Re: Interesting but sensitive topic to discuss (HELP: - OOP and CASE t

[piercarl@sabi.demon.co.uk (Piercarlo Grandi)]

Alan Lovejoy writes:

> OO programs are systems of interacting **objects**, not systems of
> interacting **classes**.

ok> jhd@herold.franken.de (Joachim Durchholz) writes:

jhd> I think this is a bit misleading.  OO program texts are definitely
jhd> systems of classes (or, rather, textual representations of
jhd> classes).

>>> "ok" == Richard A O'Keefe <ok@goanna.cs.rmit.edu.au> writes:

ok> This is an overgeneralisaton.  Not every OO language is class
ok> based. [ ... consider Self etc ... ]

Well, but then they something like prototype based, as you observe.

The observation above is, as per your remark, strictly speaking not
general enough; but then just saying "OO module" instead of "class"
would give it generality.

For whether class or prototype based, an OO program is a collection of
(OO) modules, and values at runtime are either instances of a class or
clones of a prototype.

OO programs (as opposed to their executions) do occasionally contain
some instances or clones, but this does not justify the observation that
"OO programs are systems of interacting **objects**".

While the analysis and design of an OO program may/should be based on
some mental image of how it is going to be executed, both activities are
really about deciding into which ``encapsulated'' concepts and modules
to decompose the solution to a problem, and not into which
``interacting'' objects (even if in some languages OO modules are
objects, and in some others objects to interact).