def test_do_action_when_not_started(self):
parser = DiscriminativeRnnGrammar(self.word2id, self.pos2id, self.nt2id, self.action_store)
with pytest.raises(RuntimeError):
parser.push_non_terminal('S')
with pytest.raises(RuntimeError):
parser.shift()
with pytest.raises(RuntimeError):
parser.reduce()
def test_finished(self):
words = ['John', 'loves', 'Mary']
pos_tags = ['NNP', 'VBZ', 'NNP']
parser = DiscriminativeRnnGrammar(self.word2id, self.pos2id, self.nt2id, self.action_store)
exp_parse_tree = Tree('S', [Tree('NP', ['John']),
Tree('VP', ['loves', Tree('NP', ['Mary'])])])
parser.initialise_stacks_and_buffers(list(zip(words, pos_tags)))
parser.push_non_terminal('S')
parser.push_non_terminal('NP')
parser.shift()
parser.reduce()
parser.push_non_terminal('VP')
parser.shift()
parser.push_non_terminal('NP')
parser.shift()
parser.reduce()
parser.reduce()
parser.reduce()
assert parser.finished
parse_tree = parser.stack_buffer[-1]
assert parse_tree == exp_parse_tree
with pytest.raises(RuntimeError):
parser()
with pytest.raises(RuntimeError):
parser.push_non_terminal('NP')
with pytest.raises(RuntimeError):
parser.shift()
with pytest.raises(RuntimeError):
parser.reduce()
def test_forward(self):
words = ['John', 'loves', 'Mary']
pos_tags = ['NNP', 'VBZ', 'NNP']
parser = DiscriminativeRnnGrammar(self.word2id, self.pos2id, self.nt2id, self.action_store)
parser.initialise_stacks_and_buffers(list(zip(words, pos_tags)))
parser.push_non_terminal('S')
parser.push_non_terminal('NP')
parser.shift()
parser.reduce()
action_logprobs = parser()
assert isinstance(action_logprobs, Variable)
assert action_logprobs.size() == (len(self.action_store),)
sum_prob = action_logprobs.exp().sum().data[0]
assert 0.999 <= sum_prob <= 1.001
def test_do_illegal_reduce_action(self):
words = ['John', 'loves']
pos_tags = ['NNP', 'VBZ']
parser = DiscriminativeRnnGrammar(self.word2id, self.pos2id, self.nt2id, self.action_store)
# Top of stack is an open nonterminal
parser.initialise_stacks_and_buffers(list(zip(words, pos_tags)))
parser.push_non_terminal('S')
with pytest.raises(IllegalActionError):
parser.reduce()
# Buffer is not empty and REDUCE will finish parsing
parser.initialise_stacks_and_buffers(list(zip(words, pos_tags)))
parser.push_non_terminal('S')
parser.shift()
with pytest.raises(IllegalActionError):
parser.reduce()
def test_do_reduce_action(self):
words = ['John', 'loves', 'Mary']
pos_tags = ['NNP', 'VBZ', 'NNP']
parser = DiscriminativeRnnGrammar(self.word2id, self.pos2id, self.nt2id, self.action_store)
parser.initialise_stacks_and_buffers(list(zip(words, pos_tags)))
parser.push_non_terminal('S')
parser.push_non_terminal('NP')
parser.shift()
prev_input_buffer = parser.input_buffer
parser.reduce()
assert len(parser.stack_buffer) == 2
last = parser.stack_buffer[-1]
assert isinstance(last, Tree)
assert last.label() == 'NP'
assert len(last) == 1
assert last[0] == 'John'
assert parser.input_buffer == prev_input_buffer
assert len(parser.action_history) == 4
assert parser.action_history[-1] == ReduceAction()
assert not parser.finished