object,$object->type->class
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An Object can never exist on its own - it must always be blessed into a child class.

Group is a child class, and any object (including Groups) can be a member of a Group. Also, every object has a default Group (eg User automatically belongs to the group all_users).

Requirements

• It makes sense to store these default Groups as singletons in a hash so that they don't have to be recreated for every object.
• I would also like a method groups() in each child class which asks the Group class for a list of relevant groups.

So, as I see it, I need to:

1. register each child class with the Group class (so that it knows what the default group is, and
2. have some form of code reuse so the the groups() method doesn't need to be included in each child class.

I thought of doing something like this:

    use Group 'default_group'
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Then in the package Group:

sub import {
    my $default_group = $_[1];
    my $callpkg = caller(0);
    register_default_group($callpkg,$default_group);

    no strict 'refs';
    *{$callpkg."::groups"} = \&groups;
    use strict;
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Is this good, bad, ugly? Beauty, truth and love appreciated

thanks
clint

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