Re: problem with blank node identifiers and rdf:nodeID

From: Jan Grant <Jan.Grant@bristol.ac.uk>
Subject: Re: problem with blank node identifiers and rdf:nodeID
Date: Thu, 28 Nov 2002 16:02:58 +0000 (GMT)

> On Thu, 28 Nov 2002, Peter F. Patel-Schneider wrote:
> 
> > It appears to me that the use of rdf:nodeID makes it impossible to
> > correctly transform an RDF/XML document into n-triples without first
> > checking for all the rdf:nodeID uses in the document.  Otherwise a
> > generated blank node id could accidentally be the same as one used (later)
> > in an rdf:nodeID in the document.
> 
> Simply generate IDs for blank nodes using one prefix; and prefix a
> _different_ thing on the front of all rdf:nodeID-supplied IDs. That
> should be sufficient.

That is not allowed.

The string-value of a blank node is defined to be the concatenation of "_:"
and its identifier.  This identifier is set to be the string-value of
rdf:nodeID attributes.  There is thus no way of using disjoint subsets of
the name space for generated blank node identifiers and blank node
identifiers that come from rdf:nodeID attributes without searching a
document for all the rdf:nodeID attributes it contains.

> Cheers,
> jan

peter