/*
* Copyright (c) 2013-2015 Josef Hardi <josef.hardi@gmail.com>
*
* Licensed 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 com.obidea.semantika.expression.base;
import com.obidea.semantika.exception.IllegalOperationException;
public class NullValue extends AbstractConstant
{
private static final long serialVersionUID = 629451L;
public NullValue()
{
super(null, "");
}
@Override
public String getName()
{
throw new IllegalOperationException("Operation is not supported"); //$NON-NLS-1$
}
@Override
public String getLexicalValue()
{
return "null";
}
@Override
public int hashCode()
{
final int prime = 31;
int result = 1;
result = prime * result + getLexicalValue().hashCode();
return result;
}
@Override
public boolean equals(Object obj)
{
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final NullValue other = (NullValue) obj;
return getLexicalValue().equals(other.getLexicalValue());
}
@Override
public void accept(ITermVisitor visitor)
{
// NO-OP
}
}