Re: [core] [Last-Call] [art] Artart last call review of draft-ietf-core-problem-details-05

[tom petch <[e-mail]>]

On 23/06/2022 22:08, Ira McDonald wrote:
> Hi Carsten,
>
> I take your point about copying from a given RFC.
>
> But the history of IETF Language Tags is RFC 1766 (1995), RFC 3066 (2001),
> RFC 4646 (2006), and RFC 5646 (2009).  It's a long time since 2009 and, as
> Martin noted, there have been a variety of proposals for updating language
> tags in the past 13 years, so it's reasonably likely that there will be a
> newer
> version at some point.  And since language tags are now quite structured,
> the chance of not needing syntax changes is fairly low.  This draft RFC from
> CORE wouldn't catch up quickly, presumably.

Probably a left field comment.

I had not heard of, or forgotten about, language tags until the IESG 
review of draft-ietf-i2nsf-nsf-facing-interface-dm drew a DISCUSS from 
Francesca because the 26 YANG string that were meant to be human 
readible had no language tags.  She pointed to RFC2277 while saying that 
RFC5646 should be a Normative Reference.

The I-D was revised to include a YANG leaf 'language' with a horrendous 
YANG pattern spanning 25 lines.

Two consequences.  The pattern, doubtless a gross simplification of what 
it might have been, was wrong and was revised - I have not looked to see 
if it makes sense now but then I did not spot the error in the first 
place - so I have the sense that, like trying to specify a pattern for 
IPv6 address, language tags are easy to get wrong.  Second there is now 
a pattern of Francesca throwing DISCUSS at other similar I-D so language 
tags, and their modelling in YANG, could get more attention (at least 
while Francesca is on the IESG:-) her comments could have been made 
about any number of earlier YANG RFC).  The pattern in the I2NSF I-D 
cannot be imported into another YANG module, rather each YANG module 
that draws a DISCUSS will contain a fresh copy.  If ideas evolve, then 
there are likely to be many disparate copies.

Tom Petch

>
> Cheers,
> - Ira
>
>
>
> *Ira McDonald (Musician / Software Architect)*
>
>
> On Thu, Jun 23, 2022 at 2:34 PM Carsten Bormann <[e-mail]> wrote:
>
>> On 2022-06-23, at 13:13, Ira McDonald <[e-mail]> wrote:
>>>
>>> Hi Carsten,
>>>
>>> OK - you need to get this CORE document published quickly.
>>
>> Thank you.
>>
>>> But I still think that detailed CDDL would be a long-term mistake, for
>> the reason
>>> that Martin cited - i.e., copying/transforming grammars among RFCs is
>> fragile.
>>
>> Well, the RFC is immutable, so the act of making a copy cannot by itself
>> be fragile.
>>
>> What got us to now propose blunting that grammar is the strong impression
>> that there may be less consensus about the grammar defined by RFC 5646 than
>> we thought.  So it seems the grammar in RFC 5646 is fragile, not the act of
>> copying it out...
>>
>> https://github.com/core-wg/core-problem-details/pull/40/commits/bbe72e2
>>
>> (I’m making a point about copying here as I believe copying out snippets
>> of CDDL from RFCs and other specifications will be a significant part of
>> CDDL 2.0.)
>>
>> Grüße, Carsten
>