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From: mitchell@community-chest.uucp (George Mitchell)
Newsgroups: comp.sw.components
Subject: Re: Seeing component source code?
Message-ID: <75860@linus.UUCP>
Date: 25 Oct 89 12:51:23 GMT
References: <67790@tut.cis.ohio-state.edu> <130200016@p.cs.uiuc.edu>
Sender: news@linus.UUCP
Reply-To: mitchell@community-chest.UUCP (George Mitchell)
Organization: MITRE-McLean Software Engineering Laboratory
Lines: 25

Until your last posting you were only getting close, but now you have
really "pushed my button".
In article <130200016@p.cs.uiuc.edu> johnson@p.cs.uiuc.edu writes:
>
>To raise a last point, we probably disagree on what a component is.
>I don't believe in the mythology that we will be able to reuse
>components without changing them.  It is very hard to predict how
>people will want to change components, so it is very hard to know
>what information to hide.  Components include abstract classes and
>frameworks, which are really just partial programs.  This makes it
>even harder to make provide specifications that are different from
>the code, significantly simpler, and useful.
>
At OOPSLA '89 the statement was made (I wish that I had said it) that
modifying [code/component] was not reuse but recycling.  Since the cost
of producing code is a small portion of the total lifecycle cost, the
goal of reusing complete components should not be so quickly abandoned.
The potential savings in testing and maintenance are well worth while.
If this requires extensive domain analysis, system designs constrained
by component availability, and use of languages supporting inheritance,
the benefits should usually be well worth the sacrifices.
--
/s/ George   vmail: 703/883-6029
email:  mitchell@community-chest.mitre.org    [alt: gmitchel@mitre.arpa]
snail:  GB Mitchell, MITRE, MS Z676, 7525 Colshire Dr, McLean, VA  22102