/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hp.hpl.jena.sdb.compiler.rewrite;
import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.sdb.compiler.QuadBlock;
import com.hp.hpl.jena.sdb.core.SDBRequest;
import com.hp.hpl.jena.sparql.core.Quad;
import com.hp.hpl.jena.sparql.core.Var;
import com.hp.hpl.jena.vocabulary.RDF;
import com.hp.hpl.jena.vocabulary.RDFS;
public class QBR_SubType implements QuadBlockRewrite
{
private static final Node rdfType = RDF.type.asNode() ;
@Override
public QuadBlock rewrite(SDBRequest request, QuadBlock quadBlock)
{
// Does not consider if the property slot is a variable.
if ( ! quadBlock.contains(null, null, rdfType, null) )
return quadBlock ;
quadBlock = new QuadBlock(quadBlock) ;
int i = 0 ;
// Better/clearer : do as copy over from one block to another.
while ( ( i = quadBlock.findFirst(i, null, null, rdfType, null) ) != -1 )
{
// { :s rdf:type :C } => { :s rdf:type ?V . ?V rdfs:subClassOf :C }
Quad rdfTypeQuad = quadBlock.get(i) ;
Var var = request.genVar() ;
Quad q1 = new Quad(rdfTypeQuad.getGraph(), rdfTypeQuad.getSubject(), rdfType, var) ;
Quad q2 = new Quad(rdfTypeQuad.getGraph(), var, RDFS.subClassOf.asNode(), rdfTypeQuad.getObject()) ;
quadBlock.set(i, q1) ; // replace rdf:type statement
quadBlock.add(i+1, q2) ; // add subClassOf statement
i = i+2 ; // Skip the two statements.
}
return quadBlock ;
}
}