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Re: blank nodes question

From: Benja Fallenstein <b.fallenstein@gmx.de>
Date: Mon, 28 Jul 2003 13:23:33 +0200
Message-ID: <3F2507B5.3040904@gmx.de>
To: Bob MacGregor <macgregor@ISI.EDU>
CC: Graham Klyne <GK@ninebynine.org>, "Peter P. Jones" <ppj@concept67.fsnet.co.uk>, www-rdf-interest@w3.org

Bob MacGregor wrote:
> I beg to differ.  Blank nodes are absolutely necessary.
> 
> Consider translating an XML file into RDF, where typically
> none of the incoming resource nodes have URI's.  You have two choices, you
> can use blank nodes to represent them, or you can use (globally
> unique) URI's.  If you use URI's, then you need a scheme for
> generating them so that (1) you don't clash with other uniquely
> generated nodes, (2) you need to figure out how to label
> the nodes each of the subsequent times that you load the same
> graph, (3) you still need a scheme to know that these nodes are
> semantically "blank", so that your application can avoid generating
> "pointers" to them.

Ok, I understand-- if you want to construct deterministic mappings from 
XML files (or other structured forms of data) to RDF, you need the 
bnodes for those parts of the RDF structure for which you do not have a 
URI. And I can understand that you would want to construct such mappings.

So I agree that from that POV, too, bnodes are a good thing.
- Benja
Received on Monday, 28 July 2003 07:25:16 GMT

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