mosesdecoder/moses/DecodeStepTranslation.cpp

// $Id$

/***********************************************************************
Moses - factored phrase-based language decoder
Copyright (C) 2006 University of Edinburgh

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
***********************************************************************/

#include "DecodeStepTranslation.h"
#include "PhraseDictionaryMemory.h"
#include "TranslationOption.h"
#include "TranslationOptionCollection.h"
#include "PartialTranslOptColl.h"
#include "FactorCollection.h"

namespace Moses
{
DecodeStepTranslation::DecodeStepTranslation(const PhraseDictionaryFeature* pdf, const DecodeStep* prev)
  : DecodeStep(pdf, prev)
{
}


TranslationOption *DecodeStepTranslation::MergeTranslation(const TranslationOption& oldTO, const TargetPhrase &targetPhrase) const
{
  if (IsFilteringStep()) {
    if (!oldTO.IsCompatible(targetPhrase, m_conflictFactors)) return 0;
  }

  TranslationOption *newTransOpt = new TranslationOption(oldTO);
  newTransOpt->MergeNewFeatures(targetPhrase, targetPhrase.GetScoreBreakdown(), m_newOutputFactors);
  return newTransOpt;
}


void DecodeStepTranslation::Process(const TranslationSystem* system
                                    , const TranslationOption &inputPartialTranslOpt
                                    , const DecodeStep &decodeStep
                                    , PartialTranslOptColl &outputPartialTranslOptColl
                                    , TranslationOptionCollection *toc
                                    , bool adhereTableLimit) const
{
  if (inputPartialTranslOpt.GetTargetPhrase().GetSize() == 0) {
    // word deletion

    outputPartialTranslOptColl.Add(system, new TranslationOption(inputPartialTranslOpt));

    return;
  }

  // normal trans step
  const WordsRange &sourceWordsRange        = inputPartialTranslOpt.GetSourceWordsRange();
  const PhraseDictionary* phraseDictionary  =
    decodeStep.GetPhraseDictionaryFeature()->GetDictionary(); ;
  const size_t currSize = inputPartialTranslOpt.GetTargetPhrase().GetSize();
  const size_t tableLimit = phraseDictionary->GetTableLimit();

  const TargetPhraseCollection *phraseColl=
    phraseDictionary->GetTargetPhraseCollection(toc->GetSource(),sourceWordsRange);

  if (phraseColl != NULL) {
    TargetPhraseCollection::const_iterator iterTargetPhrase, iterEnd;
    iterEnd = (!adhereTableLimit || tableLimit == 0 || phraseColl->GetSize() < tableLimit) ? phraseColl->end() : phraseColl->begin() + tableLimit;

    for (iterTargetPhrase = phraseColl->begin(); iterTargetPhrase != iterEnd; ++iterTargetPhrase) {
      const TargetPhrase& targetPhrase = **iterTargetPhrase;
      // skip if the
      if (targetPhrase.GetSize() != currSize) continue;

      TranslationOption *newTransOpt = MergeTranslation(inputPartialTranslOpt, targetPhrase);
      if (newTransOpt != NULL) {
        outputPartialTranslOptColl.Add(system, newTransOpt );
      }
    }
  } else if (sourceWordsRange.GetNumWordsCovered() == 1) {
    // unknown handler
    //toc->ProcessUnknownWord(sourceWordsRange.GetStartPos(), factorCollection);
  }
}


void DecodeStepTranslation::ProcessInitialTranslation(const TranslationSystem* system
    , const InputType &source
    ,PartialTranslOptColl &outputPartialTranslOptColl
    , size_t startPos, size_t endPos, bool adhereTableLimit) const
{
  const PhraseDictionary* phraseDictionary = GetPhraseDictionaryFeature()->GetDictionary();
  const size_t tableLimit = phraseDictionary->GetTableLimit();

  const WordsRange wordsRange(startPos, endPos);
  const TargetPhraseCollection *phraseColl =	phraseDictionary->GetTargetPhraseCollection(source,wordsRange);

  if (phraseColl != NULL) {
    IFVERBOSE(3) {
      if(StaticData::Instance().GetInputType() == SentenceInput)
        TRACE_ERR("[" << source.GetSubString(wordsRange) << "; " << startPos << "-" << endPos << "]\n");
      else
        TRACE_ERR("[" << startPos << "-" << endPos << "]" << std::endl);
    }

    TargetPhraseCollection::const_iterator iterTargetPhrase, iterEnd;
    iterEnd = (!adhereTableLimit || tableLimit == 0 || phraseColl->GetSize() < tableLimit) ? phraseColl->end() : phraseColl->begin() + tableLimit;

    for (iterTargetPhrase = phraseColl->begin() ; iterTargetPhrase != iterEnd ; ++iterTargetPhrase) {
      const TargetPhrase	&targetPhrase = **iterTargetPhrase;
      outputPartialTranslOptColl.Add (system, new TranslationOption(wordsRange, targetPhrase, source) );

      VERBOSE(3,"\t" << targetPhrase << "\n");
    }
    VERBOSE(3,std::endl);
  }
}

}