UnorderedPair.java

package arkref.ext.fig.basic;

/**
 * A generic-typed unordered pair of objects.
 * @author Dan Klein
 */
public class UnorderedPair<F,S> {
  F first;
  S second;

  public F getFirst() {
    return first;
  }

  public S getSecond() {
    return second;
  }

  public boolean equals(Object o) {
    if (this == o) return true;
    if (!(o instanceof UnorderedPair)) return false;

    final UnorderedPair pair = (UnorderedPair) o;

    return (((first == null ? pair.first == null : first.equals(pair.first)) && (second == null ? pair.second == null : second.equals(pair.second))) || ((first == null ? pair.second == null : first.equals(pair.second)) && (second == null ? pair.first == null : second.equals(pair.first))));
  }

  public int hashCode() {
    int firstHashCode = (first == null ? 0 : first.hashCode());
    int secondHashCode = (second == null ? 0 : second.hashCode());
    if (firstHashCode != secondHashCode) {
      return (((firstHashCode & secondHashCode) << 16) ^ ((firstHashCode | secondHashCode)));
    } else {
      return firstHashCode;
    }
  }

  public String toString() {
    String firstString = getFirst().toString();
    String secondString = getSecond().toString();
    if (firstString.compareTo(secondString) > 0) {
      String tempString = firstString;
      firstString = secondString;
      secondString = tempString;
    }
    return "(" + firstString + ", " + secondString + ")";
  }

  public UnorderedPair(F first, S second) {
    this.first = first;
    this.second = second;
  }
}