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=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,103b407e8b68350b X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-02-04 02:10:26 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!cyclone.bc.net!newspump.monmouth.com!newspeer.monmouth.com!newsfeed.icl.net!newsfeed.fjserv.net!colt.net!newsfeed.esat.net!feeder.news.heanet.ie!not-for-mail Newsgroups: comp.lang.ada From: Colin_Paul_Gloster@ACM.org (Colin Paul Gloster) Subject: Re: Anybody in US using ADA ? One silly idea.. References: <1043880843.44251@master.nyc.kbcfp.com> <1043938782.244443@master.nyc.kbcfp.com> <25ji3v8n915cnnnaqpjvm4f7i01a66r9pf@4ax.com> <1043949507.331484@master.nyc.kbcfp.com> <1044025336.3067@master.nyc.kbcfp.com> <1044033063.693737@master.nyc.kbcfp.com> <2b9s3vo3bbnaikqd6d4jpppfflfq2kbgfu@4ax.com> <1044278793.419261@master.nyc.kbcfp.com> Reply-To: Colin_Paul_Gloster@ACM.org Message-ID: User-Agent: slrn/0.9.7.0 (SunOS) Organization: Dublin City University (DCU) Cache-Post-Path: ns2-ext.dcu.ie!unknown@camac.dcu.ie X-Cache: nntpcache 2.3.3 (see http://www.nntpcache.org/) Date: 04 Feb 2003 10:10:25 GMT NNTP-Posting-Date: 04 Feb 2003 10:10:25 GMT NNTP-Posting-Host: 136.206.1.1 X-Trace: 1044353425 reader.news.heanet.ie 61617 [::ffff:136.206.1.1]:34959 Xref: archiver1.google.com comp.lang.ada:33752 Date: 2003-02-04T10:10:25+00:00 List-Id: Timestamped Mon, 03 Feb 2003 10:59:39 +0100, news:2b9s3vo3bbnaikqd6d4jpppfflfq2kbgfu@4ax.com by Dmitry A. Kazakov contains: "On Fri, 31 Jan 2003 12:11:03 -0500, Hyman Rosen wrote: [..] >[..] You claim that there is benefit >in requiring that types support unused operations. I >don't see what that benefit is, or where you cut off >the infinite list of possible operations that a type >could conceivably support. If you define a type, say, "field". Then you should implement all operations of the field." Yes. "Otherwise, it is not a field, but a group or something else." Yes. "So the users of your type would have no delusions about it. If it has interface of a group, why to present it as field?" Indeed. And why if it has operations you do not need, are you defining this type and using it? "It is just DbC. Ada gives an example of this approach: when you derive from an abstract type, the derived non-abstract type has to implement all abstract operations, no matter whether some of them will never be used. Failure to do that is a *compile-time* error. Same thing with C++ templates produces a "valid" program! (Ada generics are safer in this respect)" Having unused procedures (of unknown quality) is not safe. Timestamped Mon, 03 Feb 2003 17:12:24 +0100, news:lats3vchsfmpaqiid539c8l7q0293eelcf@4ax.com by Dmitry A. Kazakov has: "On Mon, 03 Feb 2003 08:26:33 -0500, Hyman Rosen wrote: [..] >You then >claim that this implicit interface needs to be augmented >with operations that the procedure doesn't need, and then >that types upon which the procedure operates need to have >these useless operations, and that this somehow achieves >safety! I am just baffled. They are not useless, they constitute the type. [..]" There are not used therefore they are useless.