[Modules] DeltaClass

Stephen Pair spair at advantive.com
Mon May 6 04:45:00 UTC 2002


I think DeltaClass should be reworked a little bit in terms of where it
exists in the class hierarchy.  Here are a couple of observations about
DeltaClass:

 - it is used to record changes to a class (hence the name)
 - it is a subclass of Class
 - it serves as a delta for both classes and metaclasses
 - it (AFAICT) does not act as a Behavior

The class hierarchy currently looks like:

ProtoObject
  Object
    Behavior
      ClassDescription
        Class
          DeltaClass

Based on these observations, I would consider that DeltaClass not
subclass Class, and be split into three classes as follows:

ProtoObject
  Object
    DeltaDescription
      DeltaClass
      DeltaMetaclass

I probably would change the names as follows (but this is a minor
thing):

ProtoObject
  Object
    DeltaDescription
      ClassDelta
      MetaclassDelta

But, this is just based on a cursory examination of DeltaClass.  Is
there significant behavior needed from its superclasses that would make
this change problematic?

- Stephen




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