/*
 * 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 edu.stanford.futuredata.macrobase.sql.tree;

import java.util.Optional;

public class NullLiteral extends Literal {

    public NullLiteral() {
        super(Optional.empty());
    }

    public NullLiteral(NodeLocation location) {
        super(Optional.of(location));
    }

    @Override
    public <R, C> R accept(AstVisitor<R, C> visitor, C context) {
        return visitor.visitNullLiteral(this, context);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        return o != null && getClass() == o.getClass();
    }

    @Override
    public int hashCode() {
        return 0;
    }
}
