Re: Clean Object Class Design -- Circle/Ellipse

Bob Badour wrote:
> > I know Smalltalk more than a little well.
> > And James Robertson (who knows a thing or
> > two about Smalltalk :-) agreed with me that you
> > were incorrect.
>
> Big deal. Ask him to point to any Smalltalk language definition that defines
> "instance" as anything other than a variable which one can reference.

Well for starters the following three descriptive pages each contain many desriptions of "objects" and "instances of classes", all of which are clearly shown to exist independently from variables.  

  http://www.mucow.com/squeak-qref.html
  http://kaka.cosc.canterbury.ac.nz/~wolfgang/cosc205/smalltalk1.html
  http://www.objs.com/x3h7/smalltalk.htm

I wonder if perchance you are confused between "instance" and "instance variable"? The latter, of course, is smalltalk terminology for what others call an "attribute". Yes, an instance variable, being an attribute,
is certainly a (scoped) variable that one can reference. (tho' even so you'd still be wrong since the reflection capabilities allows the programmer to access it as an offset rather than a variable)

> An instance or variable can have the value 5. The value, however,
> is not an instance.

It's an instance of SmallInt, as you can easily discover by inspecting it (inspector window normally puts the class on its title bar). From within its inspector window, you can send it any message that is handled by the SmallInt protocols, and it will respond as if it were an instance of the class SmallInt. Which indeed it is.

> According to the definition of the Smalltalk language an instance
> is a variable that one can reference. One cannot reference a value.
> Values are self-identifying.

This is simply untrue, and it couldn't possibly make sense. Mr Badour is clearly confused about the concepts of variable, value, reference, object, class, and instance.

> Anyone with access to a browser and Google can verify for
> themselves that Smalltalk defines "instance" as a variable
> that one can reference.

The three links above contradict you. I found them in 2 mins with Google.

> ..you have no interest in learning or in
> communicating -- instead, you have an interest in attacking and
> destroying. I find little merit in your goals.

I cannot see how Bob Badour can make such a claim. He has made a bunch of completely untrue assertions and refuses to accept quite reasonable explanations from people with reasonable communication skills. It should be obvious to whom the comment "no interest in learning or in communicating" really applies. Received on Mon Oct 01 2001 - 12:19:13 CEST