CharArrayComparator.java

/*
 * Copyright 2008 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 com.google.gwt.dev.util;

import java.io.Serializable;
import java.util.Comparator;

/**
 * Performs a case-sensitive comparison of char arrays.
 */
public class CharArrayComparator implements Comparator<char[]>, Serializable {

  public static final CharArrayComparator INSTANCE = new CharArrayComparator();

  public int compare(char[] a, char[] b) {
    int ai = 0;
    int bi = 0;

    for (; ai < a.length && bi < b.length; ++ai, ++bi) {
      int c = a[ai] - b[bi];
      if (c != 0) {
        return c;
      }
    }

    if (ai == a.length && bi < b.length) {
      // a is shorter
      return -1;
    }

    if (ai < a.length && bi == b.length) {
      // b is shorter
      return 1;
    }

    // they are equal
    //
    return 0;
  }

}