Re: Clean Object Class Design -- Circle/Ellipse

From: Graham Perkins <gperkins_at_dmu.ac.uk>
Date: Thu, 11 Oct 2001 10:57:30 +0100
Message-ID: <3BC56D0A.BC80A70A@dmu.ac.uk>

Bob Badour wrote:
> ..
> If Smalltalk made sufficient distinction between values and variables

It makes perfect such distinction.

> one would not need to override setFoci in the Circle class because it
> would never inherit the method. Circle values would inherit the
> operations on Ellipse values but Circle variables would not inherit
> the operations on Ellipse variables.

Oh you really are confused. I can see where now, but not sure if I can explain it.

However, the solution which would remove your problem would be to clearly distinguish between mutable and immutable objects. It's a matter of how you design the classes, and absolutely nothing to do with any particular issues of variables and values in Smalltalk or any other language.

-------------+ http:/www.mk.dmu.ac.uk/~gperkins Received on Thu Oct 11 2001 - 04:57:30 CDT