def pennconverter_find_heads(tree, head_map=None):
if head_map is None:
head_map = {}
tree = treebanks.remove_coindexation(tree, False)
for subtree in tree.subtrees:
pennconverter_find_heads(subtree, head_map)
if log: print "Head for", tree.span, tree.label
# A word is it's own head
if tree.word is not None:
head = (tree.span, tree.word, tree.label)
add_head(head_map, tree, head)
return head_map
# First handle conjunctions
coord = pennconverter_is_coord(tree)
if coord:
if not add_if_match(tree, {'CC', 'CONJP'}, head_map, True):
if not add_if_match(tree, {',', ':'}, head_map, True):
add_head(head_map, tree, get_head(head_map, tree.subtrees[-1]))
return head_map
# If the label for this node is not in the table we are either at the bottom,
# at an NP, or have an error
base_label = treebanks.split_label_type_and_function(tree.label)[0]
if base_label not in pennconverter_mapping_table:
if base_label in ['NP', 'NML']:
collins_NP(tree, head_map)
elif base_label in ['PP', 'WHPP']:
pennconverter_PP(tree, head_map)
else:
add_head(head_map, tree, get_head(head_map, tree.subtrees[-1]))
return head_map
# Look through and take the first/last occurrence that matches
info = pennconverter_mapping_table[base_label]
for label in info[1]:
for i in xrange(len(tree.subtrees)):
if info[0] == 'right':
i = len(tree.subtrees) - i - 1
subtree = tree.subtrees[i]
if isinstance(label, str):
if subtree.label == label:
add_head(head_map, tree, get_head(head_map, subtree))
return head_map
else:
if re.match(label, subtree.label) is not None:
add_head(head_map, tree, get_head(head_map, subtree))
return head_map
# Final fallback
if info[0] == 'left':
add_head(head_map, tree, get_head(head_map, tree.subtrees[0]))
else:
add_head(head_map, tree, get_head(head_map, tree.subtrees[-1]))
return head_map
def get_signature(head_map, tree):
tree_repr = (tree.span, tree.label)
if tree_repr in head_map:
return tree_repr
tree_repr = (tree.wordspan, treebanks.remove_coindexation(tree, False).label)
if tree_repr in head_map:
return tree_repr
tree_repr = (tree.wordspan, treebanks.split_label_type_and_function(tree.label)[0])
if tree_repr in head_map:
return tree_repr
return None
def get_head(head_map, tree, amend_for_trace=False):
if not amend_for_trace:
tree_repr = (tree.span, tree.label)
if tree_repr in head_map:
return head_map[tree_repr]
tree_repr = (tree.wordspan, treebanks.remove_coindexation(tree, False).label)
if tree_repr in head_map:
return head_map[tree_repr]
tree_repr = (tree.wordspan, treebanks.split_label_type_and_function(tree.label)[0])
if tree_repr in head_map:
return head_map[tree_repr]
return None
def without_func(label): return treebanks.split_label_type_and_function(label)[0]
