Re: [abnf-discuss] constrained-01

With the work we are doing on naming conventions within managed systems, RFC7405, draft-seantek-abnf-more-core-rules and draft-seantek-constrained-abnf all take ABNF closer to what we need. I would value an RFC that added all their additional features to RFC5234 and an equivalent ABNF parser.

Doug,

Are you talking about preventing ABNF such as the following:

yang-version-arg-str = < a string that matches the rule >
                                              < yang-version-arg >

Jonathan

> -----Original Message-----
> From: abnf-discuss [mailto:abnf-discuss-bounces@ietf.org] On Behalf Of
> Sean Leonard
> Sent: 18 November 2016 19:56
> To: Doug Royer <douglasroyer@gmail.com>
> Cc: abnf-discuss@ietf.org
> Subject: Re: [abnf-discuss] constrained-01 - advantage?
> 
> Hello Doug:
> 
> Thank you...I think?
> 
> ABNF is already “machine-parsable”. A couple of months ago, I published
> (ss)reaex, which is a machine parser (extractor, specifically). Other people
> have written full parser-compilers (apg, bap). The fact that a compiler “can”
> be written for ABNF has always been there, although perhaps it was not a
> design goal of RFC x234.
> 
> I suppose that a goal of draft-seantek-constrained-abnf is to help authors
> make ABNF more machine-parsable, but, that is not the only goal. Another
> goal is to assist specification writers with making their ABNF clearer for
> (human) readers, which means introducing a minimum amount of new
> syntax for specification writers to learn. There are other IETFers who do not
> feel that machine parsing is a (strong) design goal. To that end, another
> design criteria is that ABNF still meets all the criteria of BNF: a context-free
> grammar notation.
> 
> There are other enhancements to RFC 5234 that have been proposed, which
> do take the language further:
> RFC 7405
> draft-seantek-unicode-in-abnf
> draft-seantek-abnf-more-core-rules
> 
> Can you describe what you mean by “needing to go much further”?
> 
> Regards,
> 
> Sean
> 
> > On Nov 19, 2016, at 2:50 AM, Doug Royer <douglasroyer@gmail.com>
> wrote:
> >
> >
> > I do not have a problem with making ABNF machine parsable.
> >
> > This draft makes it possible to make ABNF that is still not machine parsable.
> Because the old difficult to parse methods are still valid.
> >
> > In my opinion, if this draft is going to go forward, this draft will need to go
> much further, because its going to make a confusing mess of mixed ABNF
> usage in future drafts.
> >
> > And much further, its going to be more controversial.
> >
> > --
> >
> > Doug Royer - (http://DougRoyer.US)
> > DouglasRoyer@gmail.com
> > 714-989-6135
> >
> > _______________________________________________
> > abnf-discuss mailing list
> > abnf-discuss@ietf.org
> > https://www.ietf.org/mailman/listinfo/abnf-discuss
> 
> _______________________________________________
> abnf-discuss mailing list
> abnf-discuss@ietf.org
> https://www.ietf.org/mailman/listinfo/abnf-discuss