def test_make_example_from_disc_oracle():
actions = [
NT('S'),
NT('NP'),
SHIFT,
REDUCE,
NT('VP'),
SHIFT,
NT('NP'),
SHIFT,
REDUCE,
REDUCE,
REDUCE,
]
pos_tags = 'NNP VBZ NNP'.split()
words = 'John loves Mary'.split()
oracle = Oracle(actions, pos_tags, words)
fields = [
('actions', Field()),
('nonterms', Field()),
('pos_tags', Field()),
('words', Field()),
]
example = make_example(oracle, fields)
assert isinstance(example, Example)
assert example.actions == actions
assert example.nonterms == [get_nonterm(a) for a in actions if is_nt(a)]
assert example.pos_tags == pos_tags
assert example.words == words
def to_tree(self) -> Tree:
stack = []
pos_tags = list(reversed(self.pos_tags))
words = list(reversed(self.words))
for a in self.actions:
if is_nt(a):
stack.append(get_nonterm(a))
elif a == REDUCE:
children = []
while stack and isinstance(stack[-1], Tree):
children.append(stack.pop())
if not children or not stack:
raise ValueError(
f'invalid {REDUCE} action, please check if the actions are correct')
parent = stack.pop()
tree = Tree(parent, list(reversed(children)))
stack.append(tree)
else:
tree = Tree(pos_tags.pop(), [words.pop()])
stack.append(tree)
if len(stack) != 1:
raise ValueError('actions do not produce a single parse tree')
return stack[0]
def action2id(self, action):
if action == REDUCE:
return 0
if action == SHIFT:
return 1
return self.nt2id[get_nonterm(action)] + 2
def make_example(oracle: Oracle, fields: List[Tuple[str, Field]]):
nonterms = [get_nonterm(a) for a in oracle.actions if is_nt(a)]
return Example.fromlist(
[oracle.actions, nonterms, oracle.pos_tags, oracle.words], fields)
def test_get_nonterm_of_invalid_action():
with pytest.raises(ValueError) as excinfo:
get_nonterm(SHIFT)
assert f'action {SHIFT} is not an NT action' in str(excinfo.value)
def test_get_nonterm():
action = NT('NP')
assert get_nonterm(action) == 'NP'