package rebelsky.sorting; 

import java.util.Comparator;

/**
 * A standard comparator for integers.  Note that this is a singleton
 * class - you only ever need one copy of it.  Obtain the one copy
 * with StandardIntegerComparator.comparator.
 *
 * @author Samuel A. Rebelsky
 */
public class StandardIntegerComparator implements Comparator<Integer> {
    /**
     * The one copy.
     */
    public static StandardIntegerComparator comparator = 
            new StandardIntegerComparator();

    /**
     * Build a new comparator.  We make this private to keep the class
     * a singleton.
     */
    private StandardIntegerComparator() {
    } // StandardIntegerComparator()

    @Override
    public int compare(Integer x, Integer y) {
         // The "clever" way to implement this is 
         //   return x-y;
         // Unfortunately, that can lead to overflow or underflow.
	
	// I'd like to use the built-in comparison
	//    return Integer.compare(x,y);
	// Unfortunately, that's not supported in Java 6
	
	// I think this works on most platforms.
	return x.compareTo(y);
    } // compare(Integer, Integer)
} // StandardIntegerComparator