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=-1.9 required=5.0 tests=BAYES_00 autolearn=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!nntp-feed.chiark.greenend.org.uk!ewrotcd!newsfeed.xs3.de!io.xs3.de!news.jacob-sparre.dk!franka.jacob-sparre.dk!pnx.dk!.POSTED.rrsoftware.com!not-for-mail From: "Randy Brukardt" Newsgroups: comp.lang.ada Subject: Re: about inheritance of subtypes and entities (such as constants) related to a type in the same package Date: Thu, 31 May 2018 17:34:23 -0500 Organization: JSA Research & Innovation Message-ID: References: Injection-Date: Thu, 31 May 2018 22:34:37 -0000 (UTC) Injection-Info: franka.jacob-sparre.dk; posting-host="rrsoftware.com:24.196.82.226"; logging-data="26668"; mail-complaints-to="news@jacob-sparre.dk" X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.5931 X-RFC2646: Format=Flowed; Original X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.7246 Xref: reader02.eternal-september.org comp.lang.ada:52825 Date: 2018-05-31T17:34:23-05:00 List-Id: "Dan'l Miller" wrote in message news:c6b68b0d-e9f0-47a8-9692-7cba63ea1000@googlegroups.com... On Tuesday, May 29, 2018 at 5:12:23 PM UTC-5, Randy Brukardt wrote: ... >> long before >> anyone really understood OOP or similar systems. > >Well, there was Simula in the 1960s. Yes, I know that. But hardly anyone understood them. I recall studying Simula at the University of Wisconsin in the programming language class, and the textbook and instructors presented it as an interesting diversion from typical programming. (We also studied Planner and CLU in that class, along with more mainstream things like Lisp.) No one guessed then that a substantial branch of programming was going to grow out it. Regardless of whether Ada 83 called the derived type mechanism "inheritance", it surely was that, and it survives virtually unchanged for all types in Ada 95 and later. Some additional stuff was added to it (especially for tagged types), and some details were nailed down better, but the mechanisms for subprograms in particular are identical. I thought that was a problem during the development of Ada 9x; no one understood derived types at all in Ada 83, and building the entire OOP system on top of them seemed like elevating an obscure bar band to the main stage at Summerfest. Luckily, I was mostly wrong about that. Randy. Randy.