void ChartTranslationOptionList::Add(const TargetPhraseCollection &tpc,
                                     const StackVec &stackVec,
                                     const WordsRange &range)
{
  if (tpc.IsEmpty()) {
    return;
  }

  for (size_t i = 0; i < stackVec.size(); ++i) {
    const ChartCellLabel &chartCellLabel = *stackVec[i];
    size_t numHypos = chartCellLabel.GetStack().cube->size();
    if (numHypos == 0) {
      return; // empty stack. These rules can't be used
    }
  }

  float score = ChartTranslationOptions::CalcEstimateOfBestScore(tpc, stackVec);

  // If the rule limit has already been reached then don't add the option
  // unless it is better than at least one existing option.
  if (m_size > m_ruleLimit && score < m_scoreThreshold) {
    return;
  }

  // Add the option to the list.
  if (m_size == m_collection.size()) {
    // m_collection has reached capacity: create a new object.
    m_collection.push_back(new ChartTranslationOptions(tpc, stackVec,
                           range, score));
  } else {
    // Overwrite an unused object.
    *(m_collection[m_size]) = ChartTranslationOptions(tpc, stackVec,
                              range, score);
  }
  ++m_size;

  // If the rule limit hasn't been exceeded then update the threshold.
  if (m_size <= m_ruleLimit) {
    m_scoreThreshold = (score < m_scoreThreshold) ? score : m_scoreThreshold;
  }

  // Prune if bursting
  if (m_size == m_ruleLimit * 2) {
	NTH_ELEMENT4(m_collection.begin(),
                     m_collection.begin() + m_ruleLimit - 1,
                     m_collection.begin() + m_size,
                     ChartTranslationOptionOrderer());
    m_scoreThreshold = m_collection[m_ruleLimit-1]->GetEstimateOfBestScore();
    m_size = m_ruleLimit;
  }
}
void ChartTranslationOptionList::Add(const TargetPhraseCollection &tpc,
                                     const StackVec &stackVec,
                                     const WordsRange &range)
{
  if (tpc.IsEmpty()) {
    return;
  }

  float score = ChartTranslationOptions::CalcEstimateOfBestScore(tpc, stackVec);

  // If the rule limit has already been reached then don't add the option
  // unless it is better than at least one existing option.
  if (m_size > m_ruleLimit && score < m_scoreThreshold) {
    return;
  }

  // Add the option to the list.
  if (m_size == m_collection.size()) {
    // m_collection has reached capacity: create a new object.
    m_collection.push_back(new ChartTranslationOptions(tpc, stackVec,
                                                      range, score));
  } else {
    // Overwrite an unused object.
    *(m_collection[m_size]) = ChartTranslationOptions(tpc, stackVec,
                                                     range, score);
  }
  ++m_size;

  // If the rule limit hasn't been exceeded then update the threshold.
  if (m_size <= m_ruleLimit) {
    m_scoreThreshold = (score < m_scoreThreshold) ? score : m_scoreThreshold;
  }

  // Prune if bursting
  if (m_size == m_ruleLimit * 2) {
    std::nth_element(m_collection.begin(),
                     m_collection.begin() + m_ruleLimit - 1,
                     m_collection.begin() + m_size,
                     ChartTranslationOptionOrderer());
    m_scoreThreshold = m_collection[m_ruleLimit-1]->GetEstimateOfBestScore();
    m_size = m_ruleLimit;
  }
}