def generate_transition(counter, letter, dot):
initial_state = State(counter)
final_state = State(counter)
initial_state.add_transition(letter, final_state)
dot.node(initial_state.id, initial_state.name, shape='circle')
dot.node(final_state.id, final_state.name, shape='circle')
dot.edge(initial_state.id, final_state.id, letter)
return {'initial': initial_state, 'final': final_state}
def test_letter_self_loop_returns_False_when_evaluating_if_finite(self):
state = State('A')
state.add_transition('a', state)
is_finite = state.is_finite()
self.assertEqual(
is_finite, False,
'State with letter self loop does not return False when evaluating if finite'
)
def test_epsilon_self_loop_returns_True_when_evaluating_if_finite(self):
state = State('A')
state.add_transition('_', state)
is_finite = state.is_finite()
self.assertEqual(
is_finite, True,
'State with empty self loop does not return True when evaluating if finite'
)
def test_evaluate_non_empty_word_with_no_transitions_in_state_returns_false(
self):
state = State('A')
evaluation = state.evaluate_word('aaa')
self.assertEqual(
evaluation, False,
'State with no transitions did not return False for a non-empty transitions'
)
def test_is_finite_calls_proper_method(self):
alphabet = 'abc'
initial_state = State('A')
initial_state.is_finite = MagicMock(return_value=True)
is_pda = False
automaton = Automaton(alphabet, initial_state, is_pda)
automaton.is_finite()
initial_state.is_finite.assert_called()
def test_get_all_words_calls_proper_method(self):
alphabet = 'abc'
initial_state = State('A')
initial_state.get_all_words = MagicMock(return_value=[])
is_pda = False
automaton = Automaton(alphabet, initial_state, is_pda)
automaton.get_all_words()
initial_state.get_all_words.assert_called_with([])
def test_pda_evaluate_word_returns_false_when_there_is_no_next_state(self):
state = State('A')
state.pda_determine_next_state = MagicMock(return_value=None)
evaluation = state.pda_evaluate_word('', [])
self.assertEqual(
evaluation, False,
'When there is no next state the pda_evaluate_word does not return False'
)
def test_evaluate_empty_word(self):
state = State('A')
# when state is not final
evaluation = state.evaluate_word('')
self.assertEqual(
evaluation, False,
'Non-final state did not return False for an empty word')
# when state is final
state.is_final = True
evaluation = state.evaluate_word('')
self.assertEqual(evaluation, True,
'Final state did not return True for an empty word')
def test_pda_evaluate_word_with_empty_word(self):
state = State('A')
# empty stack and state is final should return true
state.is_final = True
evaluation = state.pda_evaluate_word('', [])
self.assertEqual(
evaluation, True,
'PDA word evaluate did not return True when stack is empty, state is final and word is empty'
)
# every other case should return false
evaluation = state.pda_evaluate_word('', ['a'])
self.assertEqual(
evaluation, False,
'PDA word evaluate did not return False when stack is not empty, state is final and word is empty'
)
state.is_final = False
evaluation = state.pda_evaluate_word('', [])
self.assertEqual(
evaluation, False,
'PDA word evaluate did not return False when stack is empty, state is not final and word is empty'
)
evaluation = state.pda_evaluate_word('', ['a'])
self.assertEqual(
evaluation, False,
'PDA word evaluate did not return False when stack is not empty, state is not final and word is empty'
)
def parse_states(line, dot):
states = line.split(' ')[1]
sts = {}
for name in states.split(','):
st = State(name)
sts[name] = st
dot.node(st.id, st.name)
return sts
def test_state_with_letter_transition_returns_proper_value(self):
state = State('A')
transition_state = State('B')
transition_state.evaluate_word = MagicMock(return_value=False)
state.add_transition('a', transition_state)
evaluation = state.evaluate_word('abc')
