/** * 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.hadoop.hive.ql.lib; import java.util.Stack; import org.apache.hadoop.hive.ql.parse.SemanticException; /** * Base class for processing operators which is no-op. The specific processors * can register their own context with the dispatcher. */ public interface NodeProcessor { /** * Generic process for all ops that don't have specific implementations. * * @param nd * operator to process * @param procCtx * operator processor context * @param nodeOutputs * A variable argument list of outputs from other nodes in the walk * @return Object to be returned by the process call * @throws SemanticException */ Object process(Node nd, Stack<Node> stack, NodeProcessorCtx procCtx, Object... nodeOutputs) throws SemanticException; }