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Re: Some additional obscure questions...



HI Bob,

I think you are trying to change the point, which is that examples
to demonstrate conformance are more powerful when they check all
aspects of the conformance instead of the trivial case. Of course,
examples to "teach" about functionality would be written differently.
And examples to show common practice would be different.

On the forward reference issue....
First, forward references are a feature of ASN.1, and one that is
carried forward to the MIB module language. (And yes, supporting or
not supporting forward references makes a BIG difference in MIB
compiler design, including data structures and error detection
and reporting!)
Second, someone would have to do all the work to determine if
eliminating all forward references would create an undue hardship
on writing (and reading) MIB modules. There is one place (not in
the imports) that MIB compilers not supporting forward references 
results in pretty ugly MIB module specification. That is the OID
value that is used for the value of a MODULE-IDENTITY construct.

At 02:18 PM 2/3/2003 -0500, Bob Natale wrote:
>Hi Dave,
>
>>It is a "better example", not a better "coding convention". It is
>>a better example because it makes a forward reference to parentOfA.
>>A MIB compiler that didn't support forward references would
>>support the first example, but not the second. Thus, the second
>>example tells us more about the capabilities of the MIB compiler
>>than the first.
>
>Ok.  But if including the forward reference
>is not a better coding convention, why should
>a MIB compiler support it?
>
>IMHO:  One cannot reasonably say that writing
>the example below that avoids the fwd ref is
>more difficult than the one that avails itself
>of the fwd ref, so ease of use is not the reason.
>And, for conceivable examples where it might be
>"easier" to construct a MIB with such fwd refs
>(than building the supporting base beforehand),
>from the perspective of coherency of overall
>MIB design, it seems that fwd refs (1) are not
>necessary and (2) lead to design complexity
>(of the ugly kind) with ancillary negative
>impacts on other aspects of the overall mgmt
>infrastructure.
>
>So, why would you (the general "you") want to
>see fwd ref support in a MIB compiler?
>
>Thanks,
>
>BobN
>- - - - -
>>At 03:12 AM 1/31/2003 -0500, Bob Natale wrote:
>>>At 1/31/2003:12:50 AM, David T. Perkins wrote:
>>>
>>>Hi Dave,
>>>
>>>>> ...
>>>>>   AnotherModule DEFINITIONS ::=
>>>>>   BEGIN
>>>>>      IMPORTS
>>>>>         parentOfA FROM NON-AMBIGUOUS-MIB
>>>>>         a FROM M1 { parentOfA 1 }
>>>>>         a FROM M2 { parentOfA 2 }
>>>>       ...
>>>>    END
>>>>
>>>>or better yet...
>>>>   AnotherModule DEFINITIONS ::=
>>>>   BEGIN
>>>>      IMPORTS
>>>>         a FROM M1 { parentOfA 1 }  -- a forward reference
>>>>         a FROM M2 { parentOfA 2 }
>>>>         parentOfA FROM NON-AMBIGUOUS-MIB
>>>>       ...
>>>>   END
>>>
>>>Why do you consider the second form better
>>>than the first?
>>>
>>>Cheers,
>>>
>>>BobN 
>>Regards,
>>/david t. perkins 
Regards,
/david t. perkins