W3C home > Mailing lists > Public > public-rdf-wg@w3.org > May 2013

Proposed text for issue-118

From: Pat Hayes <phayes@ihmc.us>
Date: Tue, 30 Apr 2013 20:24:45 -0500
Message-Id: <88C154F4-563B-49E8-9747-88606EE86EF0@ihmc.us>
To: W3C RDF WG <public-rdf-wg@w3.org>

Proposed text changes:

In Semantics

<end of section 4 defining simple interpretations, add a paragraph:>

Semantic extensions may impose further constraints upon interpretation mappings, by requiring some IRIs to refer in particular ways. For example, D-interpretations, described below, require some IRIs, understood as referring to datatypes. to have a fixed interpretation. Such an IRI is called a <em>rigid identifier</em>.

<section 7, literlas and datatypes.>

.... Datatypes are indicated by IRIs.

Interpretations will vary according to which IRIs they recognize as denoting datatypes. We describe this using a parameter D on interpretations. where D is a set of IRIs that constitute the recognized datatype IRIs and which are considered to be rigid identifiers. If D includes any of the datatype IRIs listed in ///Concepts Section 5/// then they must be interpreted as described there, and the IRI rdf:plainLiteral must be interpreted to refer to the datatype defined in [RDF-PLAINLITERAL]. When other datatypes are used, all recognized IRIs [[must]] be treated as rigid identifiers, so that the mapping between a recognized IRI and the datatype it refers to must be specified unambiguously and treated as fixed during all RDF transformations or manipulations. 


In Concepts:

1.3  The Referent of an IRI

The resource denoted by an IRI is also called its referent. For some IRIs with particular meanings, such as those identifying XSD datatypes, the referent is fixed by this specification. For all other IRIs, what exactly is denoted by any given IRI is not defined by this specification. Other specifications may fix IRI referents, or apply other constraints on what may be the referent of any IRI. 

5.4 Datatype IRIs

Datatypes are identified by IRIs. If D is a set of IRIs which are used to refer to datatypes, then the elements of D are called <em>recognized</em> datatype IRIs. Recognized IRIs are considered to be rigid identifiers. All semantic interpretations must conform to a fixed mapping between recognized IRIs and the datatypes they are specified to identify. All interpretations I [[must]] recognize the following IRIs with the mappings specified:

I( http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral ) is the datatype rdf:XMLLiteral ;
I( http://www.w3.org/1999/02/22-rdf-syntax-ns#HTM ) is the datatype rdf:HTML ;
I( http://www.w3.org/2001/XMLSchema#xxx ) is the RDF-compatible XSD type named xsd:xxx, for every XSD type listed in section 5.1

Semantic extensions of RDF [[may]] recognize other datatype IRIs and impose fixed interpretations upon them, but they [[must not]] interpret a datatype IRI differently from its defining specification.


I would also like to say something along the following lines, but I am not sure where it should go exactly.


Applications [[may]] give a warning message if they are unable to determine the referent of an IRI used in a typed literal, but they [[should not]] reject such RDF as either a syntactic or semantic error. 


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Received on Wednesday, 1 May 2013 01:25:10 UTC

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