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,b87849933931bc93 X-Google-Attributes: gidfac41,public X-Google-Thread: 1108a1,b87849933931bc93 X-Google-Attributes: gid1108a1,public X-Google-Thread: 109fba,b87849933931bc93 X-Google-Attributes: gid109fba,public X-Google-Thread: 103376,b87849933931bc93 X-Google-Attributes: gid103376,public X-Google-Thread: f43e6,b87849933931bc93 X-Google-Attributes: gidf43e6,public X-Google-Thread: 114809,b87849933931bc93 X-Google-Attributes: gid114809,public From: jsa@alexandria (Jon S Anthony) Subject: Re: OO, C++, and something much better! Date: 1997/01/10 Message-ID: #1/1 X-Deja-AN: 209024115 sender: news@organon.com (news) references: organization: Organon Motives, Inc. newsgroups: comp.lang.c++,comp.lang.smalltalk,comp.lang.eiffel,comp.lang.ada,comp.object,comp.software-eng Date: 1997-01-10T00:00:00+00:00 List-Id: In article <32D536C6.64880EEB@eiffel.com> Bertrand Meyer writes: > Robert I. Eachus wrote: > > > > > > Bertrand Meyer said: > > > > > In my opinion neither Ada (83 or 95) nor C++ has the combination > > > of mechanisms making it possible to have the full power of > > > generics in an object-oriented language, as present in Eiffel... > > > > And then listed four properties, all of which are in Ada 95! > > I disagree. What Mr. Eachus showed in his message is ways to achieve > in Ada 95 the effect of the object-oriented mechanisms I described, > as implemented in Eiffel. And he is correct that one can use Ada 95 > to obtain many of the same goals. (This would not be true, for example, > of C++ and even less of Java.) But this does not mean the "four > properties" that I listed are in Ada 95. Anyone who checks my > message and the Ada 95 language definition will see that. I am willing to buy this - more or less - as I noted in my original reply. But, your original post (with the relevant part right up there just above) does not SAY this. It certainly _reads_ like you are saying that Ada 95 has none of these properties - and that is just plain outright indisputably FALSE. In fact, the _only_ one that it does not have at the level you suggest is the so called "completely consistent type system" which seems to really mean "an Eiffel style type system". The other three are there and actually are rather better done in Ada, IMO, than the equivalent Eiffel. > At some point, of course, one runs into matters of taste. I will > again contend, however, that a rational, systematic analysis of > O-O principles and how they combine with genericity, information hiding > and other software engineering concerns almost inevitably lead to the > Eiffel mechanism Well, the big problem here is that there are so many "loaded" terms in this without any universally accepted definitions and certainly no universally accepted _value_ judgements and absolutely no objective series of studies supporting anything one way or the other, that it just doesn't say anything more than: "In my reasoned view, Eiffel is better, and I have listed various reasons for my belief." Fair enough. But having done the above so called "rational, systematic analysis" of so called "O-O principles", I've arrived at rather a different conclusion and have listed reasons for this in the past as well. In particular, MI useage, in my perusals, is nearly universally conceptually confused. It is not a very good way of "modeling" things. It _can_ be a decent way of "code reuse" - but it is not worth the conceptual price given readily available alternatives. Shrug. /Jon -- Jon Anthony Organon Motives, Inc. Belmont, MA 02178 617.484.3383 jsa@organon.com