Re: Methods in the NIM requirements

["John Strassner" <jstrassn@cisco.com>]

Walter,

I think that you are struggling because you continue to try
and pry apart attributes and methods, when both are needed
to properly define an object. I would encourage you to
reread the multiple responses from this list that agree with
that. For your convenience, here is a textbook definition of
an object:

  "An object class describes a group of objects
   with similar properties (attributes), common
   behavior (operations), common relationships
   to other objects, and common semantics."

Thus, your basic assumption of "...a class is defined with a
set of attributes that can be manipulated to affect
particular changes in the system that the object is meant to
model" is wrong. Furthermore, it is scary to think that just
by setting an attribute, all of the proper semantics that
are necessary to properly define object behavior magically
happen. It is equally scary to think that by setting
multiple attributes that collectively define a configuration
change, the same auto-magical behavior happens (not to
mention how the attributes were synchronized in the first
place).

Finally, your statement "...the method is the interface to
the object (and therefore the system)" is in general far too
limiting. Methods are defined as PART of an object
interface, not THE interface(s) of an object.

regards,
John
----- Original Message -----
From: "Weiss, Walter" <WWeiss@lucentctc.com>
To: <nim@ops.ietf.org>
Sent: Tuesday, April 18, 2000 12:56 AM
Subject: Methods in the NIM requirements


> I am really struggling with this thread. Here is my basic
problem. In many
> of the models I have seen (including some I have worked
on), a class is
> defined with a set of attributes that can be manipulated
to affect
> particular changes in the system that the object is meant
to model. Hence,
> the set of attributes provide an interface to the system
being described. In
> contrast, traditional OO design approaches suggest that an
object has a set
> of attributes that are not directly accessable except with
the use of
> methods. Hence, the method is the interface to the object
(and therefore the
> system). If we want to incorporate methods in the NIM
requirements, then the
> methods should represent the primary interface, obviating
the need for most
> attributes (except as parameter definitons for the
methods).
>
> regards,
>
> -Walter
>
>
>