Re: Oracle8's new features - what are they

From: Drew Wade <drew_at_objy.com.junk>
Date: 1997/06/03
Message-ID: <AFB8D77F9668453637@sjx-ca73-02.ix.netcom.com>#1/1

In article <Pine.NEB.3.95.970531134612.28728A-100000_at_cripplecock.sarc.city, Akmal B Chaudhri <akmal_at_no_spam.uk> wrote:

>Drew, I don't want to seem argumentative, but what definitions are you
>using here? Free floating procedures can provide encapsulation by having a
>well-defined interface to hide the implementation details. Having them
>associated with a particular class is another matter. Here the definition
>of encapsulation is referring to the ability to have a well-defined
>interface and hide implementation details - something which non-OO
>languages, such as C or Pascal can also provide. If this is supported in
>Oracle and SQL3, etc., then it does support encapsulation, albeit not in
>the OO-sense (i.e. not having a "method" associated with a particular
>class).

ok, i agree. in principal, one could define encapsulation independent of classes or types. in practice, the object technology community has converged on a type based model. but you're correct, akmal, the important point is to hide the internals. i don't believe the oracle 8 approach does that (as explained by other posters here...i don't claim oracle expertise, just correcting the o.t. terminology).

now, i don't agree that c or pascal have encapsulation. they have no explicit support for defining an external interface that is separate from and hides the internals. (well, pascal has some...). i don't agree that such languages are properly said to support encapsulation or to be object languages.

this is not to say that you could not do o.t. programming in c (or assembly language, for that matter). o.t. is a style that could be used with any (or no) tools. but an object language should provide techniques to support the concepts of types (and polymorphism), subtypes (and inheritance), and of course encapsulation (and abstraction).

academically speaking, there are kinds of other possibilies; e.g., self, from stanford, is a type-less language with all the other object concepts, but, effectively, a single instance for every type (or equivalently, no types at all). and these can be fruitful to explore, to expand our knowledge. but in practice, the meaning of o.t. has pretty much settle down.

regards,
drew

Drew Wade                      mailto:drew_at_objy.com
Objectivity, Inc.              mailto:info_at_objy.com
301B E. Evelyn Avenue          http://www.objy.com/

Mountain View, CA 94041-1530 +1 (415) 254-7113, 71 fax Received on Tue Jun 03 1997 - 00:00:00 CDT