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-Thread: 103376,5c89acd494ea9116 X-Google-Attributes: gid103376,public,usenet X-Google-Language: ENGLISH,ASCII Path: g2news2.google.com!news4.google.com!feeder1-2.proxad.net!proxad.net!feeder1-1.proxad.net!feeder.news-service.com!border-1.ams.xsnews.nl!feed.xsnews.nl!border-1.ams.xsnews.nl!ramfeed.eweka.nl!eweka.nl!lightspeed.eweka.nl!npeer.de.kpn-eurorings.net!npeer1.kpn.DE!newsfeed.arcor.de!newsspool1.arcor-online.net!news.arcor.de.POSTED!not-for-mail From: "Dmitry A. Kazakov" Subject: Re: Self pointer in limited record Newsgroups: comp.lang.ada User-Agent: 40tude_Dialog/2.0.15.1 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit Reply-To: mailbox@dmitry-kazakov.de Organization: cbb software GmbH References: <1183577468.034566.57830@n60g2000hse.googlegroups.com> <1188578849.187422.280620@50g2000hsm.googlegroups.com> <9fy1xoukz1e3$.h574sqmiauri$.dlg@40tude.net> <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> Date: Mon, 3 Sep 2007 21:17:59 +0200 Message-ID: <1mbajw59c3eir.jyl8bdp6qvj8.dlg@40tude.net> NNTP-Posting-Date: 03 Sep 2007 21:17:34 CEST NNTP-Posting-Host: 5d24cc5a.newsspool3.arcor-online.net X-Trace: DXC=3BlQc8[L2<^cHPTNZh_e7QMcF=Q^Z^V3X4Fo<]lROoRQ^;5]aA^R6>R76HPZhYVlLY[6LHn;2LCV^[bS8^ X-Complaints-To: usenet-abuse@arcor.de Xref: g2news2.google.com comp.lang.ada:1713 Date: 2007-09-03T21:17:34+02:00 List-Id: On Mon, 03 Sep 2007 17:55:33 +0200, Jean-Pierre Rosen wrote: > Dmitry A. Kazakov a �crit : >> It is difficult to see how an abstract state machine is not a type. The >> very word abstract assumes generalization, reuse and instances. It is types >> and generics, the tools to express the idea of instances. >> > Sorry, but I beg to disagree here. > > Abstraction is about the reduction of a real world objet to those > elements that are relevant for a given point of view. Of just one object? I think that an abstraction always apply to a set of things. What could be an abstraction of Spike, the dog? > A singleton is an abstraction of a single object, and does not need a > type. I don't see anything in the word abstract that assumes generalization. There is little abstraction in being alone. This is actually the reason why no type is need for a singleton: no abstraction, no instances, no type. In my view an abstract state machine has nothing to do with singletons. A state machine might be a singleton, per chance. But an *abstract* state machine is definitely a type that generalizes many concrete state machines. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de