From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=BAYES_00,INVALID_DATE autolearn=no autolearn_force=no version=3.4.4 Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!nstn.ns.ca!news.cs.indiana.edu!spool.mu.edu!sol.ctr.columbia.edu!IDA.ORG!wheeler From: wheeler@IDA.ORG (David Wheeler) Newsgroups: comp.lang.ada Subject: OOP & Ada.. Message-ID: <1991May31.201529.8466@IDA.ORG> Date: 31 May 91 20:15:29 GMT Organization: IDA, Alexandria, VA List-Id: chuck@brain.UUCP (Chuck Shotton): =I'd like YOU to explain to netland how to support dynamic inheritance at =runtime in Ada without resorting to manually-supported coding conventions. = =I've had a direct hand in the management, design, and implementation of =about 250,000 lines of Ada over the past 2 or 3 years on NASA's SSE =contract. We used OOD techniques such as Buhr diagraming, etc. and =coded according to the design. BUT THAT DOESN'T MAKE THE CODE OBJECT ORIENTED. = =The whole point of the comparison between C++ and Ada hinges on the =semantic interpretation of the term "object-oriented." To most =Ada-literate individuals, "object-oriented" refers to the concepts of =information hiding and specific design methodologies. To others (C++, =academia, etc.) "object-oriented" connotes message passing, =inheritance, dynamic binding, methods, classes, etc. Ada does NOT =provide direct support via language constructs and run-time behavior to =support all of these concepts. The burden is placed on the programmer =to implement "message passing" and there is no way to safely =(consistenly) implement dynamic binding. = =Rather than degenerate into a "mine's bigger than yours" comparison of =two vastly different languages (and programming paradigms), it would be =more constructive to discuss how to implement TRUE object-oriented =features within the current limitations of Ada. I'd be interested in =hearing suggestions for supporting the aforementioned list of "alleged" =object oriented language features using plain vanilla Ada. This could =actually be useful on some real projects. There are at least 3 object-oriented extensions(?) to Ada that I know of: Classic-Ada (SPS in Melbourne, Florida), AOOP (CTA, Rockville, MD; was APOS), and Dragoon (not sure if this is an extension or merely related). One of these might be helpful for those who want Ada & OO *now*, but I only know the names - I haven't used any of them. I don't even know if they're useful or not. Does anyone have any experience _using_ these languages? --- David A. Wheeler wheeler@ida.org Disclaimer: this posting never happened.