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
|
#!/usr/bin/env python
# Usage: extract-target-trees.py [FILE]
#
# Reads moses-chart's -T output from FILE or standard input and writes trees to
# standard output in Moses' XML tree format.
import re
import sys
class Tree:
def __init__(self, label, children):
self.label = label
self.children = children
def is_leaf(self):
return len(self.children) == 0
class Derivation(list):
def find_root(self):
assert len(self) > 0
root = None
for hypothesis in self:
if hypothesis.span[0] != 0:
continue
if root == None or hypothesis.span[1] > root.span[1]:
root = hypothesis
assert root
return root
def construct_target_tree(self):
map = {}
for hypothesis in self:
map[hypothesis.span] = hypothesis
root = self.find_root()
return self._buildTree(root, map)
def _buildTree(self, root, map):
def escapeLabel(label):
s = label.replace("&", "&")
s = s.replace("<", "<")
s = s.replace(">", ">")
return s
# Build list of NT spans in source order...
nonTermSpans = []
for item in root.sourceSymbolInfo:
span = item[0]
if span in map: # In map iff symbol is NT
nonTermSpans.append(span)
nonTermSpans.sort()
# ... then convert to target order.
alignmentPairs = root.ntAlignments[:]
alignmentPairs.sort()
targetOrderNonTermSpans = {}
for i, pair in enumerate(alignmentPairs):
targetOrderNonTermSpans[pair[1]] = nonTermSpans[i]
children = []
numNonTerms = 0
for i, symbol in enumerate(root.targetRHS):
if i in targetOrderNonTermSpans:
hyp = map[targetOrderNonTermSpans[i]]
children.append(self._buildTree(hyp, map))
numNonTerms += 1
else:
children.append(Tree(escapeLabel(symbol), []))
assert numNonTerms == len(root.ntAlignments)
return Tree(root.targetLHS, children)
class Hypothesis:
def __init__(self):
self.sentenceNum = None
self.span = None
self.sourceSymbolInfo = None
self.targetLHS = None
self.targetRHS = None
self.ntAlignments = None
def __str__(self):
return str(self.id) + " " + str(self.component_scores)
def readDerivations(input, lineNum):
prevSentenceNum = None
derivation = Derivation()
for line in input:
lineNum += 1
hypothesis = parseLine(line)
if hypothesis.sentenceNum != prevSentenceNum:
# We've started reading the next derivation...
prevSentenceNum = hypothesis.sentenceNum
if len(derivation):
yield derivation, lineNum
derivation = Derivation()
derivation.append(hypothesis)
if len(derivation):
yield derivation, lineNum
# Extract the hypothesis components and return a Hypothesis object.
def parseLine(s):
pattern = r"Trans Opt (\d+) " + \
r"\[(\d+)\.\.(\d+)\]:" + \
r"((?: \[\d+\.\.\d+\]=\S+ )+):" + \
r" (\S+) ->" + \
r"((?:\S+ )+):" + \
r"((?:\d+-\d+ )*): pC="
regexp = re.compile(pattern)
match = regexp.match(s)
if not match:
sys.stderr.write("%s\n" % s)
assert match
group = match.groups()
hypothesis = Hypothesis()
hypothesis.sentenceNum = int(group[0]) + 1
hypothesis.span = (int(group[1]), int(group[2]))
hypothesis.sourceSymbolInfo = []
for item in group[3].split():
pattern = "\[(\d+)\.\.(\d+)\]=(\S+)"
regexp = re.compile(pattern)
match = regexp.match(item)
assert(match)
start, end, symbol = match.groups()
span = (int(start), int(end))
hypothesis.sourceSymbolInfo.append((span, symbol))
hypothesis.targetLHS = group[4]
hypothesis.targetRHS = group[5].split()
hypothesis.ntAlignments = []
for pair in group[6].split():
match = re.match(r'(\d+)-(\d+)', pair)
assert match
ai = (int(match.group(1)), int(match.group(2)))
hypothesis.ntAlignments.append(ai)
return hypothesis
def tree_to_xml(tree):
if tree.is_leaf():
return tree.label
else:
s = '<tree label="%s"> ' % tree.label
for child in tree.children:
s += tree_to_xml(child)
s += " "
s += '</tree>'
return s
def main():
if len(sys.argv) > 2:
sys.stderr.write("usage: %s [FILE]\n" % sys.argv[0])
sys.exit(1)
if len(sys.argv) == 1 or sys.argv[1] == "-":
input = sys.stdin
else:
input = open(sys.argv[1])
lineNum = 0
for derivation, lineNum in readDerivations(input, lineNum):
try:
tree = derivation.construct_target_tree()
except:
msg = "error processing derivation at line %d\n" % lineNum
sys.stderr.write(msg)
raise
print tree_to_xml(tree)
if __name__ == '__main__':
main()
|
