Github user ajs6f commented on a diff in the pull request: https://github.com/apache/jena/pull/337#discussion_r159252167 --- Diff: jena-arq/src/main/java/org/apache/jena/sparql/util/ViewDatasetGraph.java --- @@ -0,0 +1,225 @@ +/* + * 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.util; + +import static java.util.Objects.requireNonNull; +import static org.apache.jena.atlas.iterator.Iter.count; +import static org.apache.jena.atlas.iterator.Iter.map; +import static org.apache.jena.ext.com.google.common.collect.Iterators.concat; +import static org.apache.jena.graph.Node.ANY; +import static org.apache.jena.query.ReadWrite.READ; +import static org.apache.jena.sparql.core.Quad.defaultGraphIRI; +import static org.apache.jena.sparql.util.graph.GraphUtils.triples2quads; + +import java.util.Iterator; + +import org.apache.jena.atlas.lib.Pair; +import org.apache.jena.graph.Graph; +import org.apache.jena.graph.Node; +import org.apache.jena.graph.compose.MultiUnion; +import org.apache.jena.query.ReadWrite; +import org.apache.jena.shared.Lock; +import org.apache.jena.sparql.core.DatasetGraph; +import org.apache.jena.sparql.core.Quad; + +public abstract class ViewDatasetGraph extends Pair.OfSameType<DatasetGraph> implements DatasetGraph { + --- End diff -- Oh, cool. Yes, the `View`ishness is really different than the `Pair`ishness. It's easy to imagine a view that isn't a pair or a pair that is more than a view. I'll go with `DyadicDatasetGraph`, since we already have, as you say, `Dyadic`.
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