On Fri, Nov 23, 2018 at 5:37 AM Robert Wilton <rwil...@cisco.com> wrote:
> > On 23/11/2018 13:29, Ladislav Lhotka wrote: > > On Fri, 2018-11-23 at 13:39 +0100, Juergen Schoenwaelder wrote: > >> On Fri, Nov 23, 2018 at 01:02:03PM +0100, Ladislav Lhotka wrote: > >>>> Here is an attempt to rewrite things in a way according to how I > >>>> understand things works. It should be possible to describe what we > >>>> mean. If we can't do that, we have a bigger problem. (I have changed > >>>> only the last two sentences.) > >>>> > >>>> OLD > >>>> > >>>> The leafref built-in type is restricted to the value space of some > >>>> leaf or leaf-list node in the schema tree and optionally further > >>>> restricted by corresponding instance nodes in the data tree. The > >>>> "path" substatement (Section 9.9.2) is used to identify the > referred > >>>> leaf or leaf-list node in the schema tree. The value space of the > >>>> referring node is the value space of the referred node. > >>>> > >>>> NEW > >>>> > >>>> The leafref built-in type is restricted to the value space of some > >>>> leaf or leaf-list node in the schema tree and optionally further > >>>> restricted by corresponding instance nodes in the data tree. The > >>>> "path" substatement (Section 9.9.2) is used to identify a leaf or > >>>> leaf-list node in the data tree. The value space of the leafref > >>>> node is determined by the value space of the schema tree node > >>> The term "value space of a schema tree node" is not defined. > >> OK. So we say 'the value space of the type of the schema tree node'. > > Yes, this is better. But what if the schema tree node is made invalid > due to a > > failed "when" expression? Does it still apply? > > I might be being picky, but it isn't absolutely clear from the text > which node "schema tree node" refers to. > > Hence I wonder whether it might be better to say "...identify the > referenced leaf or leaflist ..." and "value space of the referenced > schema tree node". > > IMO the RFC has a lot of room for improvement in this area: - the term "data node" is never defined but used 47 times - the term "data node identifier" is not defined or used - the term "schema node identifier" is defined and used 14 times (defined in sec. 3 Terminology and again in sec. 6.5) - every statement that uses some sort of path identifier (e.g. 9.9.2) needs to clearly specify whether the syntax is based on schema-node identifier or data-node identifier > Thanks, > Rob > > Andy > > > > >> > >>>> definining the referenced data tree node. > >>> With require-instance=false there needn't be any referenced data tree > node. > >> So we add "(irrespective whether the node exists or not). > > If the data tree node doesn't exist, we cannot refer to the schema tree > node > > that defines it. > > > >>>> This likely is not perfect yet but perhaps we manage to make it > >>>> perfect. ;-) What is not yet clearly described I think is what > >>>> 'further restricted by corresponding instance nodes in the data tree' > >>>> means (and that I think depends on require-instance). Perhaps add > >>> Right. In this case it is not "further restricted" but rather there is > a > >>> discrete set of possible values. > >> A discrete set of possible values is a restriction so I do not > >> understand your comment. So here is the next iteration: > > If required-instance is true, there is no need to care about all this > tricky > > stuff with schema tree nodes and their types. In other words: > > > > 1. if required-instance = true, the permitted values are obtained from > the data > > tree. > > > > 2. if required-instance = false, the corresponding schema node has to be > > determined, and its type defines the permitted values of the leafref > node. > > > > It is an exclusive-or, #1 is not an "optional further restriction". > > > > Lada > > > >> NEW: > >> > >> The leafref built-in type is restricted to the value space of some > >> leaf or leaf-list node in the schema tree and optionally further > >> restricted by corresponding instance nodes in the data tree (see > >> Section 9.9.3). The "path" substatement (Section 9.9.2) is used > >> to identify a leaf or leaf-list node in the data tree. The value > >> space of the leafref node is determined by the value space of the > >> type of the schema tree node definining the referenced data tree > >> node (irrespective whether the referenced data tree node exists or > >> not). > >> > >> /js > >> > > _______________________________________________ > netmod mailing list > netmod@ietf.org > https://www.ietf.org/mailman/listinfo/netmod >
_______________________________________________ netmod mailing list netmod@ietf.org https://www.ietf.org/mailman/listinfo/netmod
