/** constructor; just initialize the base class */
TranslationOptionCollectionLattice::TranslationOptionCollectionLattice(
const WordLattice &input
, size_t maxNoTransOptPerCoverage, float translationOptionThreshold)
: TranslationOptionCollection(input, maxNoTransOptPerCoverage, translationOptionThreshold)
{
UTIL_THROW_IF2(StaticData::Instance().GetUseLegacyPT(),
"Not for models using the legqacy binary phrase table");
const InputFeature *inputFeature = StaticData::Instance().GetInputFeature();
UTIL_THROW_IF2(inputFeature == NULL,
"Input feature must be specified");
size_t maxPhraseLength = StaticData::Instance().GetMaxPhraseLength();
size_t size = input.GetSize();
// 1-word phrases
for (size_t startPos = 0; startPos < size; ++startPos) {
const std::vector<size_t> &nextNodes = input.GetNextNodes(startPos);
WordsRange range(startPos, startPos);
const NonTerminalSet &labels = input.GetLabelSet(startPos, startPos);
const ConfusionNet::Column &col = input.GetColumn(startPos);
for (size_t i = 0; i < col.size(); ++i) {
const Word &word = col[i].first;
UTIL_THROW_IF2(word.IsEpsilon(), "Epsilon not supported");
Phrase subphrase;
subphrase.AddWord(word);
const ScorePair &scores = col[i].second;
ScorePair *inputScore = new ScorePair(scores);
InputPath *path = new InputPath(subphrase, labels, range, NULL, inputScore);
size_t nextNode = nextNodes[i];
path->SetNextNode(nextNode);
m_inputPathQueue.push_back(path);
}
}
// iteratively extend all paths
for (size_t endPos = 1; endPos < size; ++endPos) {
const std::vector<size_t> &nextNodes = input.GetNextNodes(endPos);
// loop thru every previous paths
size_t numPrevPaths = m_inputPathQueue.size();
for (size_t i = 0; i < numPrevPaths; ++i) {
//for (size_t pathInd = 0; pathInd < prevPaths.size(); ++pathInd) {
const InputPath &prevPath = *m_inputPathQueue[i];
size_t nextNode = prevPath.GetNextNode();
if (prevPath.GetWordsRange().GetEndPos() + nextNode != endPos) {
continue;
}
size_t startPos = prevPath.GetWordsRange().GetStartPos();
if (endPos - startPos + 1 > maxPhraseLength) {
continue;
}
WordsRange range(startPos, endPos);
const NonTerminalSet &labels = input.GetLabelSet(startPos, endPos);
const Phrase &prevPhrase = prevPath.GetPhrase();
const ScorePair *prevInputScore = prevPath.GetInputScore();
UTIL_THROW_IF2(prevInputScore == NULL,
"Null previous score");
// loop thru every word at this position
const ConfusionNet::Column &col = input.GetColumn(endPos);
for (size_t i = 0; i < col.size(); ++i) {
const Word &word = col[i].first;
Phrase subphrase(prevPhrase);
subphrase.AddWord(word);
const ScorePair &scores = col[i].second;
ScorePair *inputScore = new ScorePair(*prevInputScore);
inputScore->PlusEquals(scores);
InputPath *path = new InputPath(subphrase, labels, range, &prevPath, inputScore);
size_t nextNode = nextNodes[i];
path->SetNextNode(nextNode);
m_inputPathQueue.push_back(path);
} // for (size_t i = 0; i < col.size(); ++i) {
} // for (size_t i = 0; i < numPrevPaths; ++i) {
}
}
