Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!iuvax!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu!m.cs.uiuc.edu!johnson
From: johnson@m.cs.uiuc.edu
Newsgroups: comp.software-eng
Subject: Re: Orphaned Response
Message-ID: <39400112@m.cs.uiuc.edu>
Date: 8 Jul 90 03:21:00 GMT
References: <749@<26855613>
Lines: 27
Nf-ID: #R:<26855613:749:m.cs.uiuc.edu:39400112:000:1375
Nf-From: m.cs.uiuc.edu!johnson    Jul  7 22:21:00 1990


tom@stl.stc.co.uk writes:
>In article <26855613.749b@petunia.CalPoly.EDU> jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes:
>>
>>A lot of what is gained in OOD is in the de-sequentializing of our problems.
>>Objects can be considered as independently executing processes.  Because of
>>the extreme decoupling between objects, the problem is broken down into
>>more manageable pieces.  This seems to me that it should make the problem
>Every OO language I have seen makes this claim. However, every OO language
>that I've seen (with one experimental exception, a laboratory toy language)
>insists that the messages are SYNCHRONOUS, that the channels between the 
>processes are UNBUFFERED (and blocking), that every message has a REPLY
>whose sending is implicit (in result delivery).

There is really no contradiction between these statements.  OOD lets the
designer THINK about objects as if they are desequentialized, it doesn't
require that it be true.  Object-oriented programmers tend not to worry
much about order of execution but rather about interfaces.  This is similar to
 
>           Abstraction with strong encapsulation

I am curious about how software engineers have traditionally practised
>            Inheritance mechanisms to facilitate re-use
I can't see the point you are trying to make.


Ralph Johnson -- University of Illinois at Urbana-Champaign