def swap_tree_given_left(left_tree: nltk.Tree,
displacement: List[int],
new_words=List[str]):
"""Swap left node with right node within a parent node."""
nodes = [left_tree]
right_tree = left_tree.right_sibling()
parent_tree = left_tree.parent()
# Get all tree pointer
for disp in displacement:
# disp = -1 indicates that is a new word, skip
if disp == -1:
continue
nodes.append(right_tree)
right_tree = right_tree.right_sibling()
if right_tree == None:
break
# Remove all siblings and left-most self
for node in nodes:
parent_tree.remove(node)
# Append with new displacement
for disp in displacement:
# disp = -1 indicates that is a new word
if disp == -1:
new_word = PTree('NEW', [new_words.pop(0)])
parent_tree.append(new_word)
else:
parent_tree.append(nodes[disp])
return parent_tree
def build_grammar_str_from_left_most(tree: nltk.Tree):
left_pt = tree.left_sibling()
right_pt = tree.right_sibling()
parent_pt = tree.parent()
grammar_str = None
if parent_pt != None:
grammar_str = f"{parent_pt.label()} -> {tree.label()}"
# Build grammar from leftmost node in the subtree
if left_pt == None and right_pt != None:
while right_pt != None:
grammar_str += f" {right_pt.label()}"
right_pt = right_pt.right_sibling()
return grammar_str
def swap_tree_given_left(left_tree: nltk.Tree, displacement: list):
"""
swap left node with right node within a parent node
"""
nodes = [left_tree]
right_tree = left_tree.right_sibling()
parent_tree = left_tree.parent()
# Get all tree pointer
for i in range(len(displacement) - 1):
nodes.append(right_tree)
# Remove all siblings and left-most self
for node in nodes:
parent_tree.remove(node)
# Append with new displacement
for disp in displacement:
parent_tree.append(nodes[disp])
return parent_tree
