- From: Graham Klyne <GK@ninebynine.org>
- Date: Wed, 23 Jan 2002 10:19:51 +0000
- To: "Jonathan Borden" <jborden@mediaone.net>
- Cc: <www-rdf-comments@w3.org>
Jonathan, You make fair comments, I think. I think this (particularly your 3rd paragraph below) touches on a related issue [1], which I believe clearly is architectural, namely the use of a URI+fragment in RDF as a "first class resource identifier" not being entirely consistent with its use in the wider web. I think this is an issue that probably needs to be resolved in a forum with broader scope than RDFcore (such as TAG?), because at heart it relates to compatibility between different systems. For itself, not taking account of alternative XML usage, I still think that RDF is reasonably self-consistent. #g [1] http://www.w3.org/2000/03/rdf-tracking/#rdfms-fragments (and in particular, my point 1 in: http://lists.w3.org/Archives/Public/www-rdf-interest/2000Sep/0032.html ) At 12:37 AM 1/23/02 -0500, Jonathan Borden wrote: >Graham Klyne wrote: > >" >The forward transformation from QName -> URI is clear and unambiguous per >the original RDF specification. It is the reverse transformation that is >problematic. >" > >To be clear, while I would prefer that a bidirectional mapping be possible, >just as I would _greatly_ prefer that the RDF model <-> XML mapping be >bidirectional and roundtripable, there are issues with the simple forward >transformation. > >In particular the model XML Schema uses for use of a QName as a type >specifier is that the namespace name/URI is like the 'base URI' of the >schema (quotes because it is not quite that simple but nonetheless) and that >the localname is used as a locator for the type declaration within the >schema module. In URI terms, XML Schema thus treats the localname LIKE a >fragment identifier. It is not exactly a fragment identifier for several >reasons, namely that no fragment identifer syntax is (yet)defined for >application/xml and particularly because the localname maps to the XML >Schema "name" attribute which is not ot type ID. > >For this reason I have issues with the forward QName -> URI mapping if this >is a simple string concatenation. > >For the vast majority of RDF namespaces, perhaps all of the deployed RDF >namespaces, simple concatenation is exactly the same as treating the >localname as a fragment identifier (it comes after the '#') but for XML >namespaces in general this is not the case. RDF does not require its >namespaces to end in '#' hence one of the reasons for the incompatibility. > >I cannot say for sure that this incompatibility is entirely the 'fault' of >RDF (although the mapping is perhaps too simplistic), rather a breakdown in >communications and coordination between the RDF WG and other WGs more >intimately involved in XML activities. It is not important to me where this >incompatibility gets fixed, and since it is a basic architectural issue I >agree with Brian and Tim Bray that the TAG ought be involved in this issue. >For that reason alone, I would prefer that the issue not be closed for the >moment. > >Jonathan ------------ Graham Klyne GK@NineByNine.org
Received on Wednesday, 23 January 2002 06:24:21 UTC