self.assertEqual(
evaluation, False,
'State did not return what letter transition state returns')
def test_state_with_epsilon_transition_returns_proper_value(self):
state = State('A')
transition_state = State('B')
transition_state.evaluate_word = MagicMock(return_value=True)
state.add_transition('_', transition_state)
evaluation = state.evaluate_word('abc')
self.assertEqual(
evaluation, True,
'State did not return what epsilon transition state returns')
def convert_to_dfa(aut, new=None, iteration=None):
if new is None:
initial = State('initial')
epsilon_closure = []
get_epsilon_closure(aut.initial_state, epsilon_closure)
initial.id = str(
reduce(lambda x, y: x + y,
[int(state.id) for state in epsilon_closure]))
new = [(initial, epsilon_closure)]
if contains_final_state(epsilon_closure): initial.is_final = True
if iteration is None: iteration = 0
if iteration < len(new):
sup = {}
for letter in aut.alphabet:
sup[letter] = get_states_for_letter(new[iteration][1], letter)
add_new_states(new, sup)
add_transitions(new, sup, iteration)
return convert_to_dfa(aut, new, iteration + 1)
else:
return new
def test_evaluate_word_calls_proper_method(self):
# Not PDA
alphabet = 'abc'
initial_state = State('A')
initial_state.evaluate_word = MagicMock(return_value=True)
is_pda = False
word = 'test'
automaton = Automaton(alphabet, initial_state, is_pda)
automaton.evaluate_word(word)
initial_state.evaluate_word.assert_called_with(word)
# PDA
is_pda = True
initial_state.pda_evaluate_word = MagicMock(return_value=True)
automaton = Automaton(alphabet, initial_state, is_pda)
automaton.evaluate_word(word)
initial_state.pda_evaluate_word.assert_called_with(word, [])
def test_pda_evaluate_word_returns_proper_result_from_next_state(self):
state1 = State('A')
state2 = State('B')
state1.pda_determine_next_state = MagicMock(return_value=state2)
state2.pda_evaluate_word = MagicMock(return_value=True)
evaluation = state1.pda_evaluate_word('a', [])
self.assertEqual(evaluation, True,
'PDA evaluate word does not return expected result')
def test_init(self):
alphabet = 'abc'
initial_state = State('A')
is_pda = False
automaton = Automaton(alphabet, initial_state, is_pda)
self.assertEqual(automaton.alphabet, alphabet,
"Automaton alphabet is not properly set")
self.assertEqual(automaton.initial_state, initial_state,
"Automaton initial state is not properly set")
self.assertEqual(automaton.is_pda, is_pda,
"Automaton is_pda is not properly set")
def test_no_loops_returns_true(self):
state1 = State('A')
state2 = State('B')
state3 = State('B')
state1.add_transition('_', state2)
state1.add_transition('_', state3)
is_finite = state1.is_finite()
self.assertEqual(
is_finite, True,
'State with no following loops does not return True when evaluating if finite'
)
def test_init(self):
name = 'A'
state = State(name)
self.assertEqual(state.name, name,
'State constructor does not set the name properly')
self.assertEqual(
state.is_final, False,
'State constructor did not set is_final properly (should be False)'
)
self.assertEqual(
state.transitions, {},
'State constructor did not initialize tansitions as an empty object'
)
def add_new_states(new, sup):
for s_arr in sup.values():
if len(s_arr) == 0:
if not contains_state_with_id(new, 0):
new_state = State('0')
new_state.id = '0'
new.append((new_state, s_arr))
else:
epsilon_closure = []
for state in s_arr:
get_epsilon_closure(state, epsilon_closure)
id = reduce(lambda x, y: x + y,
[int(state.id) for state in epsilon_closure])
if not contains_state_with_id(new, id):
new_state = State('')
new_state.id = str(id)
new_state.is_final = contains_final_state(epsilon_closure)
new.append((new_state, epsilon_closure))
def generate_kleene(counter, data, dot):
initial_state = State(counter)
dot.node(initial_state.id, initial_state.name, shape='circle')
initial_state.add_transition('_', data['initial'])
