Juergen Schoenwaelder wrote:
On Mon, Oct 16, 2006 at 12:06:38PM -0700, Andy Bierman wrote:IMO we want the simplest approach possible.Without specifying how you measure simplicity, your statement is rather pointless.This does not impact <filter type="xpath"> in PDUs. It is a simple canonical format for identifying ONE instance of an element. It is not intended to be some sort of filtering tool.A framework which allows to identify instances in some language X (and uses this language for say error reporting and access control) and has a required to implement a filter language which supports a filtering language Y where the expressive power of Y is a true subset of X seems a bit, lets say, surprising. Once again, I like X and I do believe Y will be overcome anyway if netconf is going to be successful. (So I better stop here since I believe the issue is pretty clear.)
We don't have 2 languages X and Y. We have a constrained algorithm for using Xpath to represent an Instance Identifier. I didn't think we needed to discuss all the functional requirements for an Instance Identifier, but let's try: - non-ambiguous, deterministic, canonical format - identifies a single instance in a static manner (Note that all filter expressions can yield different results based on when they are applied to the underlying datastore. We want an Instance ID to have 0 or 1 matches - An instance ID could be thought of as just an Xpath filter that selects a single instance, based solely on the data model naming components and element position.) - persistence: We would like an Instance ID 'match' at time T0 and later time T1 to represent the same conceptual instance. (Insert long debate about discontinuity markers here.)
/js
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