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// $Id$
/***********************************************************************
Moses - factored phrase-based language decoder
Copyright (C) 2006 University of Edinburgh
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
***********************************************************************/
#pragma once
#include <iostream>
#include <vector>
#include <limits>
#include "Hypothesis.h"
#include "TypeDef.h"
#include <boost/shared_ptr.hpp>
namespace Moses
{
class TrellisPathCollection;
class TrellisPathList;
/** Encapsulate the set of hypotheses/arcs that goes from decoding 1 phrase to all the source phrases
* to reach a final translation. For the best translation, this consist of all hypotheses, for the other
* n-best paths, the node on the path can consist of hypotheses or arcs.
* Used by phrase-based decoding
*/
class TrellisPath
{
friend std::ostream& operator<<(std::ostream&, const TrellisPath&);
friend class Manager;
protected:
std::vector<const Hypothesis *> m_path; //< list of hypotheses/arcs
size_t m_prevEdgeChanged; /**< the last node that was wiggled to create this path
, or NOT_FOUND if this path is the best trans so consist of only hypos
*/
float m_totalScore;
mutable boost::shared_ptr<ScoreComponentCollection> m_scoreBreakdown;
//Used by Manager::LatticeSample()
explicit TrellisPath(const std::vector<const Hypothesis*> edges);
void InitTotalScore();
public:
TrellisPath(); // not implemented
//! create path OF pure hypo
TrellisPath(const Hypothesis *hypo);
/** create path from another path, deviate at edgeIndex by using arc instead,
* which may change other hypo back from there
*/
TrellisPath(const TrellisPath ©, size_t edgeIndex, const Hypothesis *arc);
//! get score for this path throught trellis
inline float GetTotalScore() const {
return m_totalScore;
}
/** list of each hypo/arcs in path. For anything other than the best hypo, it is not possible just to follow the
* m_prevHypo variable in the hypothesis object
*/
inline const std::vector<const Hypothesis *> &GetEdges() const {
return m_path;
}
inline size_t GetSize() const {
return m_path.size();
}
//! create a set of next best paths by wiggling 1 of the node at a time.
void CreateDeviantPaths(TrellisPathCollection &pathColl) const;
//! create a list of next best paths by wiggling 1 of the node at a time.
void CreateDeviantPaths(TrellisPathList &pathColl) const;
const boost::shared_ptr<ScoreComponentCollection> GetScoreBreakdown() const;
//! get target words range of the hypo within n-best trellis. not necessarily the same as hypo.GetCurrTargetWordsRange()
WordsRange GetTargetWordsRange(const Hypothesis &hypo) const;
Phrase GetTargetPhrase() const;
Phrase GetSurfacePhrase() const;
TO_STRING();
};
// friend
inline std::ostream& operator<<(std::ostream& out, const TrellisPath& path)
{
const size_t sizePath = path.m_path.size();
for (int pos = (int) sizePath - 1 ; pos >= 0 ; pos--) {
const Hypothesis *edge = path.m_path[pos];
const WordsRange &sourceRange = edge->GetCurrSourceWordsRange();
out << edge->GetId() << " " << sourceRange.GetStartPos() << "-" << sourceRange.GetEndPos() << ", ";
}
// scores
out << " total=" << path.GetTotalScore()
<< " " << path.GetScoreBreakdown()
<< std::endl;
return out;
}
}
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