eburger wrote:
Exercise: write an RFC ?822 parse in yacc. It can be done, but not easily, as the RFC ?822 grammar is not LALR(1).Personally, I don't understand why we didn't just use YACC. One lesson from the DRUMS effort - rewrite an existing grammar at your peril. Even if the old specification has errors, writing a new grammar which verifiably recognizes exactly the same language as the old one can be difficult. And even if you restrict the language that new implementations can emit, you generally have to accept the old language for compatibility's sake. So you end up with two grammars where one was formerly (almost) good enough.I am really in favor of using a formal language for specifying grammar. As Munjo states, the ABNF is essentially documentation fluff - useless at best and wrong at worst.As for this particular suggestion, I am ambivalent as to whether we hack ABNF, adopt YACC, or even adopt ASN.1. Keith |
_______________________________________________ Sip mailing list https://www.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [email protected] for questions on current sip Use [email protected] for new developments on the application of sip
