Re: [abnf-discuss] Mail regarding draft-seantek-constrained-abnf

[Sean Leonard <[e-mail]>]

> On Jul 8, 2016, at 3:39 PM, Paul Kyzivat <[e-mail]> wrote:
> 
> [...]
> 
> "Defined over X" could be a predicate that a verifier could decide for a given ABNF grammar. [...]
> 
> "Defined over ASCII" and "Defined over Unicode" could also be determined by analysis of the grammar.

Up to this point, that is determined by (human) analysis of the specification text. It’s worked out overall.

As much as I would like to see some more Unicode action, we already have two proposals on the table that I would like to focus on and get adopted & passed, before working on new stuff. The proposals are abnf-more-core-rules and constrained-abnf.

In abnf-more-core-rules, there already are mechanisms for incorporating Unicode, in the productions:
 UNICODE
 BEYONDASCII
 C1
 BEYONDC1 (to be included in next draft)

I suppose the following could be added:
 LATIN1
 BEYONDLATIN1

I submit that these mechanisms are probably “quite enough” for IETF usage. There is a strong bias in ABNF for ASCII, which basically reflects the institutional bias in the IETF for US-English and the history of the Internet’s development. I have yet to see an IETF standard that calls out a specific character beyond the ASCII range and gives it special semantics (other than NEL, and even then, NEL is not really used).


Sean