From: jsa@alexandria.organon.com (Jon S Anthony)
Subject: Re: maintenance of overriding subprograms
Date: 1997/09/09
Date: 1997-09-09T00:00:00+00:00 [thread overview]
Message-ID: <JSA.97Sep9132250@alexandria.organon.com> (raw)
In-Reply-To: EG8tAB.Et5@world.std.com
In article <EG8tAB.Et5@world.std.com> bobduff@world.std.com (Robert A Duff) writes:
> In article <34145A2F.3659@pseserv3.fw.hac.com>,
> W. Wesley Groleau x4923 <wwgrol@pseserv3.fw.hac.com> wrote:
> >If your names are well-chosen, and your hierarchy well-designed,
> >wouldn't it be unnecessary (except for the occasional extreme case)
> >to hunt down a lot of other stuff to understand the item at hand?
>
> I don't think so. If I see:
>
> package P is
> type T is new Some_Parent with ...;
> procedure Foo(X: T);
> private
> ...
> end P;
>
> How on Earth am I supposed to know about the 17 primitive operations of
> type T?
Right. You can't without looking them all up. And it gets a _lot_
worse with MI. This is just the old problem of OO (typically swept
under the rug by OO fanatics) that it can cause all sorts of
maintenance problems.
> >Conversely, if one has to study all the ancestors in great detail
> >to do anything with a particular descendant, haven't we lost much of
> >the reduced work alleged to be acheived by inheritance?
IMO, reducing work is not and never really has been a benefit of OO.
That's not what its good for.
> Well, not really. For example, think of all those clients of the
> *parent* type that happily use the derived type without even *knowing*
> about it.
And possibly shooting themselves in the foot and generating all sorts
of maintenance nightmares to where the whole thing collapses under its
own bloated opaque weight.
> It depends who's doing the "alleging", I guess. It ranges from "OOP
> is a useful tool" to "OOP will cure all the world's ills". ;-)
To "OOP is outright dangerous" if not handled very carefully.
/Jon
--
Jon Anthony
OMI, Belmont, MA 02178, 617.484.3383
"Nightmares - Ha! The way my life's been going lately,
Who'd notice?" -- Londo Mollari
next prev parent reply other threads:[~1997-09-09 0:00 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
1997-09-02 0:00 maintenance of overriding subprograms Stephen Leake
1997-09-05 0:00 ` Robert Dewar
1997-09-05 0:00 ` Stephen Leake
1997-09-05 0:00 ` Matthew Heaney
1997-09-07 0:00 ` Robert A Duff
1997-09-08 0:00 ` Tom Moran
1997-09-08 0:00 ` Stephen Leake
1997-09-08 0:00 ` W. Wesley Groleau x4923
1997-09-09 0:00 ` Robert A Duff
1997-09-09 0:00 ` Jon S Anthony [this message]
[not found] ` <340DCE1D.6C5F@bix.com>
1997-09-04 0:00 ` John G. Volan
1997-09-07 0:00 ` Robert Dewar
1997-09-08 0:00 ` Robert A Duff
1997-09-09 0:00 ` Dan Johnston D.B.
1997-09-09 0:00 ` W. Wesley Groleau x4923
1997-09-09 0:00 ` Tom Moran
1997-09-10 0:00 ` Robert Dewar
1997-09-11 0:00 ` Dan Johnston D.B.
1997-09-12 0:00 ` Robert Dewar
1997-09-12 0:00 ` Richard A. O'Keefe
1997-09-12 0:00 ` Samuel Mize
1997-09-18 0:00 ` Shmuel (Seymour J.) Metz
1997-09-24 0:00 ` John G. Volan
1997-09-25 0:00 ` Shmuel (Seymour J.) Metz
1997-09-26 0:00 ` Richard A. O'Keefe
1997-09-10 0:00 ` Anonymous
-- strict thread matches above, loose matches on Subject: below --
1997-09-10 0:00 Marc Wachowitz
1997-09-29 0:00 Marin David Condic, 561.796.8997, M/S 731-96
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