W3C home > Mailing lists > Public > semantic-web@w3.org > June 2007

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>

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.




-----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)?




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,



This e-mail, and any file transmitted with it, is confidential and  intended solely for the use of the individual or entity to whom it is addressed. If you have received this email in error, please  contact the sender and delete the email from your system. If you are  not the named addressee you should not disseminate, distribute or copy  this email.

For more information on Agence France-Presse, please visit our web site at http://www.afp.com
Received on Saturday, 16 June 2007 16:39:34 UTC

This archive was generated by hypermail 2.4.0 : Tuesday, 5 July 2022 08:45:01 UTC