mosesdecoder/moses/TargetBigramFeature.cpp

124 lines
3.5 KiB
C++

#include "TargetBigramFeature.h"
#include "Phrase.h"
#include "TargetPhrase.h"
#include "Hypothesis.h"
#include "ScoreComponentCollection.h"
#include "util/string_piece_hash.hh"
using namespace std;
namespace Moses {
int TargetBigramState::Compare(const FFState& other) const {
const TargetBigramState& rhs = dynamic_cast<const TargetBigramState&>(other);
return Word::Compare(m_word,rhs.m_word);
}
TargetBigramFeature::TargetBigramFeature(const std::string &line)
:StatefulFeatureFunction("TargetBigramFeature", 0, line)
{
std::cerr << "Initializing target bigram feature.." << std::endl;
vector<string> tokens = Tokenize(line);
//CHECK(tokens[0] == m_description);
// set factor
m_factorType = Scan<FactorType>(tokens[1]);
FactorCollection& factorCollection = FactorCollection::Instance();
const Factor* bosFactor =
factorCollection.AddFactor(Output,m_factorType,BOS_);
m_bos.SetFactor(m_factorType,bosFactor);
const string &filePath = tokens[2];
Load(filePath);
}
bool TargetBigramFeature::Load(const std::string &filePath)
{
if (filePath == "*") return true; //allow all
ifstream inFile(filePath.c_str());
if (!inFile)
{
return false;
}
std::string line;
m_vocab.insert(BOS_);
m_vocab.insert(BOS_);
while (getline(inFile, line)) {
m_vocab.insert(line);
}
inFile.close();
return true;
}
const FFState* TargetBigramFeature::EmptyHypothesisState(const InputType &/*input*/) const
{
return new TargetBigramState(m_bos);
}
FFState* TargetBigramFeature::Evaluate(const Hypothesis& cur_hypo,
const FFState* prev_state,
ScoreComponentCollection* accumulator) const
{
const TargetBigramState* tbState = dynamic_cast<const TargetBigramState*>(prev_state);
CHECK(tbState);
// current hypothesis target phrase
const Phrase& targetPhrase = cur_hypo.GetCurrTargetPhrase();
if (targetPhrase.GetSize() == 0) {
return new TargetBigramState(*tbState);
}
// extract all bigrams w1 w2 from current hypothesis
for (size_t i = 0; i < targetPhrase.GetSize(); ++i) {
const Factor* f1 = NULL;
if (i == 0) {
f1 = tbState->GetWord().GetFactor(m_factorType);
} else {
f1 = targetPhrase.GetWord(i-1).GetFactor(m_factorType);
}
const Factor* f2 = targetPhrase.GetWord(i).GetFactor(m_factorType);
const StringPiece w1 = f1->GetString();
const StringPiece w2 = f2->GetString();
// skip bigrams if they don't belong to a given restricted vocabulary
if (m_vocab.size() &&
(FindStringPiece(m_vocab, w1) == m_vocab.end() || FindStringPiece(m_vocab, w2) == m_vocab.end())) {
continue;
}
string name(w1.data(), w1.size());
name += ":";
name.append(w2.data(), w2.size());
accumulator->PlusEquals(this,name,1);
}
if (cur_hypo.GetWordsBitmap().IsComplete()) {
const StringPiece w1 = targetPhrase.GetWord(targetPhrase.GetSize()-1).GetFactor(m_factorType)->GetString();
const string& w2 = EOS_;
if (m_vocab.empty() || (FindStringPiece(m_vocab, w1) != m_vocab.end())) {
string name(w1.data(), w1.size());
name += ":";
name += w2;
accumulator->PlusEquals(this,name,1);
}
return NULL;
}
return new TargetBigramState(targetPhrase.GetWord(targetPhrase.GetSize()-1));
}
void TargetBigramFeature::Evaluate(const TargetPhrase &targetPhrase
, ScoreComponentCollection &scoreBreakdown
, ScoreComponentCollection &estimatedFutureScore) const
{
CHECK(false);
}
}