[Python-Dev] type categories

[Andrew Koenig]

>> Remember that one thing I consider important is the ability to claim
>> that classes written by others belong to a category defined by me.  I do not
>> want to have to modify those classes in order to do so.

Oren> How about union(int, long, float, has_marker("TotallyOrdered")) ?

How about it?  There is still the question of how to make such claims.

Oren> Inheritance of implementation also inherits the form (methods
Oren> and call signatures). If you don't go out of your way to modify
Oren> it a subclass will usually also be a subcategory so this should
Oren> be pretty transparent most of the time.

Right.  So how do you define a subclass that you do not want to be
a subcategory?