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#include "PhraseBoundaryFeature.h"
#include "Hypothesis.h"
using namespace std;
namespace Moses {
int PhraseBoundaryState::Compare(const FFState& other) const
{
const PhraseBoundaryState& rhs = dynamic_cast<const PhraseBoundaryState&>(other);
int tgt = Word::Compare(*m_targetWord,*(rhs.m_targetWord));
if (tgt) return tgt;
return Word::Compare(*m_sourceWord,*(rhs.m_sourceWord));
}
PhraseBoundaryFeature::PhraseBoundaryFeature
(const FactorList& sourceFactors, const FactorList& targetFactors) :
StatefulFeatureFunction("pb", ScoreProducer::unlimited), m_sourceFactors(sourceFactors),
m_targetFactors(targetFactors), m_sparseProducerWeight(1)
{
}
string PhraseBoundaryFeature::GetScoreProducerWeightShortName(unsigned) const
{
return "pb";
}
size_t PhraseBoundaryFeature::GetNumInputScores() const
{
return 0;
}
const FFState* PhraseBoundaryFeature::EmptyHypothesisState(const InputType &) const
{
return new PhraseBoundaryState(NULL,NULL);
}
void PhraseBoundaryFeature::AddFeatures(
const Word* leftWord, const Word* rightWord, const FactorList& factors, const string& side,
ScoreComponentCollection* scores) const {
for (size_t i = 0; i < factors.size(); ++i) {
ostringstream name;
name << side << ":";
name << factors[i];
name << ":";
if (leftWord) {
name << leftWord->GetFactor(factors[i])->GetString();
} else {
name << BOS_;
}
name << ":";
if (rightWord) {
name << rightWord->GetFactor(factors[i])->GetString();
} else {
name << EOS_;
}
scores->PlusEquals(this,name.str(),1);
}
}
FFState* PhraseBoundaryFeature::Evaluate
(const Hypothesis& cur_hypo, const FFState* prev_state,
ScoreComponentCollection* scores) const
{
const PhraseBoundaryState* pbState = dynamic_cast<const PhraseBoundaryState*>(prev_state);
const Phrase& targetPhrase = cur_hypo.GetCurrTargetPhrase();
if (targetPhrase.GetSize() == 0) {
return new PhraseBoundaryState(*pbState);
}
const Word* leftTargetWord = pbState->GetTargetWord();
const Word* rightTargetWord = &(targetPhrase.GetWord(0));
AddFeatures(leftTargetWord,rightTargetWord,m_targetFactors,"tgt",scores);
const Phrase* sourcePhrase = cur_hypo.GetSourcePhrase();
const Word* leftSourceWord = pbState->GetSourceWord();
const Word* rightSourceWord = &(sourcePhrase->GetWord(0));
AddFeatures(leftSourceWord,rightSourceWord,m_sourceFactors,"src",scores);
const Word* endSourceWord = &(sourcePhrase->GetWord(sourcePhrase->GetSize()-1));
const Word* endTargetWord = &(targetPhrase.GetWord(targetPhrase.GetSize()-1));
//if end of sentence add EOS
if (cur_hypo.IsSourceCompleted()) {
AddFeatures(endSourceWord,NULL,m_sourceFactors,"src",scores);
AddFeatures(endTargetWord,NULL,m_targetFactors,"tgt",scores);
}
return new PhraseBoundaryState(endSourceWord,endTargetWord);
}
}
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