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Date: 6 Nov 92 09:00:41 GMT
From: agate!doc.ic.ac.uk!uknet!root44!hrc63!mrcu!paj@ames.arc.nasa.gov  (Paul J
ohnson)
Subject: Re: OOD, Ada, and Inheritance
Message-ID: <2169@snap>
List-Id: <comp.lang.ada>

In article <mmaccorm.47@fox.nstn.ns.ca> mmaccorm@fox.nstn.ns.ca (Mike Mac Corma
ck) writes:
>If Ada software is being designed using OOA and OOD, should inheritance be 
>avoided (or prohibited) in the design process, as Ada does not provide 
>inheritance? 

Good question.  If no-one has any other questions then class is
dismissed :-)

I recall that ADA's genericity system allows you to pass functions and
procedures as parameters in a way reminiscent of the C function
pointers (although ADA is type-safe).  I would look into the
possibility of simulating inheritance by setting up structures of
functions when objects are created.  You should be able to get single
inheritance without too much trouble.  Maybe an ADA guru can suggest
some details.

One system built in this way is the X Intrinsics library (Xt).  Its
built in C, but the principle remains the same.  Take a look at it for
an idea of what I mean.

Paul.
-- 
Paul Johnson (paj@gec-mrc.co.uk).	    | Tel: +44 245 73331 ext 3245
--------------------------------------------+----------------------------------
These ideas and others like them can be had | GEC-Marconi Research is not
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