/* * 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.api.common.functions; import org.apache.flink.annotation.Public; /** * The base interface for all user-defined functions. * * <p>This interface is empty in order to allow extending interfaces to * be SAM (single abstract method) interfaces that can be implemented via Java 8 lambdas.</p> */ @Public public interface Function extends java.io.Serializable { }