On Wed, May 14, 2025 at 08:41:10AM -0700, Marc Petit-Huguenin wrote: > https://datatracker.ietf.org/doc/draft-rivest-sexp/ is a good example > of a language whose ABNF cannot be normative (that's because the s-exp > variant described in it is non-context free). Even without that, a > normative ABNF would be too complex (if you look closely at my > formalization of that spec, you can understand why). So that's really > an example of the English text be good enough to describe it clearly, > but the formalization too complex for anyone but the purist. That's > why I think that formalizations are best as tools used to generate an > RFC, but are not as useful inside the RFC itself.
ABNF is generally good for the things it's been used for, but it's not really a very good formal language. ASN.1 is much better, though of course you still need a ton of normative natural language. The example RFC regarding ASN.1 as normative would be RFC 5912. It's not possible to write all of RFC 5912's contents as normative natural language text. The _semantics_ of all the things in RFC 5912 require normative natural language text, but the OIDs, the types, the object sets, etc. should be kept in ASN.1. Nico -- _______________________________________________ rfc-interest mailing list -- [email protected] To unsubscribe send an email to [email protected]
