mosesdecoder/moses/FF/TreeStructureFeature.h
2015-12-11 01:09:22 +00:00

82 lines
2.1 KiB
C++

#pragma once
#include <string>
#include <map>
#include "StatefulFeatureFunction.h"
#include "FFState.h"
#include "moses/Word.h"
#include "InternalTree.h"
namespace Moses
{
typedef int NTLabel;
// mapping from string nonterminal label to int representation.
// allows abstraction if multiple nonterminal strings should map to same label.
struct LabelSet {
public:
std::map<std::string, NTLabel> string_to_label;
};
// class to implement language-specific syntactic constraints.
// the method SyntacticRules is given pointer to ScoreComponentCollection, so it can add sparse features itself.
class SyntaxConstraints
{
public:
virtual void SyntacticRules(TreePointer root, const std::vector<TreePointer> &previous, const FeatureFunction* sp, ScoreComponentCollection* accumulator) = 0;
virtual ~SyntaxConstraints() {};
};
class TreeStructureFeature : public StatefulFeatureFunction
{
SyntaxConstraints* m_constraints;
LabelSet* m_labelset;
bool m_binarized;
Word m_send;
Word m_send_nt;
public:
TreeStructureFeature(const std::string &line)
:StatefulFeatureFunction(0, line)
, m_binarized(false) {
ReadParameters();
std::vector<FactorType> factors;
factors.push_back(0);
m_send.CreateFromString(Output, factors, "</s>", false);
m_send_nt.CreateFromString(Output, factors, "SEND", true);
}
~TreeStructureFeature() {
delete m_constraints;
};
virtual const FFState* EmptyHypothesisState(const InputType &input) const {
return new TreeState(TreePointer());
}
bool IsUseable(const FactorMask &mask) const {
return true;
}
void SetParameter(const std::string& key, const std::string& value);
FFState* EvaluateWhenApplied(
const Hypothesis& cur_hypo,
const FFState* prev_state,
ScoreComponentCollection* accumulator) const {
UTIL_THROW(util::Exception, "Not implemented");
};
FFState* EvaluateWhenApplied(
const ChartHypothesis& /* cur_hypo */,
int /* featureID - used to index the state in the previous hypotheses */,
ScoreComponentCollection* accumulator) const;
void Load(AllOptions::ptr const& opts);
};
}