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: 103376,9982360189bfe852 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-01-28 17:34:34 PST Reply-To: "Andrzej Lewandowski" From: "Andrzej Lewandowski" Newsgroups: comp.lang.ada References: <3A71400E.32057C6B@becker.k.pl> <3a72224b_2@news3.prserv.net> Subject: Re: Which book for ADA beginner ? Date: Sun, 28 Jan 2001 20:28:14 -0600 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 NNTP-Posting-Host: 32.100.225.253 Message-ID: <3a74c829_2@news3.prserv.net> X-Trace: 29 Jan 2001 01:32:25 GMT, 32.100.225.253 Organization: Global Network Services - Remote Access Mail & News Services X-Complaints-To: abuse@prserv.net Path: supernews.google.com!sn-xit-02!supernews.com!nntp-relay.ihug.net!ihug.co.nz!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!logbridge.uoregon.edu!newsfeed.us.ibm.net!ibm.net!news3.prserv.net!32.100.225.253 Xref: supernews.google.com comp.lang.ada:4640 Date: 2001-01-28T20:28:14-06:00 List-Id: "Brian Rogoff" wrote in message news:Pine.BSF.4.21.0101281019400.7734-100000@shell5.ba.best.com... > I can't speak for Andrzej, but I did notice on perusing the programs at > the web site > > http://www.brighton.ac.uk/ada95/programs/home.htm > > that Smith tends to use packages as classes. I'm not disposed towards that > approach, but I'm also not disposed towards "OO uber-alles" in general so > take that however you want to. I don't think that tagged records make > variant records obsolete (yes JE, I wish you'd change your book :), so > I'd like Ada books to cover a few approaches. > Some people express the opinion that the necessary condition for a language to be OO is that this language has classes. These classes MUST be C++ style. Ada95 (and Oberon; it is interesting what was the impact of Oberon and Wirth's work on extensible types on Ada 95 design of tagged types, if any) has different mechanism. Moreover, it has been pointed out (see the book on component programming by Szyperski and his presentation on one of ECOOPs) that object orientation and modules are in principle orthoogonal concepts, and that BOTH and SEPARATE are required to build well structured OO programs. C++, Eiffel, Smalltalk ond others are using classes for both purposes: OO and encapsulation (say, modularization). Ada95 and Oberon are two (well, maybe not the ONLY two...) languages that separate these two notions. In other words, these languages are the only languages that make this RIGHT. Therefore, an attempt to emulate C++ classes in Ada95 just to have the same mechanisms as in C++ is not a prograss, it is a step backward. A.L.