[rdfweb-dev] namespace versioning

Ian Davis iand at internetalchemy.org
Tue Jul 27 23:46:57 UTC 2004


On 27/07/2004 16:33, Julian Bond wrote:
> And how does it work? If you are parsing RDF with references to an old 
> namespace, the parser will have to be told that it can be replaced with 
> a newer one. Before the Application can then search for the triples that 
> use the new one.
> 
That's handled through the inference rules in RDF Schema and OWL. For 
example, if you declare rel:friendOf to be a sub property of foaf:knows 
then the RDF Schema rules tell you to add a triple <x foaf:knows y> 
whenever you see <x rel:friendOf y>. You could implement owl:sameAs in a 
similar fashion.

These sub property and same as declarations are found in the relevant 
schema file (e.g. 
http://purl.org/vocab/relationship/rel-vocab-20040308.rdf). Just load 
the schema into the same model as the RDF file you've just parsed and 
trigger the rules.

If you implement these rules then your queries only need to use a single 
namespace rather than pattern matching.

And yes, in an ideal world, this kind of code would be built into the 
parser out of the box.

Ian



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