HashValue.java

/*
 * (C) Copyright 2005 Arnaud Bailly (arnaud.oqube@gmail.com),
 *     Yves Roos (yroos@lifl.fr) and others.
 *
 * 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 rationals.transformations;

import java.util.Set;

/**
 * A simple class for encapsulating sets s.t. they can be used
 * efficiently in Set or HashMap.
 * 
 * @author nono
 * @version $Id: HashValue.java 2 2006-08-24 14:41:48Z oqube $
 */
public class HashValue<T> {
    
    public final int hash;

    public final Set<T> s;

    public HashValue(Set<T> s) {
        this.s = s;
        this.hash = s.hashCode();
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#equals(java.lang.Object)
     */
    public boolean equals(Object obj) {
    	if (!(obj instanceof HashValue)) return false;
        return ((HashValue<?>) obj).hash == hash;
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#hashCode()
     */
    public int hashCode() {
        return hash;
    }
    
    /* (non-Javadoc)
     * @see java.lang.Object#toString()
     */
    public String toString() {
        return s.toString();
    }
}