[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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