code: package caevo.sieves;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import caevo.SieveDocument;
  import caevo.SieveDocuments;
  import caevo.SieveSentence;
  import caevo.TextEvent;
  import caevo.tlink.EventEventLink;
  import caevo.tlink.TLink;
  
  /**
   * Implements rule number 64, in the category of "Word Features", from D'Souza &
   * Ng 2013. Reported Accuracy: 217/1306 In English: If e1 and e2 are events, and
   * share the same tense and aspect, e1 BEFORE e2 (where e1 occurs before e2 in
   * the text)
   * 
   * Only considers events within the same sentence
   * 
   * @author cassidy
   */
  
  public class WordFeatures64 implements Sieve {
    public boolean debug = false;
  
    /**
     * The main function. All sieves must have this.
     */
    public List<TLink> annotate(SieveDocument doc, List<TLink> currentTLinks) {
      // The size of the list is the number of sentences in the document.
      // The inner list is the events in textual order.
      List<List<TextEvent>> allEvents = doc.getEventsBySentence();
      // Fill this with our new proposed TLinks.
      List<TLink> proposed = new ArrayList<TLink>();
  
      // Add all pairs of events that satisfy the rule criteria
      List<SieveSentence> sentList = doc.getSentences();
      int sid = 0;
  
      for (SieveSentence sent : sentList) {
        if (debug == true) {
          System.out.println("DEBUG: adding tlinks from " + doc.getDocname()
              + " sentences:\n" + sent.sentence() + "\n" + sent.sentence());
        }
        // Check all event pairs in allEventsSent against rule criteria
        proposed.addAll(allPairsEvents(allEvents.get(sid)));
        sid++;
      }
      if (debug == true) {
        System.out.println("TLINKS: " + proposed);
      }
      return proposed;
    }
  
    private List<TLink> allPairsEvents(List<TextEvent> events) {
      List<TLink> proposed = new ArrayList<TLink>();
      // check all e1, e2 such that e1 precedes e2 in the text
      for (int xx = 0; xx < events.size(); xx++) {
        for (int yy = xx + 1; yy < events.size(); yy++) {
          TextEvent e1 = events.get(xx);
          TextEvent e2 = events.get(yy);
          // Check event pair against rule criteria; add matches to proposed
          if (e1.getTense() == e2.getTense()
              && e2.getAspect() == e2.getAspect()) {
            proposed.add(new EventEventLink(e1.getEiid(), e2.getEiid(),
                TLink.Type.BEFORE));
          }
        }
      }
      if (debug == true) {
        System.out.println("events: " + events);
        System.out.println("created tlinks: " + proposed);
      }
      return proposed;
    }
  
    /**
     * No training. Just rule-based.
     */
    public void train(SieveDocuments trainingInfo) {
      // no training
    }
  
  }
  