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From: Tansel Ersavas <tansel@rase.com>
Subject: Re: OO, C++, and something much better!
Date: 1997/01/25
Message-ID: <32EA2116.5787@rase.com>#1/1
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references: <JSA.97Jan16141937@alexandria>
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 comp.lang.eiffel,comp.lang.ada,comp.lang.c++,comp.lang.smalltalk,comp.object
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Date: 1997-01-25T00:00:00+00:00
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Joachim Durchholz wrote:
> 
> Tansel wrote:
> 
> > Contrary to what people say, type checking is against the nature of
> > object oriented systems development. Remember, in OO, we only care about
> > the interface of the other object. In fact it should be an OO sin to ask
> > the type, because, in theory, we don�t want to get intimate with objects
> > we are interacting apart from their interface. We only want to know the
> > interface.
> 
> There's a misunderstanding here.
> 
> I agree checking should be done on the interface, but I was not aware of
> any difference between type and interface. After all, objects with
> identical interface have the same type for all practical purposes.
> 

For practical purposes type checking in statically typed languages
involve
both structure and the interface. This doesn't take into consideration
that
part of the structure may be private. There are notable exceptions
though


...

> A good type-checking Smalltalk system could work with versioning, so if
> you delete a routine, you actually define a new class with the routine
> deleted. Existing (typechecked) code would continue to work. Of course the
> system should convert as much as possible to the new version of the class
> structure, but if it finds code that uses the delete routine, the
> programmer has to correct it (or the code has to remain on the old version
> level).

Good point. There are still ways to bypass these in run-time though.
 
...
 
> > Why don't you come to Smalltalk Solutions 97? You may see many examples.
> > It is in NY at Marriot Marquis between March 10-13.
> 
> Sorry, that's a bit far from Germany... (domain .de is short for
> "Deutschland").

Ooops, sorry. I didn't notice. 
 
> > This is not true. Smalltalk base is growing very strongly especially in
> > organizations such as banks.
> 
> I didn't want to downplay the growth of Smalltalk. It's just that the
> numbers presented were nearly content-free. I'd very much like to see some
> solid numbers, though.

InfoWorld and IDC are publishing such numbers. If I come across some, I
might 
collect and post them at one stage.
 
> Regards,
> -Joachim
Kind Regards

Tansel 
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