src/org/apache/pig/newplan/logical/expression/NotExpression.java

/*
 * 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;

public class NotExpression extends UnaryExpression {

    public NotExpression(OperatorPlan plan, LogicalExpression exp) {
        super("Not", plan, exp);        
    }

    @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 NotExpression) { 
            NotExpression of = (NotExpression)other;
            return getExpression().isEqual( of.getExpression() );
        } 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 NotExpression(
                lgExpPlan,
                this.getExpression().deepCopy(lgExpPlan) );
        copy.setLocation( new SourceLocation( location ) );
        return copy;
    }

}