W3C home > Mailing lists > Public > semantic-web@w3.org > July 2009

Re: Explicit RDF property for "literal has datatype D"?

From: Pat Hayes <phayes@ihmc.us>
Date: Mon, 6 Jul 2009 12:05:30 -0500
Cc: Christoph LANGE <ch.lange@jacobs-university.de>, Semantic Web <semantic-web@w3.org>, Siarhei Uladzimiravich Kuryla <s.kuryla@jacobs-university.de>
Message-Id: <F6934734-E085-410B-9E64-D1B2107D15DD@ihmc.us>
To: Toby A Inkster <tai@g5n.co.uk>

On Jul 6, 2009, at 9:53 AM, Toby A Inkster wrote:

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> On 6 Jul 2009, at 14:34, Christoph LANGE wrote:
>
>> p a rdf:Property ;
>>  rdfs:domain rdfs:Literal ;
>>  rdfs:range rdfs:Datatype .
>
>
> In terms of RDF, this can't be done. Well, the property could be  
> defined using RDFS, but it could never legally be used. The  
> definition would imply that "p" is used like so:
>
> 	"2008-01-01" p xsd:date .

rdfs:Literal is the class of literal VALUES, and bnodes and URIs can  
denote literal values. So you could use a bnode:

_:x p xsd:date .
_:x :seenAsLiteral  "2008-01-01" .

(I made up the second property, but you get the idea.)
OR, you could just ignore this damn silly syntactic restriction and  
put the literal in the subject, like many RDF systems now do.

Pat Hayes

>
> However, RDF doesn't allow a literal to be used as the subject of a  
> triple. Hence there is no property defined like the "p" you  
> describe. There are supersets of RDF (such as Notation 3) which  
> relax this restriction and would allow a property "p" like you  
> describe to be used.
>
> - --
> Toby A Inkster
> <mailto:mail@tobyinkster.co.uk>
> <http://tobyinkster.co.uk>
>
>
>
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.8 (Darwin)
>
> iEYEARECAAYFAkpSEAQACgkQzr+BKGoqfTnHfQCfV50trF0sL9InwG08FgvQfbDQ
> mBQAnA3dot8UHlT5bmvLtUycwQhAwYSB
> =cB/I
> -----END PGP SIGNATURE-----
>
>
>

------------------------------------------------------------
IHMC                                     (850)434 8903 or (650)494 3973
40 South Alcaniz St.           (850)202 4416   office
Pensacola                            (850)202 4440   fax
FL 32502                              (850)291 0667   mobile
phayesAT-SIGNihmc.us       http://www.ihmc.us/users/phayes
Received on Monday, 6 July 2009 17:06:24 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 1 March 2016 07:42:13 UTC