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=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,5c89acd494ea9116 X-Google-Attributes: gid103376,public,usenet X-Google-Language: ENGLISH,ASCII Path: g2news2.google.com!news3.google.com!feeder1-2.proxad.net!proxad.net!feeder1-1.proxad.net!oleane.net!oleane!hunter.axlog.fr!nobody From: Jean-Pierre Rosen Newsgroups: comp.lang.ada Subject: Re: Self pointer in limited record Date: Thu, 06 Sep 2007 09:19:54 +0200 Organization: Adalog Message-ID: <0n9obf.tgd.ln@hunter.axlog.fr> References: <1183577468.034566.57830@n60g2000hse.googlegroups.com> <46d968ee$0$30368$9b4e6d93@newsspool4.arcor-online.net> <137iu0lr82dtb$.wqy3zjz2vr9q.dlg@40tude.net> <46d972e8$0$30384$9b4e6d93@newsspool4.arcor-online.net> <1alyfwaig93sk$.99oy269uon$.dlg@40tude.net> <46d9c138$0$4531$9b4e6d93@newsspool3.arcor-online.net> <1rt8kdcrj6tf.1qgvycc6vh357$.dlg@40tude.net> <46db2bf4$0$7699$9b4e6d93@newsspool2.arcor-online.net> <1188816674.2630.25.camel@kartoffel.vocalweb.de> <9cdmw7k85sey.85sb2t1bjefy$.dlg@40tude.net> <1mbajw59c3eir.jyl8bdp6qvj8.dlg@40tude.net> <1188850449.2630.60.camel@kartoffel.vocalweb.de> <1aza6nzawgcnm.sf76q4dvzw4n$.dlg@40tude.net> <46de8897$0$16115$9b4e6d93@newsspool1.arcor-online.net> <15hzyyy3soem0.12hn79bwy27zt$.dlg@40tude.net> <36wdoqy402nv$.14ugvmc6edxwu.dlg@40tude.net> <128w4o7mesap4$.jjwa555mydo6$.dlg@40tude.net> NNTP-Posting-Host: mailhost.axlog.fr Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Trace: s1.news.oleane.net 1189065673 18517 195.25.228.57 (6 Sep 2007 08:01:13 GMT) X-Complaints-To: abuse@oleane.net NNTP-Posting-Date: Thu, 6 Sep 2007 08:01:13 +0000 (UTC) User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) In-Reply-To: <128w4o7mesap4$.jjwa555mydo6$.dlg@40tude.net> Xref: g2news2.google.com comp.lang.ada:1778 Date: 2007-09-06T09:19:54+02:00 List-Id: Dmitry A. Kazakov a �crit : >> 2 certainly can. The idea is that you cannot put "Spike the dog" into >> your computer; what you can do is put some characteristics of it in the >> form of data that are of interest from the point of view of your >> program. You therefore abstract away all the uninteresting properties. > > Yes, but my point is that these characteristics would have qualitative or > quantitative values from some sets. For example weight. Can I change it? > Would it be Spike? If yes, then what does the weight characterize? Of course, if I feed Spike too much, its weight will change - and it is still Spike. I don't see the problem here. > If not, > where is Spike? As long as I can construct (not Spike), it is not unique. But if, *for my problem*, I am interested only in Spike, (not Spike) makes no sense. I'm not arguing that there cannot be a class of dogs, but that if in my problem domain I am interested in the properties of a single object, I can represent that single object in a computer, and that the representation of this single object, because it omits all the details that are not relevant to my problem, is an *abstraction*. >> How could you have something in the model that is not in what you are >> modelling? > > I can add some properties to make implementation simpler or possible. Ha! You said "implementation". To me, that's the concrete view. The abstract view is there to hide implementation details. -- --------------------------------------------------------- J-P. Rosen (rosen@adalog.fr) Visit Adalog's web site at http://www.adalog.fr