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

In article <swr57.116$9G4.39170200_at_radon.golden.net>, Bob Badour says...
>
>>>I see that Chris Date recently published an excellent article on the
>>>circle/ellipse issue at http://www.dbdebunk.com/
>>>
>>Excellent? Just a terminology assault; I personally learned nothing from
 this
>>article.
>
>Could your dismissal of the article as a terminology assault have
>contributed to your failure to learn anything?

If you advocate rigorous models, what did you found so attractive about the article? Does it establish one? Does it explain LSP paradox? OK, a circle is always a subclass of ellipse, I agree, but is the article convincing enough for majority of comp.object? I'm bored of discussions if type and class are the same or not, it's time to move on.

>>On the other hand, noisy newsgroup comp.object provided some valuable
>>facts, for example, calculating ellipse lenghth is fundamentally more
 expensive
>>than that of circle.
>
>All the more reason to allow polymorphism so your ellipse variable can
>actually have a circle value and sometimes use the less expensive length
>calculation.

Yes, but unless you have an example like this, somebody might always think that there is little reason to override methods at all. Good article would include it. Received on Thu Jul 19 2001 - 04:43:04 CEST