/*
* 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.sparql.algebra.op;
import com.hp.hpl.jena.sparql.algebra.Op ;
import com.hp.hpl.jena.sparql.algebra.OpVisitor ;
import com.hp.hpl.jena.sparql.algebra.Transform ;
import com.hp.hpl.jena.sparql.expr.Expr ;
import com.hp.hpl.jena.sparql.expr.ExprList ;
import com.hp.hpl.jena.sparql.sse.Tags ;
import com.hp.hpl.jena.sparql.util.NodeIsomorphismMap ;
public class OpFilter extends Op1
{
ExprList expressions ;
public static Op filter(Expr expr, Op op)
{
OpFilter f = filter(op) ;
f.getExprs().add(expr) ;
return f ;
}
public static OpFilter filter(Op op)
{
if ( op instanceof OpFilter )
return (OpFilter)op ;
else
return new OpFilter(op) ;
}
public static Op filter(ExprList exprs, Op op)
{
if ( exprs.isEmpty() )
return op ;
OpFilter f = filter(op) ;
f.getExprs().addAll(exprs) ;
return f ;
}
// public static Op filterRaw(ExprList exprs, Op op)
// {
// if ( exprs.isEmpty() )
// return op ;
// OpFilter f = new OpFilter(exprs, op) ;
// return f ;
// }
/** Make a OpFilter - guarantteed to return an OpFilter */
public static OpFilter filterDirect(ExprList exprs, Op op)
{
return new OpFilter(exprs, op) ;
}
private OpFilter(Op sub)
{
super(sub) ;
expressions = new ExprList() ;
}
private OpFilter(ExprList exprs , Op sub)
{
super(sub) ;
expressions = exprs ;
}
/** Compress multiple filters: (filter (filter (filter op)))) into one (filter op) */
public static OpFilter tidy(OpFilter base)
{
ExprList exprs = new ExprList() ;
Op op = base ;
while ( op instanceof OpFilter )
{
OpFilter f = (OpFilter)op ;
exprs.addAll(f.getExprs()) ;
op = f.getSubOp() ;
}
return new OpFilter(exprs, op) ;
}
public ExprList getExprs() { return expressions ; }
@Override
public String getName() { return Tags.tagFilter ; }
@Override
public Op apply(Transform transform, Op subOp)
{ return transform.transform(this, subOp) ; }
@Override
public void visit(OpVisitor opVisitor) { opVisitor.visit(this) ; }
@Override
public Op1 copy(Op subOp) { return new OpFilter(expressions, subOp) ; }
@Override
public int hashCode()
{
return expressions.hashCode() ;
}
@Override
public boolean equalTo(Op other, NodeIsomorphismMap labelMap)
{
if ( ! (other instanceof OpFilter) ) return false ;
OpFilter opFilter = (OpFilter)other ;
if ( ! expressions.equals(opFilter.expressions) )
return false ;
return getSubOp().equalTo(opFilter.getSubOp(), labelMap) ;
}
}