// Copyright 2003, Trustees of Indiana University
// Please see the license in the file ../LICENSE

// Simple edge class

public class adj_list_edge<Vertex> implements GraphEdge<Vertex> {
  private Vertex source_, target_;

  public adj_list_edge(Vertex s, Vertex t) {
    source_ = s;
    target_ = t;
  }

  public Vertex source() {return source_;}
  public Vertex target() {return target_;}

  public java.lang.String toString() {
    return "edge(" + source_ + " -> " + target_ + ")";
  }

  public int hashCode() {
    return source_.hashCode() + target_.hashCode();
  }

  public boolean equals(java.lang.Object o) {
    adj_list_edge oo = (adj_list_edge)(o);
    if (oo == null) return false;
    return (source_.equals(oo.source()) && target_.equals(oo.target()));
  }
}