user/super/com/google/gwt/emul/java/util/Comparators.java

/*
 * Copyright 2007 Google Inc.
 * 
 * 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 java.util;

class Comparators {
  /*
   * This is a utility class that provides a default Comparator.  Instead of
   * having a directly accessible field, a function is used in anticipation of
   * generics support.  This class exists so Arrays and Collections can share
   * the natural comparator without having to know internals of each other.
   */
  
  /**
   * Compares two Objects according to their <i>natural ordering</i>.
   * @see java.lang.Comparable
   */
  private static final Comparator NATURAL = new Comparator() {
    public int compare(Object o1, Object o2) {
      return ((Comparable) o1).compareTo(o2);
    }
  };

  /**
   * Returns the natural Comparator.
   * TODO: generics support
   *  
   * @return the natural Comparator
   */
  public static /*<T>*/ Comparator/*<T>*/ natural() {
    /*
     * Code for generics support is commented.  Example calling code, which
     * should be moved into the Javadoc comment when generics are added:
     *   <code>Comparator&lt;String&gt; = Comparators.natural();</code>
     */
    return /*(Comparator<T>)*/ NATURAL;
  }
}