- From: Graham Klyne <gk@ninebynine.org>
- Date: Mon, 23 Jun 2003 16:17:47 +0100
- To: Al Gilman <asgilman@iamdigex.net>, uri@w3.org
At 09:20 23/06/03 -0400, Al Gilman wrote: >At 08:00 AM 2003-06-23, Graham Klyne wrote: >>At 14:35 19/06/03 -0400, Al Gilman wrote: >> >>>At 05:45 AM 2003-06-19, Graham Klyne wrote: >>> >>>>or mid:, defined by RFC 2392, which is clearly non-hierarchical, but: >>>>[[ >>>> mid-url = "mid" ":" message-id [ "/" content-id ] >>>>]] >>>>-- http://www.faqs.org/rfcs/rfc2392.html >>> >>>Please explain in what terms you find the 'mid' scheme to be "clearly >>>non-hierarchical." >> >>I meant in the sense that it does not conform to the normal rules for >>hierarchical URIs; e.g. >> >>given a base URI: >> >> mid:m@example.ord/c@example.org >> >>and a URI-reference: >> >> m2@example.ord/c2@example.org >> >>making an absolute URI from these parts using normal hierarchical URI >>rules would yield: >> >> mid:m@example.ord/m2@example.ord/c2@example.org >> >>which isn't a valid mid: URI. > >But there is no use for the relative URI that you cooked up. > >Just because there are syntactically well-formed but semantically garbage >examples that can be constructed doesn't mean that there is no hierarchy >in the scheme. Just that the hierarchy isn't everything that >you expect. Without wishing to debate the semantic minutiae, I have code based on (my reading of) a previous version of the URI specification that processes the above example and produces a perfectly usable result, namely: mid:m2@example.ord/c2@example.org I.e. it uses just the scheme name from the base URI. The lack of a leading '/' in the base URI path is taken as an indicator that URI hierarchy rules don't apply, so the path component is treated as an opaque item to be replaced by that from the URI reference. Now, maybe my code is wrong. But it seemed to me a reasonable way to write some generic URI handling code that may be called upon to do relative-to-absolute mapping on any pair of URI-references, and it seems to produce results that are reasonable and workable. I find the latest revision of the spec, however, is open to an interpretation in which it is not possible to get a valid URI in this case. That is the basis of my original question -- I don't really care if the example does or does not have any element of hierarchy, but rather that I can understand how to properly process it and (hopefully) obtain a useful or usable result. #g ------------------- Graham Klyne <GK@NineByNine.org> PGP: 0FAA 69FF C083 000B A2E9 A131 01B9 1C7A DBCA CB5E
Received on Monday, 23 June 2003 13:39:22 UTC