Re: The Foundation of OO (XDb)

From: James <jraustin1_at_hotmail.com>
Date: 13 Jun 2002 21:17:47 -0700
Message-ID: <a6e74506.0206132017.a55d808@posting.google.com>

> > An object (Marble) can have instances (M1, M2, M3).
> > An instance (M1) is an object that has a class (Marble).
> > A class (Marble) is an object that has an instance (M1).
>
> An object (Marble) can have objects (M1, M2, M3).
> An object (M1) is an object that has an object (Marble).
> An object (Marble) is an object that has an object (M1).
>
> Oh, yeah. That's useful!!!

After rethinking, I submit that substituting the word "object" for "class" and "instance" results in sentences that are not equivalent to the original. While classes and instances are objects, the word object does not encode the implied relationship to other objects that class and instance do.

I submit a parallel example, demonstrating the loss of information: Note: Assume John is a hermaphrodite.

A person(John) can have children (Mary, Sue).
A child (Mary) is a person that has a parent(John).
A parent(John) is a person that has a child (Mary).

A person(John) can have persons (Mary, Sue).

A person(Mary) is a person that has a person (John). A person(John) is a person that has a person (Mary).

Regardless, the exercise helped me to improve the definition of "my" object which I had already reposted in a new thread "OOPs! Object is the foundation of a Relation" Received on Thu Jun 13 2002 - 23:17:47 CDT