W3C home > Mailing lists > Public > public-rdf-in-xhtml-tf@w3.org > March 2008

Re: test case 0011

From: Ivan Herman <ivan@w3.org>
Date: Wed, 05 Mar 2008 13:06:59 +0100
Message-ID: <47CE8CE3.9010104@w3.org>
To: Mark Birbeck <mark.birbeck@x-port.net>
CC: Johannes Koch <koch@w3development.de>, public-rdf-in-xhtml-tf@w3.org
Well, back to the 'ouch' mode:-(

- I ran some quick tests on my local sparql engine (sparqler) as well my 
local virtuoso engine. It looks as if they did not work properly; I 
could not get the right answers. I did not test it extensively, though, 
I may have missed something.

- but it we really have to produce an exclusive canonicalization of the 
XML literal, then yes, back to the 'ouch' mode, and even more than ever. 
  For example, I have no idea whether there is an ExCan implementation 
in python, let alone how I would have to interface it to the rest... And 
implementing it from scratch, though doable of course, is a royal pain...

Ivan

Mark Birbeck wrote:
> Hi Ivan,
> 
> Just to put some more meat on the bones of my other email:
> 
>>  [snip]
>>
>>  Then the generated RDF can either be:
>>
>>  <> <dc:title> "<span xmlns="http://www.w3.org/1999/xhtml" class="bla">E
>>
>> = mc<sup>2</sup>: The Most Urgent Problem of Our
>>
>> Time</span>"^^xsd:XMLLiteral
>>
>>  but it could also be:
>>
>>  <> <dc:title> "<span xmlns="http://www.w3.org/1999/xhtml" class="bla">E
>>  = mc<sup xmlns="http://www.w3.org/1999/xhtml>2</sup>: The Most Urgent
>>  Problem of Our Time</span>"^^xsd:XMLLiteral
>>
>>  which is, from an XML point of view, identical. The problem is that I am
>>  simply not sure whether the SPARQL engines compare XML Literals
>>  textually or 'semantically', so to say...
> 
> This is ok, as it happens, since it's covered by Exclusive
> Canonicalisation [1]. You should *always* get:
> 
>   <> <dc:title> "<n0:span xmlns:n0=\"http://www.w3.org/1999/xhtml\"
>     class=\"bla\">E = mc<n0:sup>2</n0:sup>: The Most Urgent Problem
>     of Our Time</n0:span>"^^xsd:XMLLiteral
> 
> (And note that Exclusive Canonicalisation is what is referred to in
> RDF Concepts.)
> 
> Regards,
> 
> Mark
> 
> [1] <http://www.w3.org/TR/xml-exc-c14n/>
> 

-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf

Received on Wednesday, 5 March 2008 12:07:06 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:50:27 UTC