- From: Pierre-Antoine Champin <pierre-antoine.champin@liris.cnrs.fr>
- Date: Thu, 10 Mar 2011 09:32:37 +0100
- To: "Evain, Jean-Pierre" <evain@ebu.ch>
- CC: "public-media-annotation@w3.org" <public-media-annotation@w3.org>
Hi Jean-Pierre, just to make things clearer: the values of a datatype property are always "literals". However, in RDF, literals may have different forms: * they can have a language tag * they can have a datatype * they can have none of the two above * they can not have a language tag *and* a datatype the last two points are sometimes considered a design default in RDF, and will perhaps be fixed by the current RDF WG. But for the moment, only "untyped" literals can have a language tag. In OWL, the range of a datatype property specifies what kind of literal are expected as values of this property. If the range is a datatype (xsd:integer, xsd:date, xsd:string...), that will be typed literals with that datatype (and hence no language tag). If the range is rdfs:Literal, that will be untyped literals (hence possibily with a language tag). Datatypes like xsd:int or xsd:date bring some semantics compared to untyped literals. However, xsd:string has no added value: it has the same value space as untyped literals, but does not allow language tags. Hence my suggestion to : - replace xsd:string by rdfs:Literal for all datatype-properties having xsd:string, - keep all other range axioms untouched, as they add semantics (and language tags do not really make sense for integers, doubles or dates, anyway) I did a quick test: datatype with range rdfs:Literal do validate OWL-RL. pa On 03/09/2011 08:29 PM, Evain, Jean-Pierre wrote: > Pierre-Antoine, > > I am reading a lot of material on the use of rdfs:literal combined with xml:lang. I see all sort of opinions sometimes negative. > > Still, I guess if we go for literal it would need to be applied more systematically and not only to strings probably using typed literals?? > > Jean-Pierre > > -----Original Message----- > From: Evain, Jean-Pierre > Sent: mercredi, 9. mars 2011 19:31 > To: Evain, Jean-Pierre; 'Pierre-Antoine Champin'; public-media-annotation@w3.org > Subject: RE: datatype properties' range > > Pierre-Antoine, > > If I get you right you want to type the literal with a language or...? > > Regards, > > Jean-Pierre > > -----Original Message----- > From: public-media-annotation-request@w3.org [mailto:public-media-annotation-request@w3.org] On Behalf Of Evain, Jean-Pierre > Sent: mercredi, 9. mars 2011 19:17 > To: 'Pierre-Antoine Champin'; public-media-annotation@w3.org > Subject: RE: datatype properties' range > > Pierre-Antoine, > > About changing 'xsd:string' to rdfs:literal. > > In this case would it be logical to make a similar change to datatype properties with e.g. integer content? > > There would also likely be a need to check compliance with OWL-RL or another profile, if we care? > > Regards, > > Jean-Pierre > > -----Original Message----- > From: public-media-annotation-request@w3.org [mailto:public-media-annotation-request@w3.org] On Behalf Of Pierre-Antoine Champin > Sent: mercredi, 9. mars 2011 16:44 > To: public-media-annotation@w3.org > Subject: datatype properties' range > > Hi all, > > in the RDF ontology, all datatype properties with textual content have > range xsd:string. > > I think using rdfs:Literal instead would be beneficial, as we could > (optionally) add a language tag to those textual values. > > I mention it because the API document allows to attach a language > information to virtually any property value. This would be a nice way to > encode this in RDF as well. > > pa > > > ----------------------------------------- > ************************************************** > This email and any files transmitted with it > are confidential and intended solely for the > use of the individual or entity to whom they > are addressed. > If you have received this email in error, > please notify the system manager. > This footnote also confirms that this email > message has been swept by the mailgateway > **************************************************
Received on Thursday, 10 March 2011 08:33:34 UTC