From: Bin Chen <[EMAIL PROTECTED]> I searched some materials about the SIP parser writing, someone mentioned the SIP spec grammer is a ABNF, but not BNF and it's hard to use yacc to parse it. Is it true and I want to know why?
I know yacc can parse LALR grammer and does it has something to do with ABNF and BNF difference? As far as I know, there is no published grammar for SIP. The grammar in section 25.1 of RFC 3261 is not complete, as it has some ambiguities which are resolved by this statement at the end of section 20: The Contact, From, and To header fields contain a URI. If the URI contains a comma, question mark or semicolon, the URI MUST be enclosed in angle brackets (< and >). Any URI parameters are contained within these brackets. If the URI is not enclosed in angle brackets, any semicolon-delimited parameters are header-parameters, not URI parameters. (This statement is also applied to any context where both a name-addr and an addr-spec may appear.) Dale _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
