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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fac41,2c6139ce13be9980 X-Google-Attributes: gidfac41,public X-Google-Thread: 1108a1,2c6139ce13be9980 X-Google-Attributes: gid1108a1,public X-Google-Thread: f43e6,2c6139ce13be9980 X-Google-Attributes: gidf43e6,public X-Google-Thread: 103376,3d3f20d31be1c33a X-Google-Attributes: gid103376,public From: Brian Rogoff Subject: Re: Interface/Implementation (was Re: Design by Contract) Date: 1997/09/16 Message-ID: #1/1 X-Deja-AN: 273121920 References: X-Trace: 874461509 29521 (none) 206.86.0.12 Newsgroups: comp.object,comp.software-eng,comp.lang.ada,comp.lang.eiffel Date: 1997-09-16T00:00:00+00:00 List-Id: On Sat, 13 Sep 1997, Patrick Doyle wrote: > In article , > Jon S Anthony wrote: > > > >In article doylep@ecf.toronto.edu (Patrick Doyle) writes: > > > >> Ok. I'll go for that, because my argument all along has been that > >> abstract superclasses can do as much as *and more than* Ada specs. > >> So let's consider just the export aspects of an abstract class. Is > >> there anything that they can't do which Ada specs can do? > > > >Yes, _of course_ there is. An Ada spec. can bundle and export _many_ > >different interfaces. These can be abstract and/or concrete. > > An abstract class could have some concrete features. Is that > similar? No. I don't want to second-guess Jon, but one of the things you can do in Ada is have a (generic package) spec with no body. Read the Ada Rationale, in particular 12.6, for examples. After you understand this, we can discuss the similarities and differences between package specs and abstract classes at a higher level. > You're right that I should be more experienced with Ada, but I'll > have to disappoint you on the "not saying anything more" front. :-) That's fine, just don't expect anyone to take what you are saying seriously until you've read the (easily and freely available) description of Ada 95. BTW, where is the free version of OOSC II that I can peruse for these discussions? ;-). -- Brian