mosesdecoder/moses/ChartTranslationOptions.cpp
2015-12-13 22:31:43 +00:00

169 lines
5.6 KiB
C++

/***********************************************************************
Moses - factored phrase-based language decoder
Copyright (C) 2010 Hieu Hoang
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 "ChartTranslationOptions.h"
#include "ChartHypothesis.h"
#include "ChartCellLabel.h"
#include "ChartTranslationOption.h"
#include "InputPath.h"
#include "StaticData.h"
#include "TranslationTask.h"
using namespace std;
namespace Moses
{
ChartTranslationOptions::ChartTranslationOptions(const TargetPhraseCollection &targetPhraseColl,
const StackVec &stackVec,
const Range &range,
float score)
: m_stackVec(stackVec)
, m_wordsRange(&range)
, m_estimateOfBestScore(score)
{
TargetPhraseCollection::const_iterator iter;
for (iter = targetPhraseColl.begin(); iter != targetPhraseColl.end(); ++iter) {
const TargetPhrase *origTP = *iter;
boost::shared_ptr<ChartTranslationOption> ptr(new ChartTranslationOption(*origTP));
m_collection.push_back(ptr);
}
}
ChartTranslationOptions::~ChartTranslationOptions()
{
}
//! functor to compare (chart) hypotheses by (descending) score
class ChartTranslationOptionScoreOrderer
{
public:
bool operator()(const boost::shared_ptr<ChartTranslationOption> &transOptA
, const boost::shared_ptr<ChartTranslationOption> &transOptB) const {
const ScoreComponentCollection &scoresA = transOptA->GetScores();
const ScoreComponentCollection &scoresB = transOptB->GetScores();
return scoresA.GetWeightedScore() > scoresB.GetWeightedScore();
}
};
void ChartTranslationOptions::EvaluateWithSourceContext(const InputType &input, const InputPath &inputPath)
{
SetInputPath(&inputPath);
// if (StaticData::Instance().GetPlaceholderFactor() != NOT_FOUND) {
if (inputPath.ttask->options()->input.placeholder_factor != NOT_FOUND) {
CreateSourceRuleFromInputPath();
}
CollType::iterator iter;
for (iter = m_collection.begin(); iter != m_collection.end(); ++iter) {
ChartTranslationOption &transOpt = **iter;
transOpt.SetInputPath(&inputPath);
transOpt.EvaluateWithSourceContext(input, inputPath, m_stackVec);
}
// get rid of -inf trans opts
size_t numDiscard = 0;
for (size_t i = 0; i < m_collection.size(); ++i) {
ChartTranslationOption *transOpt = m_collection[i].get();
if (transOpt->GetScores().GetWeightedScore() == - std::numeric_limits<float>::infinity()) {
++numDiscard;
} else if (numDiscard) {
m_collection[i - numDiscard] = m_collection[i];
}
}
size_t newSize = m_collection.size() - numDiscard;
m_collection.resize(newSize);
// sort if necessary
const StaticData &staticData = StaticData::Instance();
if (staticData.RequireSortingAfterSourceContext()) {
std::sort(m_collection.begin()
, m_collection.begin() + newSize
, ChartTranslationOptionScoreOrderer());
}
}
void ChartTranslationOptions::SetInputPath(const InputPath *inputPath)
{
CollType::iterator iter;
for (iter = m_collection.begin(); iter != m_collection.end(); ++iter) {
ChartTranslationOption &transOpt = **iter;
transOpt.SetInputPath(inputPath);
}
}
void ChartTranslationOptions::CreateSourceRuleFromInputPath()
{
if (m_collection.size() == 0) {
return;
}
const InputPath *inputPath = m_collection.front()->GetInputPath();
assert(inputPath);
std::vector<const Word*> &ruleSourceFromInputPath = inputPath->AddRuleSourceFromInputPath();
size_t chartCellIndex = 0;
const ChartCellLabel *chartCellLabel = (chartCellIndex < m_stackVec.size()) ? m_stackVec[chartCellIndex] : NULL;
size_t ind = 0;
for (size_t sourcePos = m_wordsRange->GetStartPos(); sourcePos <= m_wordsRange->GetEndPos(); ++sourcePos, ++ind) {
if (chartCellLabel) {
if (sourcePos == chartCellLabel->GetCoverage().GetEndPos()) {
// end of child range. push an empty word to denote non-term
ruleSourceFromInputPath.push_back(NULL);
++chartCellIndex;
chartCellLabel = (chartCellIndex < m_stackVec.size()) ? m_stackVec[chartCellIndex] : NULL;
} else if (sourcePos >= chartCellLabel->GetCoverage().GetStartPos()) {
// in the range of child hypo. do nothing
} else {
// not yet reached child range. add word
ruleSourceFromInputPath.push_back(&inputPath->GetPhrase().GetWord(ind));
}
} else {
// no child in sight. add word
ruleSourceFromInputPath.push_back(&inputPath->GetPhrase().GetWord(ind));
}
}
// save it to each trans opt
CollType::iterator iter;
for (iter = m_collection.begin(); iter != m_collection.end(); ++iter) {
ChartTranslationOption &transOpt = **iter;
transOpt.SetSourceRuleFromInputPath(&ruleSourceFromInputPath);
}
}
std::ostream& operator<<(std::ostream &out, const ChartTranslationOptions &obj)
{
for (size_t i = 0; i < obj.m_collection.size(); ++i) {
const ChartTranslationOption &transOpt = *obj.m_collection[i];
out << transOpt << endl;
}
return out;
}
}