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Re: Proposal:#rdfms-identity-anon-resource

From: Stefan Kokkelink <skokkeli@mathematik.uni-osnabrueck.de>
Date: Thu, 12 Jul 2001 09:38:28 +0200
Message-ID: <3B4D53F4.8A8002B5@mathematik.uni-osnabrueck.de>
To: RDF interest group <www-rdf-interest@w3.org>
Graham Klyne:
> All,
> 
> With reference to my previous message:
> 
>    http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2001Jul/0024.html
> 
> there's not been an overwhelming response concerning the key question
> raised, but some muted agreement with the suggestion that this is really a
> syntactic issue.
> 
> By way of a reminder, the key question was:
> 
>    1. Are anonymous resources allowed in the abstract graph syntax?
> 
> In order to either (a) declare a quick victory, or (b) flush out the
> objections, I'm going to assume the answer is "no" and make a proposal for
> resolution of this issue.
> 
> PROPOSAL:
> 
> Anonymous resources may appear in the XML serialization of an RDF graph,
> but they have no distinguished representation in the abstract syntax of RDF.
> 
> It is the responsibility of an RDF/XML parser to assign a unique URI for
> any resource that is not explicitly named.  The essential property of a
> unique URI is that the same URI is not used as the explicitly given or
> automatically generated identifier of any other element in any graph that
> contains the uniquely generated URI.
> 
> No specific mechanism for generating such URIs is mandated, but the
> following options might be considered:
> (a) relative URI forms in the generated graph.
> (b) uuid URIs.
> (c) URIs containing identification of the RDF parser.
> (d) URIs containing large random values.

Hi Graham,

(b) flush out the objections

Here it goes ... ;-)

I think we will get into big trouble if we force parsers to
invent a name for something that does not have a name.

1. An important application of RDF is the join of RDF graphs:
By now named resources (with identical URI) are glued together,
but anonymous are not. Please don't change this.

2.1 By now parsers can use their own mechanisms to create an
*internal* identifier for anonymous resources. They don't have
to implement complex algorithms, and

2.1 I don't think there exists an algorithm that fulfills
the requirement of your 'essential property of a unique URI'
you mentioned above.

Anonymous resources should be part of the model.
At the moment, they are part of the model, and,
in my opinion, this should be explicitly stated.

Regards,
Stefan
Received on Thursday, 12 July 2001 03:40:07 GMT

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