On 25-Nov-2008, at 10:58 PM, Vassili Bykov wrote:
>
> And thus the fragile superclass problem is born.

:-)

> The thing is, there are two overlapping but different perspectives
> here. From an object-centric view, sure, any state or behavior is
> there in the object and where in the hierarchy it comes from is a
> minor detail.
>
> However, as far as the code goes, we are talking about distinct chunks
> of code, potentially written, maintained and updated by different
> people. A subclass depends on the superclass in the same way that code
> using a library is a dependent of that library's API. Managing that
> dependency has maintainability repercussions, and weakening it is a
> good thing.


If my memory isn't failing me too much I seem to remember going to a  
talk about a dozen years ago by Adele Goldberg where she talked about  
the need to form contracts between producers and consumers of class  
definitions.

-- 
					Greg A. Woods; Planix, Inc.
					<woods at planix.ca>

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