- From: Keith Moore <moore@cs.utk.edu>
- Date: Fri, 01 Jun 2007 12:55:46 -0400
- To: Robert Sayre <sayrer@gmail.com>
- CC: Mark Nottingham <mnot@mnot.net>, "Roy T. Fielding" <fielding@gbiv.com>, "ietf-http-wg@w3.org Group" <ietf-http-wg@w3.org>, Apps Discuss <discuss@apps.ietf.org>
> That's exactly the argument. If a "more substantial" rewrite does a > better job of documenting HTTP, we should consider it. This > possibility shouldn't cause discomfort, because our shared goal is to > accurately document HTTP 1.1, right? The catch is that HTTP is (currently) specified by RFC 2616, and the most accurate documentation about HTTP is in RFC 2616. If you replace 2616 with a completely different specification, you're not "accurately documenting" HTTP, you're _changing_ the specification. You will inevitably create incompatibilities between "old" HTTP and "new" HTTP. I'm not saying it's inherently a bad idea to do that, I'm saying that a rewrite is going to cause some interoperability issues even if you end up with a much clearer and/or more precise specification. People contemplating a rewrite of HTTP should really look hard that the experience from the DRUMS working group that updated RFC 822 and SMTP. It took a very long time, and while the results are clearer in many ways than the original specifications, IMHO they are not an improvement in every respect. For instance, a lot of effort was spent in rewriting the ABNF that describes internet messages. The new ABNF is perhaps more precise but it's _much_ harder to write a correct parser for the new grammar - and there's very little benefit to doing so because new mail readers still need to be able to parse pre-RFC2822 messages. So in practice, to write a good mail reader, you now need to refer to BOTH RFC 822 and RFC 2822 - because the RFC 822 grammar is the best one to write a parser from, and 2822 has the grammar that you should use when writing code to generate new messages. (And they're in different notations!) This means _more_ work for the implementor, a higher barrier to producing a correct implementation, and a greater temptation to not fully read the specifications and just implement whatever seems to work. Again, I'm not saying don't rewrite the HTTP spec. I'm saying don't underestimate the effort involved, or the harm caused by unintended changes or the difficulty of comparing old and new specifications with different structures. And be really sure you understand how the rewrite is going to benefit the community, taking into account that a lot of implementors won't bother reading the spec and a lot of existing implementations aren't going to get significant updates to conform to the new spec. > Personally, I don't care what color ribbon our pig wins at the county > fair. :) Even if it is cute enough to win a ribbon, do we really need another pig? Keith
Received on Friday, 1 June 2007 16:56:06 UTC