mosesdecoder/contrib/other-builds/moses2/LM/LanguageModel.h
2016-01-18 15:37:04 +00:00

97 lines
2.2 KiB
C++

/*
* LanguageModel.h
*
* Created on: 29 Oct 2015
* Author: hieu
*/
#ifndef LANGUAGEMODEL_H_
#define LANGUAGEMODEL_H_
#include "../FF/StatefulFeatureFunction.h"
#include "../TypeDef.h"
#include "../MorphoTrie/MorphTrie.h"
#include "../legacy/Factor.h"
#include "../legacy/Util2.h"
namespace Moses2
{
////////////////////////////////////////////////////////////////////////////////////////
struct LMScores
{
LMScores()
{}
LMScores(const LMScores &copy)
:prob(copy.prob)
,backoff(copy.backoff)
{}
LMScores(float inProb, float inBackoff)
:prob(inProb)
,backoff(inBackoff)
{}
float prob, backoff;
};
inline std::ostream& operator<<(std::ostream &out, const LMScores &obj)
{
out << "(" << obj.prob << "," << obj.backoff << ")" << std::flush;
return out;
}
////////////////////////////////////////////////////////////////////////////////////////
class LanguageModel : public StatefulFeatureFunction
{
public:
LanguageModel(size_t startInd, const std::string &line);
virtual ~LanguageModel();
virtual void Load(System &system);
virtual void SetParameter(const std::string& key, const std::string& value);
virtual FFState* BlankState(MemPool &pool) const;
virtual void EmptyHypothesisState(FFState &state,
const Manager &mgr,
const InputType &input,
const Hypothesis &hypo) const;
virtual void
EvaluateInIsolation(MemPool &pool,
const System &system,
const Phrase &source,
const TargetPhrase &targetPhrase,
Scores &scores,
SCORE *estimatedScore) const;
virtual void EvaluateWhenApplied(const Manager &mgr,
const Hypothesis &hypo,
const FFState &prevState,
Scores &scores,
FFState &state) const;
protected:
std::string m_path;
FactorType m_factorType;
size_t m_order;
MorphTrie<const Factor*, LMScores> m_root;
SCORE m_oov;
const Factor *m_bos;
const Factor *m_eos;
void ShiftOrPush(std::vector<const Factor*> &context, const Factor *factor) const;
std::pair<SCORE, void*> Score(const std::vector<const Factor*> &context) const;
SCORE BackoffScore(const std::vector<const Factor*> &context) const;
void DebugContext(const std::vector<const Factor*> &context) const;
};
}
#endif /* LANGUAGEMODEL_H_ */