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NETCONF Data Modeling Language WG (netmod)
10th YANG 1.1 Virtual Interim
Wednesday, January 07, 2015, 16:00-18:00 CET
Minutes Juergen Schoenwaelder
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* Participants

  AB = Andy Bierman
  BC = Benoit Claise
  JS = Juergen Schoenwaelder
  DR = David Reid
  EV = Eric Voit
  IB = Ignas Bagdonas
  KW = Kent Watsen
  LL = Ladislav Lhotka

* Pending Actions

  - Y18 fix "when" expression context problem

    Pending action MB...

  - Y25 make enum numbering purely informative and optional

    JS to start a thread on the mailing list. There once was rough
    consensus for Y25-01 - we need to check what happens on the list.

  - Y57 non-unique leaf-list

    There was an action item for BL on 2014-10-15. Discuss today?

  - Y45 better conformance mechanism

    List of conformance use cases (action MB)

* Y07 do not allow when or if-feature on keys

  This issue is in the REVIEW state but there was quite some
  discussion on the mailing list. Where are we with this one?
  
  LL: It was legal to have if-feature on a key in YANG 1.0, even though
      it may not be too useful.
  AB: Since YANG 1.0 does not have optional keys, the server is going
      to reject this unless the expressions do match the parent (in
      which case the if-feature or when statement is redundant but
      not harmful).
  AB: The only valid if-feature/when must be redundant.
  JS: Should we add text to the guidelines about this so that tools
      are encouraged to flag this?
  AB: I agree.
  
  JS to followup on the mailing list thread, trying to summarize what
  was discussed today and to force a resolution of this issue.

* Y59 restrict use of 64-bit numbers in XPath expressions

  Moved to open, quite some discussion recently on the mailing list.
  Where are we with this one?
  
  LL: I updated the text in the issues file just a few minutes
      before the meeting.
  JS: This is SVN revision 104.
  AB: The text is fine.
  
  Proposal: Adopt Y59-01

* Y45 better conformance mechanism

  How to resolve this? Do we need to collect the requirements a
  solution must satisfy? It sometimes feels like going in circles on
  this.
  
  Skipped since MB was not joining the meeting.

* AOB
    
  LL: What about a structure statement as part of YANG 1.1?
  KW: May not work since RESTCONF won't wait for YANG 1.1.
  LL: It may be OK to use it in RESTCONF as an extension but there
      should be an 'official' solution.
  AB: It is not a step forward to use three different schema languages
      (YANG, XSD, something for JSON) in RESTCONF.
  JS: What is the benefit of having this extension rolled into YANG 1.1?
  JS: We should encourage using YANG extensions where possible. If a
      "structure" YANG extension that works with YANG 1.0 and 1.1 can
      be written today, then I do not see an urgent need to make this
      part of YANG itself.
  
  A team of people (AB, KW, MB?, LL?) will produce an initial I-D
  defining such a YANG extension. Once such an I-D is available, JS
  will work with the NETCONF chairs and Benoit Claise to (a) determine
  whether there is support for this approach in the community and to
  (b) determine how this can be best handled process wise (that is
  which of the two WGs can host this work).