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From: ncmagel@ndsuvax.UUCP (ken magel)
Newsgroups: net.lang.ada
Subject: inheritance
Message-ID: <241@ndsuvax.UUCP>
Date: Tue, 12-Aug-86 07:20:30 EDT
Article-I.D.: ndsuvax.241
Posted: Tue Aug 12 07:20:30 1986
Date-Received: Fri, 15-Aug-86 20:40:08 EDT
Organization: North Dakota State University, Fargo, ND
List-Id: <comp.lang.ada>


   If I have read the ADA Reference Manual correctly, it seems that ADA(r)
does support inheritance of the form used in Smalltalk-80 and other object
oriented languages.  The inheritance occurs when one declares a new derived
type which then inherits all the operations already existing for the type
from which it was derived.  One can use blocks to redefine operations if desired
One restriction is that the original subtype must be defined in a package and
the inherited operations are those defined in the package.  This seems to 
correspond almost exactly to the class of Smalltalk-80 even to the extent of 
supporting class variables.  If the packages involved were generic, one could
even build a system of classes and instances, each with their own variables
similar to the way object oriented programs are usually constructed.