jena-arq/src/main/java/org/apache/jena/sparql/algebra/OpLib.java

/*
 * 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
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 */

package org.apache.jena.sparql.algebra;

import org.apache.jena.sparql.core.Quad;

public class OpLib
{
    /** Convert a pattern, assumed to be quad form,
     * so that the default graph is the union of named graphs.
     */
    public static Op unionDefaultGraphQuads(Op op)
    {
        // Rewrite so that any explicitly named "default graph" is union graph.
        Transform t = new TransformGraphRename(Quad.defaultGraphNodeGenerated, Quad.unionGraph) ;
        op = Transformer.transform(t, op);
        return op;
    }
}