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From: brucec@demiurge.WV.TEK.COM (Bruce Cohen;685-2439;61-028)
Newsgroups: comp.lang.c++
Subject: Re: OO Design books
Keywords: OOP, OOD, books
Message-ID: <4557@orca.WV.TEK.COM>
Date: 14 Sep 89 23:45:56 GMT
References: <583@calmasd.Prime.COM>
Sender: nobody@orca.WV.TEK.COM
Reply-To: brucec@demiurge.WV.TEK.COM (Bruce Cohen)
Organization: Tektronix, Inc., Wilsonville, OR
Lines: 38

In article <583@calmasd.Prime.COM> wlp@calmasd.Prime.COM (Walter Peterson) writes:
>In previous postings I have taken some people to task for the object
>models that they have presented on the net and I believe that the main
>reason for these poor models has been a lack of understanding of the
>general principles of OOD and excessive concentration on the mechanics
>of a particular language.

There is also a regrettable tendency even among the well-informed to be
careless in their use of OO terminalology (even when the proponents of
different languages agree on the meaning of the terms).  I find a classic
(pun intended) example of this just today in the Lippman book.  I could not
remember how to mix member initializations with arguments to superclass
constructors in a constructor definition, and I spent fifteen minutes
finding the right section in the book, because the title of the section is
"Class Initialization", which I took to mean initializing a class's
classvars, not the initialization of instances of a class.

Now, as you can see from *my* terminology, I learned Smalltalk as a first
OOL, and I tend to hark back to it.  I find that I have to sometimes,
because C++ terminology is either impoverished (I'd much rather say
"superclass", than "immediately ancestral base class"), or the meaning of
terms is fuzzy from ambiguous use (many people use "object" and "class"
interchangeably to mean "instance of class object").

Be clear that I'm not picking on Lippman; his book is my standard reference
for the syntax and semantics of C++, and has been since the day I got it.
I am saying that there is a body of theory and practice in OO languages,
systems, and programming, and that much of that existed before C++, and is
applicable to C++.  Not applying it means that distinctions not clearly
made by the programming language are not clear to the designer/programmer,
who has no other abstractions to use in thinking about these areas.  This
makes such areas a source of loss of expressiveness and design options, and
potentially even a source of error in programming.

Bruce Cohen
brucec@orca.wv.tek.com
Interactive Technologies Division, Tektronix, Inc.
M/S 61-028, P.O. Box 1000, Wilsonville, OR  97070