- From: Biron,Paul V <Paul.V.Biron@kp.org>
- Date: Tue, 19 Mar 2002 14:14:56 -0800
- To: "'David Orchard'" <david.orchard@bea.com>, www-tag@w3.org
> -----Original Message----- > From: David Orchard [SMTP:david.orchard@bea.com] > Sent: Tuesday, March 19, 2002 10:05 AM > To: www-tag@w3.org > Subject: RE: "canonical" URIs > > TAG members, > > I don't see URI comparison officially listed as a TAG issue. I'd like > Joseph/Stephen's issue added to the TAG issues list. > > Equivalence rules for URIs are defined by the URI scheme. HTTP has a > section on URI comparison. > > However, XML does not have a default comparison function for the XML > Schema > anyURI data type. I think a reasonable approach would be to say that the > default comparision function for anyURI is to use the HTTP URI comparison > algorithm, but that it is overridable by any scheme. > Our intention (given enough time I'm sure I could find the minutes documenting this) was that equivalence for xs:anyURI was exactly as stated in the namespaces rec (i.e., "character-by-character", simple binary string compare) but you are right, that is not spelled out (I submitted this issue for a potential erratum). Why? Because it thought it was to be too much of a burden on processors to check things on a scheme-specific basis...plus, what is a processor to do with a scheme that it has never heard of? For what its worth, from a purely schema validation perspective, a comparison/equivalence function on anyURI is only necessary for testing whether a literal is included in a type derived from anyURI with one or more values given for the enumeration facet. pvb
Received on Tuesday, 19 March 2002 17:31:16 UTC