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: 103376,3d3f20d31be1c33a X-Google-Attributes: gid103376,public X-Google-Thread: f43e6,2c6139ce13be9980 X-Google-Attributes: gidf43e6,public From: doylep@ecf.toronto.edu (Patrick Doyle) Subject: Re: Separation of IF and Imp: process issue? Date: 1997/09/01 Message-ID: #1/1 X-Deja-AN: 269339850 Sender: news@ecf.toronto.edu (News Administrator) References: <33E9ADE9.4709@flash.net> X-Nntp-Posting-Host: skule.ecf Organization: University of Toronto, Engineering Computing Facility Newsgroups: comp.object,comp.software-eng,comp.lang.ada,comp.lang.eiffel Date: 1997-09-01T00:00:00+00:00 List-Id: In article , Simon Wright wrote: >doylep@ecf.toronto.edu (Patrick Doyle) writes: > >> IMO, having separate interface and implementation files for the >> same package simply reinforces the somewhat antiquated notion >> that an implementation has only one interface. In fact, by >> Ada, they must have a one-to-one correspondence. > >[...] > >I don't quite know what you mean by "the somewhat antiquated notion >that an implementation has only one interface". The Java notion, >perhaps? I agree that this is a very interesting concept, not sure how >it maps onto Ada. What I mean is that a package in Ada has a single spec file. Thus, the implementation has a single interface. In Java or Eiffel, a single class can fulfill many different interfaces. In fact, Java's method isn't truly a several-interfaces approach because even though a class can implement several Java Interfaces, its overall interface can be expressed as the union of the individual interfaces. However, in Eiffel, a class can reveal different features to different clients, and thus actually have different interfaces. -PD -- -- Patrick Doyle doylep@ecf.utoronto.ca