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=ham autolearn_force=no version=3.4.4 X-Google-Thread: a07f3367d7,29d8139471e3f53e X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII Path: g2news2.google.com!news4.google.com!feeder.news-service.com!feeder.news-service.com!85.214.198.2.MISMATCH!eternal-september.org!feeder.eternal-september.org!.POSTED!not-for-mail From: "J-P. Rosen" Newsgroups: comp.lang.ada Subject: Re: Preventing type extensions Date: Wed, 13 Oct 2010 11:06:03 +0200 Organization: Adalog Message-ID: References: <87iq2bfenl.fsf@mid.deneb.enyo.de> <81799aab-a2e8-4390-8f42-abceaa5fc032@m1g2000vbh.googlegroups.com> <5c0d7798-ba09-4bd0-a28f-f1b028cce927@y3g2000vbm.googlegroups.com> <9df21c09-f611-4088-811c-c092452adffc@e20g2000vbn.googlegroups.com> <37ae2382-9f7d-4790-be5f-e380b9220d75@s19g2000vbr.googlegroups.com> <170a6a4f-d441-4f86-8fbf-8f15da34a094@26g2000yqv.googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Injection-Date: Wed, 13 Oct 2010 09:06:30 +0000 (UTC) Injection-Info: mx03.eternal-september.org; posting-host="ROcR33wHbfxNMoxOWlbGJA"; logging-data="9126"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18QbpRPSTp7LedXOekTRl/l" User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; fr; rv:1.9.2.9) Gecko/20100915 Thunderbird/3.1.4 In-Reply-To: <170a6a4f-d441-4f86-8fbf-8f15da34a094@26g2000yqv.googlegroups.com> Cancel-Lock: sha1:e/5MohwPqE9XCBnPGC9uvARYQQo= Xref: g2news2.google.com comp.lang.ada:15474 Date: 2010-10-13T11:06:03+02:00 List-Id: Le 08/10/2010 15:58, Cyrille a �crit : [snip] > Looks to me this is the other way around. for instance, in C++ either > a subprogram is a method or it is what you call a class-wide > operation. That is to say, when your subprogram has a (ref) parameter > of class C, you can pass it an object of any subclass of C and natural > calls to method of that object will dispatch to the appropriate one. > Note also that C++ offers a choice between static dispatch and dynamic > dispatch. My C++ is a bit rusty but here is an example of that. In > this program "subp" is your classwide operation. Hmmm... yes, a subprogram acting on T is specific, and a subprogram acting on *T behaves like a class-wide operation. Anyway, the concept is much clearer in Ada. Of course, I don't mind if what is doable in Ada is also possible in other languages. The question is that class-wide programming is a first-class citizen in Ada, and I think that feature can be used in ways that can make HR systems easier to certify. I expect that to be a main topic for the workshop at SIGAda. To all those reading this thread: whether you are more inclined to my position, Cyril's, or something else, please come and discuss at the workshop at SIGAda! -- --------------------------------------------------------- J-P. Rosen (rosen@adalog.fr) Adalog a d�m�nag� / Adalog has moved: 2 rue du Docteur Lombard, 92441 Issy-les-Moulineaux CEDEX Tel: +33 1 45 29 21 52, Fax: +33 1 45 29 25 00