[Openmcl-devel] mop issue

marco mb at bese.it
Sun Oct 3 04:10:47 PDT 2004

rm at fabula.de writes:

> But what is the semantic of such an operation? The cpl provides a 
> topological ordering of a class' superclasses. But in your usecase
> 'super' _isn't_ a superclass of 'bar' (since it's neither a direct
> superclass of bar nor a direct superclass of any of foo's super-
> classes) - that's where the inconsistency lies. Besides the cpl, 
> super/subclasses are linked by means of their DIRECT-SUBCLASSES
> and DIRECT-SUPERCLASSES slots. If you only splice 'super' into the
> cpl class 'foo' these slots won't get updated by the Lisp implentation.
> Err, the first time such an update would happen in your sample repl
> is actually when you create class 'bar': the system has to update 
> foo's subclass slot.  Iff you do what you do your system might end
> up in a rather inconsistent state once you start to redefine classes:
> you might end up with old instances that still have an older generation
> of you class as a class metaobject ....

ok, now it all makes sense. thanks.

Ring the bells that still can ring.
Forget your perfect offering.
There is a crack in everything.
That's how the light gets in.
     -Leonard Cohen

More information about the Openmcl-devel mailing list