- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Thu, 24 Jun 2004 10:37:18 +0100
- To: public-rdf-dawg@w3.org
I have done a prototype implementation of some of BRQL by adding features to Jena's RDQL implementation: CONSTRUCT DESCRIBE OPTIONAL It also passes the RDQL JUnit test suite in Jena. As the prototype took one day, don't expect a reliable, solid implementation. Indeed, it is no more than proof of concept. There are various limitations and you can write very silly queries involving CONSTRUCT and OPTIONAL (they will fail at run time but they should be parser errors). Implementation (a whole Jena installation with BRQL) http://jena.hpl.hp.com/~afs/Jena-2.1-brql-1.zip Run the command "java -cp ... jena.rdfquery ....." to run BRQL. Some trivial examples are run by the script "examples" in: http://jena.hpl.hp.com/~afs/brql-examples.zip Most of the time went into the OPTIONALs parts - it is a streaming evaluation of queries with (multiple) optional clauses. Bindings in one optional part are allowed to effect another optional part with evaluation being in the order the clauses appear in the query. This is untested and unchecked - it wasn't an objective for this initial prototype. Restrictions: DESCRIBE <uri> not done. DESCRIBE is done by bNode graph closure and is fixed in this implementation. Indeed, the Java interface to DESCRIBE results is going to be reworked. Andy
Received on Thursday, 24 June 2004 05:37:35 UTC