Re: Some additional obscure questions...

[Bob Natale <Bob.Natale@AppliedSNMP.com>]

At 2/6/2003:01:22 PM, Randy Presuhn wrote:

Hi Randy,

I appreciate your input on this thread.  I hope
that my response below will help to carry the
dialogue forward towards a better understanding
of how the concept of "forward reference" *might*
not yet be precisely defined/used in discussions
of the SMI.

>> So, why would you (the general "you") want to
>> see fwd ref support in a MIB compiler?
>
>One case where forward references may be
>unavoidable is the case of DEFVALs referencing
>OBJECT-TYPEs.  A contrived example:
>
>a OBJECT-TYPE ... DEFVAL { b } ...
>b OBJECT-TYPE ... DEFVAL { a } ...

Let's see:  I interpret that as really meaning:

desc_a OBJECT_TYPE...SYNTAX OID...DEFVAL { name_b }
desc_b OBJECT_TYPE...(nothing else about this object
                      matters for the example)

...where "desc_x" is the human-readable descriptor
and "name_x" is the OID value of the object.

I'm not sure I've got the right terminology at
hand here to explain my take on this, but as I
said in an earlier response, I don't think that
using an OID as a *value* in a MIB counts as a
"forward reference" in the context of this thread.

That is, the possible value for any DEFVAL clause
of any OBJECT-TYPE definition is any value from
the set of legal values according to the SYNTAX
clause of that definition.  Since the SYNTAX
clause defines the set (of values), the designation
of any value among that set is not a "forward
reference".

In my view, the meaning of "forward reference"
that is central to this discussion refers to a
specification in the naming hierarchy of the MIB
that is not rooted in the predecessor  portion
of the MIB (modulo de jure standard starting
points).  (Note that the use of "the MIB",
rather than "a MIB" is deliberate there.)

Since you are extremely accomplished in this
set of concepts, I am hoping that you can provide
both the correct terminology and the correct
understanding.

Cheers,

BobN