RE: Closing on NIM requirements

["Andrea Westerinen" <andreawest@mindspring.com>]

Totally agree but we need the right data, relationships AND methods.  IMHO,
a tire may be modeled with:
- an enumeration indicating composition (perhaps to understand lifetime and
traction)
- an integer indicating CurrentPressure (to understand if it is flat or not)
- a gauge of RotationsPerMinute to guarantee that legal speeds are not
exceeded
- a relationship to other objects like the hub/axle to which it is attached,
or if not important the car to which the ticket is issued when legal speeds
are exceeded
- a method like "uint32 Refill([INPUT] AmountOfPressure)" when tires are
high availability items that can be refilled based on road conditions and
policy

Perhaps on most objects, there aren't any methods.  However, I would caution
against throwing out an important modeling tool, under the auspices of being
"declarative".  In my mind, an object oriented design is just as
"declarative" as a list of properties.

Andrea

> -----Original Message-----
> From: owner-nim@ops.ietf.org [mailto:owner-nim@ops.ietf.org]On Behalf Of
> Harald Tveit Alvestrand
> Sent: Monday, April 17, 2000 10:30 PM
> To: Durham, David; 'John Strassner'; 'Weiss, Walter'; nim@ops.ietf.org
> Subject: RE: Closing on NIM requirements
>
>
> At 19:22 17.04.2000 -0700, Durham, David wrote:
> >Yes, I see the importance of methods, but where to start and
> where to stop?
> >I would like to start with the definition of data. Next, move
> this strictly
> >declarative model into a functional model:
> >
> >Describe wheels: Round, rubber, etc.
>
> .....
>
> >Describe wheel operations: Turn(), StopTurning(), etc.
> but the rubberness of the wheel has no interest if the property we're
> looking to model is the RotationsPerMinute property....and the network
> model probably needs no representation of the thickness of a
> router's chassis.
>
> modelling is also the art of throwing away information not
> relevant to the
> model's purpose.
>
>                   Harald
>
> --
> Harald Tveit Alvestrand, EDB Maxware, Norway
> Harald.Alvestrand@edb.maxware.no
>
>