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RE: Can an XPath expression be considered as a

From: Laurent LE MEUR <Laurent.LEMEUR@afp.com>
Date: Sat, 16 Jun 2007 18:39:21 +0200
Message-ID: <C7BF0FC162538147816C20977E693DF806127A71@SPAR-EXCH-0A.afp.local>
To: "Jacco van Ossenbruggen" <Jacco.van.Ossenbruggen@cwi.nl>
Cc: <iptc-news-architecture-dev@yahoogroups.com>, <semantic-web@w3.org>
Jacco, 

Thanks for your answer.

 

I infer from your statement (please confirm) that there is no problem with the following N3:

 

<//*[@id='person1' or @id='person2']> nar:conceptId pers:gw.bush .

 

or even 

{ <//*[@id='person1' or @id='person2']> nar:conceptId pers:gw.bush } nar:confidence 70 .

 

Note that the XPath expression may be really more complex than this example, which could also be simply expressed as:

<#person1> newsml:name pers:gw.bush .

<#person2> newsml:name pers:gw.bush .

 

I thought that an XPath expression was not a fragment identifier if not wrapped in an xpointer(), and therefore was not a valid URI Reference.

 

Laurent

 

-----Message d'origine-----
De : Jacco van Ossenbruggen [mailto:Jacco.van.Ossenbruggen@cwi.nl] 
Envoyé : samedi 16 juin 2007 17:15
À : Laurent LE MEUR
Cc : semantic-web@w3.org; iptc-news-architecture-dev@yahoogroups.com
Objet : Re: Can an XPath expression be considered as a

 

Laurent LE MEUR wrote:  

> 

> Now our problem: we want to be able to transform such assertions to 

> RDF triples. The subject of the triple is a piece of text: can an 

> XPath expression be an acceptable identifier for an RDF subject (my 

> take is that it must be a URI, and an XPath expression is not a URI)?

> 

Laurent,

 

Having an XPath expression as the fragment identifier (the part after 

the '#') results, AFAIK, in perfectly valid RDF.  (Your average 

non-XPath aware RDF-processor would  not be able to _interpret_ these 

fragment identifiers, but this is not be necessary to allow it to do all 

the normal RDF processing you would want it todo).

> 

> If not, what are the good triples we can get from such a structure? I 

> looked at Annotea to find guidelines, and found that the piece of text 

> (represented by an XPointer in Annotea) is the value of the context 

> property of a resource which is the annotation itself (see 

> http://www.w3.org/2001/Annotea/Plan/context/newcontext.html). Is it 

> the SemWeb definitive view on it?

> 

With all respect for Marja-Riitta, the document you are referring to is 

dated January 2003... 

 

Personally, I do not see the added value of having the extra complexity 

of the context property described there over just putting the 

XPath/XPointer in the rdf:about attribute.

 

Hope this helps,

 

Jacco





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Received on Saturday, 16 June 2007 16:39:34 UTC

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