Re: Clean Object Class Design -- What is it?

Carl Rosenberger wrote:
>
> Lee Fesperman wrote:
> > In all the OO systems I've seen, everything is built with single direction
 linking -
> > (pointers, references, composite objects). Inheritance is even worse; it
 is purely
> > hierachical.
>
> Although I agree with you in principal, I would like to point out that
> navigating from attributes to parents is possible in object databases by
> using queries.

Well, I did mention later that the real problem was having to use a different technique for going 'backwards'.

> I would not see *multiple* inheritance as purely hierarchical, by the way.
> For those of us that store Java objects and their attributes, it would be
> beautiful if the "interface" concept would allow declaring common member
> fields.

Sorry, I think I overreached. I probably shouldn't have said 'purely'. I meant it is primarily a parent-child structure.

> Does anyone have any pointers to a programming language that supports
> navigating from child to parent? Reference count garbage collectors could
> easily support this feature, but as I understand they are not
> state-of-the-art.

I used a parent-child link as an example. There may be multiple parent or maybe other types of links.

-- 
Lee Fesperman, FFE Software, Inc. (http://www.firstsql.com)
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