Self.java

/* Copyright 2013 The jeo project. All rights reserved.
 *
 * 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 io.jeo.filter;

/**
 * Expression that just returns the value passed into it.
 * 
 * @author Justin Deoliveira, Boundless
 */
public class Self implements Expression {

    @Override
    public Object evaluate(Object obj) {
        return obj;
    }

    @Override
    public <R> R accept(FilterVisitor<R> visitor, Object obj) {
        return visitor.visit(this, obj);
    }

    @Override
    public boolean equals(Object obj) {
        return obj instanceof Self;
    }

    @Override
    public int hashCode() {
        return Self.class.hashCode();
    }
}