1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
// -*- mode: c++; indent-tabs-mode: nil; tab-width:2 -*-
/***********************************************************************
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();
Manager const& manager() const {
UTIL_THROW_IF2(m_path.size() == 0, "zero-length trellis path");
return m_path[0]->GetManager();
}
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 GetFutureScore() 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()
Range 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 Range &sourceRange = edge->GetCurrSourceWordsRange();
out << edge->GetId() << " " << sourceRange.GetStartPos() << "-" << sourceRange.GetEndPos() << ", ";
}
// scores
out << " total=" << path.GetFutureScore()
<< " " << path.GetScoreBreakdown()
<< std::endl;
return out;
}
}
|
