Re: Which book for ADA beginner ?

["Andrzej Lewandowski" <lewandoREMOVE@attglobal.net>]

"Brian Rogoff" <bpr@shell5.ba.best.com> 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.