Ladislav Lhotka <[email protected]> wrote: > > > On 10 Sep 2015, at 12:55, Martin Bjorklund <[email protected]> wrote: > > > > Hi, > > > > I think we agreed that is ok for a YANG 1.1 module to import a YANG > > 1.0 module. > > > > But should it also be ok for a 1.0 module to import a 1.1 module? > > I think it should be illegal for a 1.0 module to import with revision > if the requested revision is 1.1.
Ok. > > If we make this illegal, we might run into problems. For example, > > ietf-ip imports ietf-interfaces. Suppose we update ietf-interfaces > > and the new version use YANG 1.1. Is it ok for a server to implement > > the 1.0 version of ietf-ip and 1.1 version of ietf-interfaces? If the > > answer is no, it means that we either have to update all modules to > > 1.1 more or less at the same time (including vendor models!), or we > > keep existing modules on 1.0 "forever". > > > > At the lastest interim, it was suggested that a server that implements > > such a combination of models would internally promote the 1.0 module > > to 1.1, and thus make this combination legal. > > I think we need a way for the server to identify itself to the client > as 1.1-capable, and then: > > - 1.1-capable server: if 1.0 module X imports Y *without revision*, and > the revision of Y advertised by the server (with > default-revision=true), then module X is automatically interpreted as > 1.1. I assume you mean that Y is 1.1. > - 1.0-only server: if 1.0 module X import Y without revision, then the > latest 1.0 revision of Y is used. If 1.1 revisions exist, they are not > used. Yes. > > Such a strategy should also be safe for old clients, still treating > > the module as being 1.0. > > I am not sure about this, I think a 1.0-only client cannot work with a > 1.1-capable server is some 1.1 additions are used (e.g. if-feature > expressions). Note that the 1.0 client worked with the 1.0 server with 1.0 modules X and Y before. Now Y is updated to 1.1. According to section 10, Y is not allowed to add if-feature to existing definitions. /martin > > It is a bit unclear what the server should do if the 1.0 module that > > it "internally promotes" to 1.1 contains something that is illegal in > > 1.1, e.g.: > > > > default "a\xb”; > > We should write an erratum to 6020 making this illegal in 1.0, too. > > Lada > > > > > Comments? > > > > > > /martin > > > > _______________________________________________ > > 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
