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: 103376,3d3f20d31be1c33a X-Google-Attributes: gid103376,public X-Google-Thread: 1108a1,2c6139ce13be9980 X-Google-Attributes: gid1108a1,public X-Google-Thread: f43e6,2c6139ce13be9980 X-Google-Attributes: gidf43e6,public From: Paul Johnson Subject: Re: Interface/Implementation (was Re: Design by Contract) Date: 1997/09/12 Message-ID: #1/1 X-Deja-AN: 272153981 Distribution: world X-NNTP-Posting-Host: treetop.demon.co.uk [158.152.55.135] References: <340F20A0.49B5@ac3i.dseg.ti.com> <340F39E3.4B71@pseserv3.fw.hac.com> <5v32se$l7u$1@miranda.gmrc.gecm.com> Organization: home Newsgroups: comp.object,comp.software-eng,comp.lang.ada,comp.lang.eiffel Date: 1997-09-12T00:00:00+00:00 List-Id: In article , Robert Dewar writes >Paul says > >>is an interesting possibility. Most organisations with configuration >>control have some kind of test or inspection procedure before release. >>Either of these would be sufficient to enforce the existing interface. >>Tests would fail with changed interfaces, and inspectors would reject >>changed interfaces precisely because they will break existing >>software. > >This misses the point. That is like saying, never mind we don't need CM >at all, because our integration testing will catch any errors. No, I don't think it does. >You cannot rely on test and inspection to catch errors. I agree that automated trapping of errors is better (its one of the reasons I like Eiffel). I just raised the possibility that in practice this particular catagory of error had not caused enough trouble to make someone implement it. The origin of this, if you recall, was that someone had wondered why nobody was doing this. >If lack of proper CM has allowed interfaces to wander, then who knows >what other resultant errors have been produced. Which is rather the point: does this lack of separate CM for interfaces and implementation actually cause that much trouble in practice? In another thread I was criticised for claiming that the theoretical foundation for Eiffel exception handling made it superior to Ada exception handling. Now I'm being criticised for not recognising separate interfaces as superior because they stem from another theory of software engineering. I agree that separate CM of interfaces is better, but I wonder if it makes enough difference to be worth while implementing. Paul. --------------------------------+--------------------------------- Paul Johnson | You are lost in a maze of twisty Email: Paul@treetop.demon.co.uk | little standards, all different. paul.johnson@gecm.com |