Review

class DisjunctionSumScorer {
  /** @return An explanation for the score of a given document. */
  public Explanation explain(int doc) throws IOException {
    Explanation res = new Explanation();
    Iterator ssi = subScorers.iterator();
    float sumScore = 0.0f;
    int nrMatches = 0;
    while (ssi.hasNext()) {
      Explanation es = ((Scorer) ssi.next()).explain(doc);
      if (es.getValue() > 0.0f) { // indicates match
        sumScore += es.getValue();
        nrMatches++;
      }
      res.addDetail(es);
    }
    if (nrMatchers >= minimumNrMatchers) {
      res.setValue(sumScore);
      res.setDescription("sum over at least " + minimumNrMatchers
                         + " of " + subScorers.size() + ":");
    } else {
      res.setValue(0.0f);
      res.setDescription(nrMatches + " match(es) but at least "
                         + minimumNrMatchers + " of "
                         + subScorers.size() + " needed");
    }
    return res;
  }

}