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
|
#pragma once
namespace Moses
{
namespace Syntax
{
namespace F2S
{
template<typename Callback>
RuleMatcherHyperTree<Callback>::RuleMatcherHyperTree(const HyperTree &ruleTrie)
: m_ruleTrie(ruleTrie)
{
}
template<typename Callback>
void RuleMatcherHyperTree<Callback>::EnumerateHyperedges(
const Forest::Vertex &v, Callback &callback)
{
const HyperTree::Node &root = m_ruleTrie.GetRootNode();
HyperPath::NodeSeq nodeSeq(1, v.pvertex.symbol[0]->GetId());
const HyperTree::Node *child = root.GetChild(nodeSeq);
if (!child) {
return;
}
m_hyperedge.head = const_cast<PVertex*>(&v.pvertex);
// Initialize the queue.
MatchItem item;
item.annotatedFNS.fns = FNS(1, &v);
item.trieNode = child;
m_queue.push(item);
while (!m_queue.empty()) {
MatchItem item = m_queue.front();
m_queue.pop();
if (item.trieNode->HasRules()) {
const FNS &fns = item.annotatedFNS.fns;
// Set the output hyperedge's tail.
m_hyperedge.tail.clear();
for (FNS::const_iterator p = fns.begin(); p != fns.end(); ++p) {
const Forest::Vertex *v = *p;
m_hyperedge.tail.push_back(const_cast<PVertex *>(&(v->pvertex)));
}
// Set the output hyperedge label's input weight.
m_hyperedge.label.inputWeight = 0.0f;
for (std::vector<const Forest::Hyperedge *>::const_iterator
p = item.annotatedFNS.fragment.begin();
p != item.annotatedFNS.fragment.end(); ++p) {
m_hyperedge.label.inputWeight += (*p)->weight;
}
// Set the output hyperedge label's translation set pointer.
m_hyperedge.label.translations
= item.trieNode->GetTargetPhraseCollection();
// Pass the output hyperedge to the callback.
callback(m_hyperedge);
}
PropagateNextLexel(item);
}
}
template<typename Callback>
void RuleMatcherHyperTree<Callback>::PropagateNextLexel(const MatchItem &item)
{
std::vector<AnnotatedFNS> tfns;
std::vector<AnnotatedFNS> rfns;
std::vector<AnnotatedFNS> rfns2;
const HyperTree::Node &trieNode = *(item.trieNode);
const HyperTree::Node::Map &map = trieNode.GetMap();
for (HyperTree::Node::Map::const_iterator p = map.begin();
p != map.end(); ++p) {
const HyperPath::NodeSeq &edgeLabel = p->first;
const HyperTree::Node &child = p->second;
const int numSubSeqs = CountCommas(edgeLabel) + 1;
std::size_t pos = 0;
for (int i = 0; i < numSubSeqs; ++i) {
const FNS &fns = item.annotatedFNS.fns;
tfns.clear();
if (edgeLabel[pos] == HyperPath::kEpsilon) {
AnnotatedFNS x;
x.fns = FNS(1, fns[i]);
tfns.push_back(x);
pos += 2;
} else {
const int subSeqLength = SubSeqLength(edgeLabel, pos);
const std::vector<Forest::Hyperedge*> &incoming = fns[i]->incoming;
for (std::vector<Forest::Hyperedge *>::const_iterator q =
incoming.begin(); q != incoming.end(); ++q) {
const Forest::Hyperedge &edge = **q;
if (MatchChildren(edge.tail, edgeLabel, pos, subSeqLength)) {
tfns.resize(tfns.size()+1);
tfns.back().fns.assign(edge.tail.begin(), edge.tail.end());
tfns.back().fragment.push_back(&edge);
}
}
pos += subSeqLength + 1;
}
if (tfns.empty()) {
rfns.clear();
break;
} else if (i == 0) {
rfns.swap(tfns);
} else {
CartesianProduct(rfns, tfns, rfns2);
rfns.swap(rfns2);
}
}
for (typename std::vector<AnnotatedFNS>::const_iterator q = rfns.begin();
q != rfns.end(); ++q) {
MatchItem newItem;
newItem.annotatedFNS.fns = q->fns;
newItem.annotatedFNS.fragment = item.annotatedFNS.fragment;
newItem.annotatedFNS.fragment.insert(newItem.annotatedFNS.fragment.end(),
q->fragment.begin(),
q->fragment.end());
newItem.trieNode = &child;
m_queue.push(newItem);
}
}
}
template<typename Callback>
void RuleMatcherHyperTree<Callback>::CartesianProduct(
const std::vector<AnnotatedFNS> &x,
const std::vector<AnnotatedFNS> &y,
std::vector<AnnotatedFNS> &z)
{
z.clear();
z.reserve(x.size() * y.size());
for (typename std::vector<AnnotatedFNS>::const_iterator p = x.begin();
p != x.end(); ++p) {
const AnnotatedFNS &a = *p;
for (typename std::vector<AnnotatedFNS>::const_iterator q = y.begin();
q != y.end(); ++q) {
const AnnotatedFNS &b = *q;
// Create a new AnnotatedFNS.
z.resize(z.size()+1);
AnnotatedFNS &c = z.back();
// Combine frontier node sequences from a and b.
c.fns.reserve(a.fns.size() + b.fns.size());
c.fns.assign(a.fns.begin(), a.fns.end());
c.fns.insert(c.fns.end(), b.fns.begin(), b.fns.end());
// Combine tree fragments from a and b.
c.fragment.reserve(a.fragment.size() + b.fragment.size());
c.fragment.assign(a.fragment.begin(), a.fragment.end());
c.fragment.insert(c.fragment.end(), b.fragment.begin(), b.fragment.end());
}
}
}
template<typename Callback>
bool RuleMatcherHyperTree<Callback>::MatchChildren(
const std::vector<Forest::Vertex *> &children,
const HyperPath::NodeSeq &edgeLabel,
std::size_t pos,
std::size_t subSeqSize)
{
if (children.size() != subSeqSize) {
return false;
}
for (size_t i = 0; i < subSeqSize; ++i) {
if (edgeLabel[pos+i] != children[i]->pvertex.symbol[0]->GetId()) {
return false;
}
}
return true;
}
template<typename Callback>
int RuleMatcherHyperTree<Callback>::CountCommas(const HyperPath::NodeSeq &seq)
{
int count = 0;
for (std::vector<std::size_t>::const_iterator p = seq.begin();
p != seq.end(); ++p) {
if (*p == HyperPath::kComma) {
++count;
}
}
return count;
}
template<typename Callback>
int RuleMatcherHyperTree<Callback>::SubSeqLength(const HyperPath::NodeSeq &seq,
int pos)
{
int length = 0;
HyperPath::NodeSeq::size_type curpos = pos;
while (curpos != seq.size() && seq[curpos] != HyperPath::kComma) {
++curpos;
++length;
}
return length;
}
} // namespace F2S
} // namespace Syntax
} // namespace Moses
|
