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/*
* 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.pig.newplan.logical.expression;
import org.apache.pig.impl.logicalLayer.FrontendException;
import org.apache.pig.newplan.OperatorPlan;
/**
* Superclass for all binary expressions
*
*/
public abstract class BinaryExpression extends LogicalExpression {
/**
* Will add this operator to the plan and connect it to the
* left and right hand side operators.
* @param name of the operator
* @param plan plan this operator is part of
* @param lhs expression on its left hand side
* @param rhs expression on its right hand side
*/
public BinaryExpression(String name,
OperatorPlan plan,
LogicalExpression lhs,
LogicalExpression rhs) {
super(name, plan);
plan.add(this);
plan.connect(this, lhs);
plan.connect(this, rhs);
}
/**
* Get the left hand side of this binary expression.
* @return expression on the left hand side
* @throws FrontendException
*/
public LogicalExpression getLhs() throws FrontendException {
return (LogicalExpression)plan.getSuccessors(this).get(0);
}
/**
* Get the right hand side of this binary expression.
* @return expression on the right hand side
* @throws FrontendException
*/
public LogicalExpression getRhs() throws FrontendException {
return (LogicalExpression)plan.getSuccessors(this).get(1);
}
}