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From: Magnus.Kempe@di.epfl.ch (Magnus Kempe)
Newsgroups: comp.lang.ada
Subject: Re: Mut. Recurs. in Ada9X w/o Breaking Encaps.?
Date: 3 Oct 1994 08:07:41 GMT
Organization: Ecole Polytechnique Federale de Lausanne
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Keywords: Ada 9X, C++, Eiffel, Smalltalk, object-oriented
Date: 1994-10-03T08:07:41+00:00
List-Id: <comp.lang.ada>

jgv@swl.msd.ray.com (John Volan) writes:
: 
: [summary--packages should be broken up in three, not two, parts:
:  specification, body, and "abstract".]

John,

I suggest you stop for a while, and take the time to examine the
solutions which have been offered (and read the RM 9X, clause 10.1,
on program structure/separate compilation).

Child units are _essentially_ a means to break packages into parts.  This
is something _no_ other language offers, so it is quite understandable that
many will not always immediately see how useful it is (and some are likely
to abuse it, as I tend to :-).

The final solution whch Norm presented solves _perfectly_ the problem you
submitted, with abstract types, class-wide subprograms, and a hierarchy of
packages.

Of course, Ada is not Smalltalk.  But then, Smalltalk is not Ada either.
In other words: Don't try to blindly transfer programming patterns from one
language to another.

-- 
Magnus Kempe		"I know not what course others may take, but as for me,
Magnus.Kempe@di.epfl.ch  Give me Liberty... or give me Death!" -- Patrick Henry