/*
* 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.sparql.algebra;
import org.apache.jena.sparql.algebra.op.* ;
// NB Operations take and return nulls for convenience.
public class OpLib
{
public static Op sub(Op1 op) { return op==null ? null : op.getSubOp() ; }
public static boolean isProject(Op op) { return op instanceof OpProject ; }
public static OpProject asProject(Op op)
{ return isProject(op) ? (OpProject)op : null ; }
public static boolean isDistinct(Op op) { return op instanceof OpDistinct ; }
public static OpDistinct asDistinct(Op op)
{ return isDistinct(op) ? (OpDistinct)op : null ; }
public static boolean isReduced(Op op) { return op instanceof OpReduced ; }
public static OpReduced asReduced(Op op)
{ return isReduced(op) ? (OpReduced)op : null ; }
public static boolean isOrder(Op op) { return op instanceof OpOrder ; }
public static OpOrder asOrder(Op op)
{ return isOrder(op) ? (OpOrder)op : null ; }
public static boolean isSlice(Op op) { return op instanceof OpSlice ; }
public static OpSlice asSlice(Op op)
{ return isSlice(op) ? (OpSlice)op : null ; }
}