Ladislav Lhotka <[email protected]> wrote: > > > On 23 Nov 2015, at 13:19, Martin Bjorklund <[email protected]> wrote: > > > > Hi, > > > > derived-from is defined as: > > > > boolean derived-from(node-set nodes, > > string module-name, > > string identity-name) > > > > The derived-from() function returns true if the first node in > > document order in the argument "nodes" is a node of type > > identityref, and its value is an identity that is derived from the > > identity "identity-name" defined in the YANG module "module-name"; > > otherwise it returns false. > > > > > > The "first node in the node set" doesn't work well with leaf lists. I > > suggest this change: > > > > NEW: > > > > The derived-from() function returns true if any node in > > the argument "nodes" is a node of type > > identityref, and its value is an identity that is derived from the > > identity "identity-name" defined in the YANG module "module-name"; > > otherwise it returns false. > > This makes sense.
Good. > In fact, other XPath functions (deref() and > enum-value()) are also defined using "the first node in document > order". This seems to be at odds with sec. 6.4 that says: "This means > that XPath expressions in YANG modules SHOULD not rely on any specific > document order." Is it OK that the result of such functions is > undefined if the node-set argument contains multiple nodes? I think so. These functions are intended for single leafs (what is the enum value of a leaf-list?). The alternative would be to say that it is an error if the node set contains more than one node, but XPath functions rarely returns errors. /martin _______________________________________________ netmod mailing list [email protected] https://www.ietf.org/mailman/listinfo/netmod
