/*
* 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.data.DataType;
import org.apache.pig.impl.logicalLayer.FrontendException;
import org.apache.pig.newplan.Operator;
import org.apache.pig.newplan.OperatorPlan;
import org.apache.pig.newplan.PlanVisitor;
import org.apache.pig.newplan.logical.relational.LogicalSchema;
import org.apache.pig.parser.SourceLocation;
/**
* Equality test expression.
*/
public class EqualExpression extends BinaryExpression {
/**
* Will add this operator to the plan and connect it to the
* left and right hand side operators.
* @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 EqualExpression(OperatorPlan plan,
LogicalExpression lhs,
LogicalExpression rhs) {
super("Equal", plan, lhs, rhs);
}
/**
* @link org.apache.pig.newplan.Operator#accept(org.apache.pig.newplan.PlanVisitor)
*/
@Override
public void accept(PlanVisitor v) throws FrontendException {
if (!(v instanceof LogicalExpressionVisitor)) {
throw new FrontendException("Expected LogicalExpressionVisitor", 2222);
}
((LogicalExpressionVisitor)v).visit(this);
}
@Override
public boolean isEqual(Operator other) throws FrontendException {
if (other != null && other instanceof EqualExpression) {
EqualExpression eo = (EqualExpression)other;
return eo.getLhs().isEqual(
getLhs()) &&
eo.getRhs().isEqual(getRhs());
} else {
return false;
}
}
@Override
public LogicalSchema.LogicalFieldSchema getFieldSchema() throws FrontendException {
if (fieldSchema!=null)
return fieldSchema;
fieldSchema = new LogicalSchema.LogicalFieldSchema(null, null, DataType.BOOLEAN);
uidOnlyFieldSchema = fieldSchema.mergeUid(uidOnlyFieldSchema);
return fieldSchema;
}
@Override
public LogicalExpression deepCopy(LogicalExpressionPlan lgExpPlan) throws FrontendException {
LogicalExpression copy = new EqualExpression(
lgExpPlan,
this.getLhs().deepCopy(lgExpPlan),
this.getRhs().deepCopy(lgExpPlan));
copy.setLocation( new SourceLocation( location ) );
return copy;
}
}