dot.edge(initial_state.id, data['initial'].id, label='ε')
final_state = State(counter)
dot.node(final_state.id, final_state.name, shape='circle')
data['final'].add_transition('_', final_state)
dot.edge(data['final'].id, final_state.id, label='ε')
initial_state.add_transition('_', final_state)
dot.edge(initial_state.id, final_state.id, label='ε')
data['final'].add_transition('_', data['initial'])
dot.edge(data['final'].id, data['initial'].id, label='ε')
return {'initial': initial_state, 'final': final_state}
def test_state_with_emtpy_and_letter_transitions_checks_letter_transitions_if_empty_transitions_return_false(
self):
word = 'aa'
state = State('A')
empty_transitions_state_1 = State('B')
empty_transitions_state_1.evaluate_word = MagicMock(return_value=False)
empty_transitions_state_2 = State('C')
empty_transitions_state_2.evaluate_word = MagicMock(return_value=False)
letter_transition = State('D')
letter_transition.evaluate_word = MagicMock(return_value=True)
state.add_transition('_', empty_transitions_state_1)
state.add_transition('_', empty_transitions_state_2)
state.add_transition('a', letter_transition)
evaluation = state.evaluate_word(word)
empty_transitions_state_1.evaluate_word.assert_called()
empty_transitions_state_2.evaluate_word.assert_called()
letter_transition.evaluate_word.assert_called_with('a')
self.assertEqual(
evaluation, True,
'State with empty and letter transitions does not return the proper value'
)
def test_loop_with_empty_transitions_does_not_create_an_infinite_loop(
self):
state1 = State('A')
state2 = State('B')
state3 = State('B')
state1.add_transition('_', state2)
state2.add_transition('_', state3)
state3.add_transition('_', state1)
evaluation = state1.evaluate_word('abc')
self.assertEqual(
evaluation, False,
'Loop with empty transitions does not act as expected')
def test_pda_determine_next_state_priorty(self):
root = State('A')
child1 = State('B')
child2 = State('C')
child3 = State('D')
child4 = State('E')
root.add_transition('a', (child1, '[x,_]'))
root.add_transition('a', (child2, '[_,x]'))
root.add_transition('_', (child3, '[x,_]'))
root.add_transition('_', (child4, '[_,X]'))
next_state = root.pda_determine_next_state('a', ['x'])
self.assertEqual(next_state, child1)
next_state = root.pda_determine_next_state('a', ['y'])
self.assertEqual(next_state, child2)
next_state = root.pda_determine_next_state('b', ['x'])
self.assertEqual(next_state, child3)
next_state = root.pda_determine_next_state('b', ['y'])
self.assertEqual(next_state, child4)
def test_epsilon_multiple_state_loop_returns_True_when_evaluating_if_finite(
self):
state1 = State('A')
state2 = State('B')
state3 = State('C')
state1.add_transition('_', state2)
state2.add_transition('_', state3)
state3.add_transition('_', state1)
is_finite = state1.is_finite()
self.assertEqual(
is_finite, True,
'State with empty multiple state loop does not return True when evaluating if finite'
)
def test_get_all_words_walks_all_branches(self):
state1 = State('A')
state2 = State('B')
state3 = State('C')
state2.is_final = True
state3.is_final = True
state1.add_transition('a', state2)
state1.add_transition('b', state3)
words = []
state1.get_all_words(words)
self.assertEqual(len(words), 2,
'Number returned words is not as expected')
self.assertIn('a', words,
'Returned words does not contain expected words')
self.assertIn('b', words,
'Returned words does not contain expected words')
def test_letter_multiple_state_loop_returns_False_when_evaluating_if_finite(
self):
state1 = State('A')
state2 = State('B')
state3 = State('C')
state1.add_transition('_', state2)
state2.add_transition('a', state3)
state3.add_transition('_', state1)
is_finite = state1.is_finite()
self.assertEqual(
is_finite, False,
'State with letter multiple state loop does not return False when evaluating if finite'
)