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From: donh@syd.csa.com.au (Don Harrison)
Subject: Re: Safety-critical development in Ada and Eiffel
Date: 1997/07/22
Message-ID: <EDp5Hq.52w@syd.csa.com.au>#1/1
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Newsgroups: comp.object,comp.software-eng,comp.lang.ada,comp.lang.eiffel
Date: 1997-07-22T00:00:00+00:00
List-Id: <comp.lang.ada>


Robert Dewar wrote:

:Don said
:
:<<Interestingly, this issue reveals a benefit of unifying module and type.
:A unified model that dictates unique class names (eg. Eiffel's) simplifies
:things by allowing class names to serve a twofold purpose in clients -
:>>
:
:
:Time to restate the following observation:
:
:Unify and Confuse both mean at their root the same thing, namely to
:make into one, or to join together, but they express a different
:judgment as to the desirability of of the joining.

Yes, the perspective *does* depend on a judgement of the desirability of 
unification vs. separation in any particular case considered. However, it's a
mistake to assume that a judgement is necessarily arbitrary. On the contrary, 
an informed judgement can be made on the basis of the relative pros/cons of 
each alternative. These pros and cons can be weighted on the basis of 
importance and used to construct a formula for desirability of unification/
separation. Among those qualities I would regard as important are such things 
as simplicity, reusability and reliability. Any rational person will agree 
these are important qualities in software. Pros which promote these qualities
would be heavily weighted as would be cons which compromised them.

Such a formula would provide a fairly objective basis for judgement which 
transcends the "This-is-what-I'm-used-to-so-it-must-be-better mentality".

I don't have the time to do this but it would be an instructive exercise 
given Eiffel's enhancement of the above qualities.


(Don certainly had nothing new to say on this issue, and neither
:do I :-)

There is more to say, but perhaps another day.. :)


Don.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Don Harrison             donh@syd.csa.com.au