/*
 * 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.flink.graph;

/**
 * The EdgeDirection is used to select a node's neighborhood
 * by the {@link Graph#groupReduceOnEdges(EdgesFunction, EdgeDirection)},
 * {@link Graph#groupReduceOnEdges(EdgesFunctionWithVertexValue, EdgeDirection)},
 * {@link Graph#groupReduceOnNeighbors(NeighborsFunction, EdgeDirection)},
 * {@link Graph#groupReduceOnNeighbors(NeighborsFunctionWithVertexValue, EdgeDirection)},
 * {@link Graph#reduceOnEdges(ReduceEdgesFunction, EdgeDirection)} and
 * {@link Graph#reduceOnNeighbors(ReduceNeighborsFunction, EdgeDirection)}
 * methods.
 */
public enum EdgeDirection {
	IN,
	OUT,
	ALL
}