- From: Jeen Broekstra <jeen@aduna.biz>
- Date: Thu, 28 Apr 2005 19:23:14 +0200
- To: Dave Beckett <dave.beckett@bristol.ac.uk>
- Cc: 'RDF Data Access Working Group ' <public-rdf-dawg@w3.org>
Dave Beckett wrote: > I've updated the XML results format editor's draft > > $Revision: 1.24 $ of $Date: 2005/04/25 16:11:26 $ > http://www.w3.org/2001/sw/DataAccess/rf1/ > > to reflect issues brought up and after earlier discussion. Nice job, I think it's a big improvement. I still have a few remarks though :) > The changes are primarily as follows: > > 1. Switched to a form where the variable name is not used as an > element name. It is now of the form <binding name="var"> > > 2. Added a boolean result form for ASK. > > 3. Added sub-elements of binding for the RDF Term types: > <bnode>, <uri>, <literal> Regarding points 1 and 3: I wonder why the <binding> element is necessary. An alternative would be to eliminate it and have the <bnode>, <uri> and <literal> elements directly as subelements of <result>, with the var attribute, like so: <result> <bnode var="x">r2</bnode> <uri var="hpage">http://work.example.org/bob/</uri> <literal var="name" xml:lang="en">Bob</literal> <uri var="mbox">mailto:bob@work.example.org</uri> <literal var="age" xsi:type="xs:integer" datatype="http://www.w3.org/2001/XMLSchema#integer">30</literal> <unbound var="blurb"/> <bnode var="friend">r1</bnode> </result> I guess it comes down to taste as much as anything, but this would be more compact and arguably just as easy to parse/validate. As for point 2, the boolean results format: my colleague Arjohn came up with the following alternatives: Alternative 1: <?xml version="1.0"?> <sparql-ask xmlns="http://www.w3.org/2001/sw/DataAccess/rf1/result2"> <true/> </sparql-ask> Alternative 2: <?xml version="1.0"?> <sparql-ask xmlns="http://www.w3.org/2001/sw/DataAccess/rf1/result2"> <literal xsi:type="xs:boolean" datatype="http://www.w3.org/2001/XMLSchema#boolean>true</literal> </sparql-ask> Using a different root element makes it immediately clear that this is a fundamentally different kind of result - after all, it is not a variable binding result so it seems a bit awkward to try and fit it in the same Schema. A separate XML Schema for boolean results could be trivially simple. Regarding the use of an index attribute for denoting order: I was a bit surprised to see that since I thought the idea was to just add a 'ordered="true"' attribute to the header somewhere and leave ordering up to XML element order. This automatically makes it clear that the ordered result can be processed in a streaming fashion as well. My (and Arjohn's) 2 cents, Jeen -- Jeen Broekstra Aduna BV Knowledge Engineer Julianaplein 14b, 3817 CS Amersfoort http://aduna.biz The Netherlands tel. +31 33 46599877
Received on Thursday, 28 April 2005 17:21:19 UTC