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

["Martin J. Dürst" <[e-mail]>]

Hello Carsten, others,

On 2022-06-24 03:34, Carsten Bormann wrote:
> On 2022-06-23, at 13:13, Ira McDonald <[e-mail]> wrote:

>> 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.

Well, you actually didn't just make a copy. You replaced a production 
name ('grandfathered' -> 'legacy'), you removed the comments from the 
'irregular' and 'regular' productions to make them take less space, and 
you added productions for ALPHA and DIGIT. I don't think you introduced 
any errors, but it's changes like these that may start a slippery slope 
or introduce subtle errors.


> 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...

There's a wide gap between "fragile" and "not set in stone". The grammar 
in RFC 5646 is not set in stone, but to call it "fragile" is overstating 
the issue.

But what's important is that technologies, in the IETF as well as 
elsewhere, should only be linked as strongly as needed, not more 
strongly. That way, technology can evolve more independently and freely, 
with less needs for implementation or specification changes.

[One of the main places where the I18N community learned this was that 
in the mid 1990es, at one point everybody was very happy to get certain 
specs (e.g. HTML) to cite Unicode. But when a year later Unicode was 
updated, we started to get questions about whether the spec in question 
also could be used with the newly added characters. The answer should 
have been "yes, of course", but the specs were not written that way. 
After hashing things out, Unicode now provides reference examples for 
both versioned and versionless references (see 
https://www.unicode.org/versions/index.html#References).]

> 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.)

I don't know enough about CDDL to be able to say whether that is a good 
thing or not.

Regards,   Martin.

> Grüße, Carsten