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Re: Gen-Art LC review: draft-ietf-netmod-yang-metadata-04

2016-03-11 11:17:22
I assume 'An annotation carries a single value.' should be clear
enough. A reference to section 7.6 is actually misleading since
that section deals with many more things that are not applicable
to leafs. But I think we are already done with this.

/js

On Fri, Mar 11, 2016 at 04:39:54PM +0000, tom p. wrote:
----- Original Message -----
From: "Juergen Schoenwaelder" 
<j(_dot_)schoenwaelder(_at_)jacobs-university(_dot_)de>
Sent: Friday, March 11, 2016 1:07 PM


On Fri, Mar 11, 2016 at 11:15:28AM +0000, tom p. wrote:
Lada, Robert

The other angle from which this might be approached is that the I-D
already says

"   Using the "type" statement, a type is specified for the
annotation
   value according to the same rules as for YANG "leaf" type. "

while rfc6020bis says

"   The "leaf" statement is used to define a scalar variable of a
   particular built-in or derived type."

so if you know your YANG off by heart, then you will know that
annotations must be scalar.  I agree that the text needs to be
clearer.
Perhaps,
OLD
"   o  annotations are scalar values and cannot be further
structured;"
NEW
"Annotations obey the same rules as for a YANG "leaf" type
[rfc6020bis
s.7.6] and so are limited to scalar variables."

There is no 'leaf type' in YANG. YANG has leaf nodes in the schema
tree. An annotation is not a node in the schema tree. Perhaps
something like this:

Juergen

Well, I know, but I was quoting directly from yang-metadata-04 s.3,
namely

"Using the "type" statement, a type is specified for the annotation
   value according to the same rules as for YANG "leaf" type. "

which is why I gave a reference to s7.6 of RFC6020bis rather than s.7.4.

Perhaps change s.3 in addition to your change

OLD
   Using the "type" statement, a type is specified for the annotation
   value according to the same rules as for YANG "leaf" type.
NEW
   Using the "type" statement, a type is specified for the annotation
   value according to the same rules as for the type of a YANG
"leaf"[RFC6020bis s.7.6].

I do think that that mention of leaf is helpful - as you say, the WG
agreed to this restriction as opposed to allowing more complex
annotations and referencing "leaf" for me makes that clearer.

Tom Petch

  An annotation carries a single value. The type substatement, which
  must be present, takes as an argument the name of an existing
  built-in or derived type and the value of the annotation must match
  this type. See Section 7.4 of [RFC6020bis] for details.

/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/>