Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!know!samsung!dali.cs.montana.edu!uakari.primate.wisc.edu!aplcen!uunet!cimshop!davidm From: cimshop!davidm@uunet.UU.NET (David S. Masterson) Newsgroups: comp.object Subject: Re: The essence of objects... Message-ID: Date: 10 Jul 90 17:39:14 GMT References: <1280@media01.UUCP> Sender: davidm@cimshop.UUCP Distribution: comp Organization: Consilium Inc., Mountain View, California. Lines: 49 In-reply-to: pkr@media01.UUCP's message of 10 Jul 90 08:10:13 GMT In article <1280@media01.UUCP> pkr@media01.UUCP (Peter Kriens) writes: The essence of objects... ...is that they are objects. Sorry, I couldn't resist. However, this statement may actually be the focus of the rest of the article. But I still have problems explaining oops to people who have no prior experience. When I start talking about inheritance, dynamic binding they start to gaze and we both feel lost. Why is it so difficult to explain something which is so advantageous to use and which feels so right? How do I explain the essence of objects? Object orientation is "supposedly" an expression of problem modelling that is more *natural* to the way people think. I make no statement as to whether this is true or false. However, people's thought processes are their own, so perhaps the best way of explaining OOPS is to allow people to explain it to themselves. Lead them through a problem and see what manner they use to arrive at a solution, then equate that process to OOPS philosophy. When I think about it further it seems that I have never really seen a description about oops that touches the nucleus. There is a lot of talk about reuse, encapsulation, dynamic binding versus static binding, multiple inheritance versus single inheritance and many more "symptoms". But they seem to be the tools and not the essence. True. All the terms are for technical specialists to worry about. An "essence" may not be achievable because the "essence" of the problem is defined in the particular problem being solved at the moment. If this is the essence of oops, then I feel that we should focus on the specification of that functionality. How can we find those "functions" that fit in a world where they are only described once. Is your concern with "functionality" any more the essence of the problem than someone else's concern with the "information" involved with the problem. One is functional decomposition, the other is data definition, but are either the essence of object orientation? (Now for the tricky question) Are both? -- =================================================================== David Masterson Consilium, Inc. uunet!cimshop!davidm Mt. View, CA 94043 =================================================================== "If someone thinks they know what I said, then I didn't say it!"