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Date: 24 Apr 92 14:47:59 GMT
From: psinntp!bony1!richieb@uunet.uu.net  (Richard Bielak)
Subject: Re: Ada vs. C++ Paper (was Re: Why ADA?)
Message-ID: <1992Apr24.144759.20298@bony1.bony.com>
List-Id: <comp.lang.ada>

In article <1992Apr17.170925.1406@ennews.eas.asu.edu> koehnema@enuxha.eas.asu.e
du (Harry Koehnemann) writes:

[...]

>It seems that the real problem is that no one has done a real good job
>completely defining the semantics of inheritance.  Eiffel didn't get this
>correct in its early versions either and the last Eiffel compiler (they
>have new versions almost bi-annually) I used completely fell apart when
>multiple inheritance was brought into the picture (internal compiler
>errors when renaming with multiple inheritance).
>--
>Harry Koehnemann
>koehnema@enuxha.eas.asu.edu

I've used ISE's Eiffel 2.3 compiler. The problem you describe is with
_repeated_ inheritance, not multiple inheritance. 

The semantics of inheritance are defined very precisely in Eiffel
(see "Eiffel: The Language" by Betrand Meyer), however they are
difficult to implement.

When I discussed this with B. Meyer, he said that the main reasons 
ISE Eiffel 2.3 compiler has these bugs, is because the compiler was 
written in C :-).

Eiffel 3.0, due out this year, was re-written in Eiffel, so repeated
inheritance should work properly.


...richie




-- 
* Richie Bielak   (212)-815-3072   | "Your brain is a liquid-cooled parallel  *
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