Triple.java

package edu.stanford.nlp.util;

import java.io.Serializable;

/**
 * Class representing an ordered triple of objects, possibly typed.
 * Useful when you'd like a method to return three objects, or would like to put
 * triples of objects in a Collection or Map. equals() and hashcode() should
 * work properly.
 *
 * @author Teg Grenager (grenager@stanford.edu)
 */
public class Triple<T1, T2, T3> implements Serializable {

  public T1 first;
  public T2 second;
  public T3 third;

  public Triple(T1 first, T2 second, T3 third) {
    this.first = first;
    this.second = second;
    this.third = third;
  }

  public T1 first() {
    return first;
  }

  public T2 second() {
    return second;
  }

  public T3 third() {
    return third;
  }

  public void setFirst(T1 o) {
    first = o;
  }

  public void setSecond(T2 o) {
    second = o;
  }

  public void setThird(T3 o) {
    third = o;
  }

  @Override
  public boolean equals(Object o) {

    if (this == o) {
      return true;
    }

    if (!(o instanceof Triple)) {
      return false;
    }

    final Triple triple = (Triple) o;

    if (first != null ? !first.equals(triple.first) : triple.first != null) {
      return false;
    }
    if (second != null ? !second.equals(triple.second) : triple.second != null) {
      return false;
    }
    if (third != null ? !third.equals(triple.third) : triple.third != null) {
      return false;
    }

    return true;
  }

  @Override
  public int hashCode() {
    int result;
    result = (first != null ? first.hashCode() : 0);
    result = 29 * result + (second != null ? second.hashCode() : 0);
    result = 29 * result + (third != null ? third.hashCode() : 0);
    return result;
  }

  @Override
  public String toString() {
    return "(" + first + "," + second + "," + third + ")";
  }

}