> On 23 Aug 2016, at 10:25, Juergen Schoenwaelder > <[email protected]> wrote: > > On Tue, Aug 23, 2016 at 10:10:12AM +0200, Vladimir Vassilev wrote: >> On 08/23/2016 09:33 AM, Juergen Schoenwaelder wrote: >>> On Tue, Aug 23, 2016 at 08:42:34AM +0200, Vladimir Vassilev wrote: >>>> On 08/23/2016 12:08 AM, Alex Campbell wrote: >>>>> The intention in this case is obviously to evaluate the 'must' statement >>>>> if >>>>> the container contains any values; what would break if we said that >>>>> >>>>> A non-presence container exists in the data tree if and only if it has >>>>> any children which exist in the data tree. >>>>> >>>>> thus disallowing the existence of empty NP-containers in the data tree? >>>> The question is where is the misunderstanding. >>>> >>>> "If a node that exists in the accessible tree has a non-presence >>>> container as a child, then the non-presence container also exists in >>>> the tree." >>>> >>>> What does this mean? I believe there is confusion based on "the tree" >>>> refering not to the data tree but the Xpath context. At least I hoped until >>>> I realized the text was introduced as a solution to Y41 'clarification of >>>> "must" in NP-container'. That definitely means it addresses the must >>>> statements in the non-presence containers and it means "the tree" as in the >>>> data tree. >>> My reading is that 'tree' refers to the 'accessible tree' used earlier >>> in the sentence. The accessible tree itself is defined just above the >>> quoted sentence. If my reading of the text is correct, then the >>> obvious clarification would be: >>> >>> OLD >>> >>> If a node that exists in the accessible tree has a non-presence >>> container as a child, then the non-presence container also exists in >>> the tree. >>> >>> NEW >>> >>> If a node that exists in the accessible tree has a non-presence >>> container as a child, then the non-presence container also exists in >>> the accessible tree. >>> >>> /js >>> >> So should the must statements defined in the non-presence container which is >> now part of the accessible tree be evaluated or not? >> > > I think we need to carefully dissect things in order to make > progress. The above text is about XPATH contexts and accessible > trees. It is not about what needs to be checked during > validation. This is defined in section 8 and in particular section > 8.1. > > The following properties are true in a valid data tree: > > o All "must" constraints MUST evaluate to "true". > > This clearly talks about the data tree. The resolution of issue 42 > says: > > 2014-07-21 meeting proposal: Clarify that for validation purposes, > NP containers always exist. > > Putting these pieces together, it seems to me that for the purpose of > validation, an NP container is assumed to always exist in the data > tree and its MUST statement is evaluated.
But only if the closest ancestor that is not an NP-container exists, or there is no such ancestor. Lada > > /js > > -- > Juergen Schoenwaelder Jacobs University Bremen gGmbH > Phone: +49 421 200 3587 Campus Ring 1 | 28759 Bremen | Germany > Fax: +49 421 200 3103 <http://www.jacobs-university.de/> > > _______________________________________________ > netmod mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/netmod -- Ladislav Lhotka, CZ.NIC Labs PGP Key ID: E74E8C0C _______________________________________________ netmod mailing list [email protected] https://www.ietf.org/mailman/listinfo/netmod
