/*
* 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 org.apache.jena.sdb.compiler;
import org.apache.jena.sparql.algebra.Op ;
import org.apache.jena.sparql.algebra.TransformCopy ;
import org.apache.jena.sparql.algebra.op.OpProject ;
import org.apache.jena.sparql.algebra.op.OpSlice ;
public class TransformSliceProject extends TransformCopy
{
@Override
public Op transform(OpSlice opSlice, Op subOp)
{
// (slice (project...)) ==> (project (slice ...))
if ( subOp instanceof OpProject )
{
OpProject p = (OpProject)subOp ;
Op sub = p.getSubOp() ;
Op x = new OpSlice(sub, opSlice.getStart(), opSlice.getLength()) ;
x = new OpProject(x, p.getVars()) ;
return x ;
}
return super.transform(opSlice, subOp) ;
}
}