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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
|
#include "ConstrainedDecoding.h"
#include "moses/Hypothesis.h"
#include "moses/Manager.h"
#include "moses/ChartHypothesis.h"
#include "moses/ChartManager.h"
#include "moses/StaticData.h"
#include "moses/InputFileStream.h"
#include "moses/Util.h"
#include "util/exception.hh"
using namespace std;
namespace Moses
{
ConstrainedDecodingState::ConstrainedDecodingState(const Hypothesis &hypo)
{
hypo.GetOutputPhrase(m_outputPhrase);
}
ConstrainedDecodingState::ConstrainedDecodingState(const ChartHypothesis &hypo)
{
hypo.GetOutputPhrase(m_outputPhrase);
}
size_t ConstrainedDecodingState::hash() const
{
size_t ret = hash_value(m_outputPhrase);
return ret;
}
bool ConstrainedDecodingState::operator==(const FFState& other) const
{
const ConstrainedDecodingState &otherFF = static_cast<const ConstrainedDecodingState&>(other);
bool ret = m_outputPhrase == otherFF.m_outputPhrase;
return ret;
}
//////////////////////////////////////////////////////////////////
ConstrainedDecoding::ConstrainedDecoding(const std::string &line)
:StatefulFeatureFunction(1, line)
,m_maxUnknowns(0)
,m_negate(false)
,m_soft(false)
{
m_tuneable = false;
ReadParameters();
}
void ConstrainedDecoding::Load(AllOptions const& opts)
{
const StaticData &staticData = StaticData::Instance();
bool addBeginEndWord
= ((opts.search.algo == CYKPlus) || (opts.search.algo == ChartIncremental));
for(size_t i = 0; i < m_paths.size(); ++i) {
InputFileStream constraintFile(m_paths[i]);
std::string line;
long sentenceID = staticData.GetStartTranslationId() - 1;
while (getline(constraintFile, line)) {
vector<string> vecStr = Tokenize(line, "\t");
Phrase phrase(0);
if (vecStr.size() == 1) {
sentenceID++;
phrase.CreateFromString(Output, opts.output.factor_order, vecStr[0], NULL);
} else if (vecStr.size() == 2) {
sentenceID = Scan<long>(vecStr[0]);
phrase.CreateFromString(Output, opts.output.factor_order, vecStr[1], NULL);
} else {
UTIL_THROW(util::Exception, "Reference file not loaded");
}
if (addBeginEndWord) {
phrase.InitStartEndWord();
}
m_constraints[sentenceID].push_back(phrase);
}
}
}
std::vector<float> ConstrainedDecoding::DefaultWeights() const
{
UTIL_THROW_IF2(m_numScoreComponents != 1,
"ConstrainedDecoding must only have 1 score");
vector<float> ret(1, 1);
return ret;
}
template <class H, class M>
const std::vector<Phrase> *GetConstraint(const std::map<long,std::vector<Phrase> > &constraints, const H &hypo)
{
const M &mgr = hypo.GetManager();
const InputType &input = mgr.GetSource();
long id = input.GetTranslationId();
map<long,std::vector<Phrase> >::const_iterator iter;
iter = constraints.find(id);
if (iter == constraints.end()) {
UTIL_THROW(util::Exception, "Couldn't find reference " << id);
return NULL;
} else {
return &iter->second;
}
}
FFState* ConstrainedDecoding::EvaluateWhenApplied(
const Hypothesis& hypo,
const FFState* prev_state,
ScoreComponentCollection* accumulator) const
{
const std::vector<Phrase> *ref = GetConstraint<Hypothesis, Manager>(m_constraints, hypo);
assert(ref);
ConstrainedDecodingState *ret = new ConstrainedDecodingState(hypo);
const Phrase &outputPhrase = ret->GetPhrase();
size_t searchPos = NOT_FOUND;
size_t i = 0;
size_t size = 0;
while(searchPos == NOT_FOUND && i < ref->size()) {
searchPos = (*ref)[i].Find(outputPhrase, m_maxUnknowns);
size = (*ref)[i].GetSize();
i++;
}
float score;
if (hypo.IsSourceCompleted()) {
// translated entire sentence.
bool match = (searchPos == 0) && (size == outputPhrase.GetSize());
if (!m_negate) {
score = match ? 0 : - ( m_soft ? 1 : std::numeric_limits<float>::infinity());
} else {
score = !match ? 0 : - ( m_soft ? 1 : std::numeric_limits<float>::infinity());
}
} else if (m_negate) {
// keep all derivations
score = 0;
} else {
score = (searchPos != NOT_FOUND) ? 0 : - ( m_soft ? 1 : std::numeric_limits<float>::infinity());
}
accumulator->PlusEquals(this, score);
return ret;
}
FFState* ConstrainedDecoding::EvaluateWhenApplied(
const ChartHypothesis &hypo,
int /* featureID - used to index the state in the previous hypotheses */,
ScoreComponentCollection* accumulator) const
{
const std::vector<Phrase> *ref = GetConstraint<ChartHypothesis, ChartManager>(m_constraints, hypo);
assert(ref);
const ChartManager &mgr = hypo.GetManager();
const Sentence &source = static_cast<const Sentence&>(mgr.GetSource());
ConstrainedDecodingState *ret = new ConstrainedDecodingState(hypo);
const Phrase &outputPhrase = ret->GetPhrase();
size_t searchPos = NOT_FOUND;
size_t i = 0;
size_t size = 0;
while(searchPos == NOT_FOUND && i < ref->size()) {
searchPos = (*ref)[i].Find(outputPhrase, m_maxUnknowns);
size = (*ref)[i].GetSize();
i++;
}
float score;
if (hypo.GetCurrSourceRange().GetStartPos() == 0 &&
hypo.GetCurrSourceRange().GetEndPos() == source.GetSize() - 1) {
// translated entire sentence.
bool match = (searchPos == 0) && (size == outputPhrase.GetSize());
if (!m_negate) {
score = match ? 0 : - ( m_soft ? 1 : std::numeric_limits<float>::infinity());
} else {
score = !match ? 0 : - ( m_soft ? 1 : std::numeric_limits<float>::infinity());
}
} else if (m_negate) {
// keep all derivations
score = 0;
} else {
score = (searchPos != NOT_FOUND) ? 0 : - ( m_soft ? 1 : std::numeric_limits<float>::infinity());
}
accumulator->PlusEquals(this, score);
return ret;
}
void ConstrainedDecoding::SetParameter(const std::string& key, const std::string& value)
{
if (key == "path") {
m_paths = Tokenize(value, ",");
} else if (key == "max-unknowns") {
m_maxUnknowns = Scan<int>(value);
} else if (key == "negate") {
m_negate = Scan<bool>(value);
} else if (key == "soft") {
m_soft = Scan<bool>(value);
} else {
StatefulFeatureFunction::SetParameter(key, value);
}
}
}
|
