use Perl

Hi,

I thought you might be interested to look at the meta-model of the Joose 3.0. Joose is a very close port of Moose to JavaScript. And its sources are much clearer and easier to understand )

It starts with the abstract property:
http://github.com/Joose/Joose/blob/mutability/lib/Joose/Managed/Property.js

And abstract property set (isa property):
http://github.com/Joose/Joose/blob/mutability/lib/Joose/Managed/PropertySet.js

Then defines some kind of "property set algebra", with couple of operations defined: flattening and composition.
Flattening is what happens between roles, when they are listed in the class (produces a new property set), and composition is what happens between class and role.

The whole project can be found here:
http://github.com/Joose/Joose/tree/mutability

And documentation is "borrowed" from Moose :)
http://joose.github.com/Joose/doc/html/Joose/Manual.html

There is an implementation limitation though - Joose supports only one superclass (to fit well into prototype nature of JavaScript)

Regards, Nickolay