On Mon, Jun 28, 2021 at 11:54:04AM +0000, tom petch wrote: [...]
> As you say, this is never going to be an Erratum. Yep. > A leaf of type empty is encoded as, well, empty. > <voucher-type/> > as per RFC 7950. > > When this concept was first mentioned, my sense was that while it was > technically possible, it would still add complexity for little gain. As I > see YANG Doctors for ever saying, identity can be augmented, enumeration can > not so enumeration are used when you positively want to stop people > augmenting, when the concept does not make sense so a revised enum may make > sense or a change to something like identity which I see as as big a change > as the use of 'empty' but the latter is not in current use and so may cause > some uncertainty, some confusion. > Enumerations are centrally managed. Section 11 of RFC 7950 does allow additions to enums but only where the enum itself is defined, i.e., you need to create a new revision of the YANG module to add an enum value. An identity is more flexible as the value space is not centrally managed. Using leafs of type <empty/> as a way to define a non-centrally managed enumerated set of values really is a hack. It may work if people follow certain rules, but it is unlikely that tools will understand the rules (i.e., which places of a data model were designed to be used as a 'leafs of type <empty/> enumeration'). Hence, there is nothing that will prevents people from augmenting in a leaf that is not using the type empty or even an entire subtree of YANG definitions. I do not know exactly what the issue with RFC 8366 is but it seems you will have to revise the YANG module defined in RFC 8366 anyway. Note that there is also a middle ground, namely an enumeration type factored out into an IANA maintained module that is process wise easier to extend - should extensions be needed more regularly. /js -- Juergen Schoenwaelder Jacobs University Bremen gGmbH Phone: +49 421 200 3587 Campus Ring 1 | 28759 Bremen | Germany Fax: +49 421 200 3103 <https://www.jacobs-university.de/> _______________________________________________ Anima mailing list [email protected] https://www.ietf.org/mailman/listinfo/anima
