- From: <noah_mendelsohn@us.ibm.com>
- Date: Tue, 29 Apr 2003 19:16:21 -0400
- To: "Roy T. Fielding" <fielding@apache.org>
- Cc: Dan Connolly <connolly@w3.org>, WWW-Tag <www-tag@w3.org>
Roy Fielding writes: >> No, the heart of the matter is whether the XML >> Namespaces specification has the authority to >> say that normalization is not allowed, which is >> what the text currently says because it is >> over-specifying the matter. I wonder whether we need to distinguish the license we might give an application to do normalization, vs. any latitude in the mechanisms of XML and Namespaces themselves. Consider this example: <e p:a="1" q:a="2" xmlns:p="http://example.org/x" xmlns:q="http://EXAMPLE.ORG/x" /> Does this or does it not violate the Uniqueness of Attribute constraint of Namespaces 1.1 [1]? I hope we have an unambiguous answer to that question. Roy, are you implying that there should be lattitude for some processors to accept the document and others not? I suggest that for Uniqueness of Attributes and similar purpose we need a single, interoperable answer. The document is either OK or it's not. My preferred answer would be "strcmp applies, the above document is OK". In that sense, the namespaces 1.1 CR is OK as it stands, I think. I have no objection to a formulation that grants lattitude for higher level applications to consider the two URIs above to be the same (per 2396), and thus at the application level to consider the two attributes above as being duplicates. I don't think I want to require XML processors to detect them as duplicate, or for XML schema to decline to allow separate declarations for them. So, the core XML mechanisms will unfortunately do a poor job of helping applications to do the right thing. This all seems to be an area where the demands of both performance and manageability (I.e. the difficulties in deploying new software to handle URI canonicalization rules for newly invented schemes) make it difficult to do what would otherwise be architecturally correct: to follow RFC 2396 in all cases where URI comparison is to be done. So, we should not be surprised that the solutions are in some respects ugly; the core XML mechanisms will be somewhat out of sync with what might otherwise be desireable. Noah [1] http://www.w3.org/TR/2002/CR-xml-names11-20021218/#uniqAttrs ------------------------------------------------------------------ Noah Mendelsohn Voice: 1-617-693-4036 IBM Corporation Fax: 1-617-693-8676 One Rogers Street Cambridge, MA 02142 ------------------------------------------------------------------
Received on Tuesday, 29 April 2003 19:24:53 UTC