Re: Clean Object Class Design -- Circle/Ellipse

<D_at_B.A> wrote in message news:QLG57.872$Y47.13304_at_www.newsranger.com...
> In article <9TF57.167$%16.43276332_at_radon.golden.net>, Bob Badour says...
 

> 1. Is the case Square/Rectangle really similar to Circle/Ellipse?
> [...]

It is not similar. It is the *same* .
The problem that occurs when taking the spec into a solution, and therefore coming to
grief with the Liskov Substitution Principle (LSP) , was called by Peter Wegner
"subset subtyping" .

Go to Google etc to search comp.object for the full name of the paper by Wegner
that discusses the problem. Follow the thread to see what potential impl solutions can
be used to alleviate the problem

BTW, not sure why comp.theory is on the list. But be warned, once you get those guys involved, what you'll get as "theory" will
make the comp.object debates look like Janet and John book 2 ... :-)

Regards,
Steven Perryman Received on Fri Jul 20 2001 - 04:36:04 CDT