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: f43e6,2c6139ce13be9980 X-Google-Attributes: gidf43e6,public X-Google-Thread: 1108a1,2c6139ce13be9980 X-Google-Attributes: gid1108a1,public X-Google-Thread: 103376,3d3f20d31be1c33a X-Google-Attributes: gid103376,public From: bobduff@world.std.com (Robert A Duff) Subject: Re: Separation of IF and Imp: process issue? Date: 1997/09/12 Message-ID: #1/1 X-Deja-AN: 271971982 References: <33E9ADE9.4709@flash.net> Organization: The World Public Access UNIX, Brookline, MA Newsgroups: comp.object,comp.software-eng,comp.lang.ada,comp.lang.eiffel Date: 1997-09-12T00:00:00+00:00 List-Id: In article , Jon S Anthony wrote: >This particular point is not a matter of opinion. Package specs. and >abstract/deferred classes are simply and objectively different things. Actually, they seem pretty similar to me. They both define interfaces. Yes, there are various differences, but the unlerlying thing is that abstract_types=deferred_classes are pretty similar to package specs, in some interesting ways. That's an opinion, like it or not. >Read the Ada RM and then have another go at this. You will see that >the things are clearly different. Yes, they are somewhat different. (I had a hand in writing the Ada RM, and I know quite well how they're different!) But they still both have the same goal of defining an interface. I think Patrick's point is well taken: Why does Ada have both abstract types (which define an interface) and package specs (which define an interface)? I think there are good answers to that question, but merely saying, "well, abstract types are totally different from package specs (look at these details)" doesn't do it. - Bob