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From: bobduff@world.std.com (Robert A Duff)
Subject: Re: Invoking parental methods (was: Java vs Ada 95)
Date: 1996/11/06
Message-ID: <E0GI86.BH6@world.std.com>#1/1
X-Deja-AN: 194890348
references: <E0ED6w.24D.0.-s@inmet.camb.inmet.com>
 <E0EIM2.A3p.0.-s@inmet.camb.inmet.com> <1996Nov5.112527.1@eisner>
organization: The World Public Access UNIX, Brookline, MA
newsgroups: comp.lang.ada
Date: 1996-11-06T00:00:00+00:00
List-Id: <comp.lang.ada>


In article <1996Nov5.112527.1@eisner>,
Larry Kilgallen <kilgallen@eisner.decus.org> wrote:
>My problem, again, is maintainability in the face of genealogy shifts.
>Since Ada 95 does not have a mechanism to do it with zero changes
>to the body in the fashion of Macintosh Object Pascal, I am hoping
>for 1.

Use a convention where you always write:

    subtype Parent is Whatever;
    type New_Type is new Parent ...;

Always use the name Parent in your type conversions (as in
"Parent(Param.all)'Access").  Then you can change the parent by changing
one line to "subtype Parent is Something_Else;".  No changes to the body
are needed.

- Bob