groovy-core/src/main/groovy/util/ClosureComparator.java

/*
 * Copyright 2003-2007 the original author or authors.
 *
 * 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 groovy.util;

import groovy.lang.Closure;
import java.util.Comparator;
import org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation;

/**
 * A Comparator which uses a closure to compare 2 values being equal
 * 
 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
 * @version $Revision$
 */
public class ClosureComparator implements Comparator {

    Closure closure;

    public ClosureComparator(Closure closure) {
        this.closure = closure;
    }

    public int compare(Object object1, Object object2) {
        Object value = closure.call(new Object[] {object1, object2});
        return DefaultTypeTransformation.intUnbox(value);
    }
}