def test_to_regex3(self):
""" Tests the transformation to regex """
enfa = EpsilonNFA()
state0 = State(0)
state1 = State(1)
symb_a = Symbol("0")
symb_b = Symbol("1")
enfa.add_start_state(state0)
enfa.add_final_state(state1)
enfa.add_transition(state0, symb_a, state0)
enfa.add_transition(state1, symb_b, state0)
enfa.add_transition(state1, symb_b, state1)
regex = enfa.to_regex()
enfa2 = regex.to_epsilon_nfa()
self.assertFalse(enfa2.accepts([symb_a]))
self.assertFalse(enfa2.accepts([symb_a, symb_a]))
self.assertFalse(enfa2.accepts([symb_a, symb_a, symb_b]))
self.assertFalse(
enfa2.accepts([symb_a, symb_a, symb_b, symb_b, symb_a]))
self.assertFalse(
enfa2.accepts([symb_a, symb_a, symb_b, symb_b, symb_a, symb_b]))
self.assertFalse(enfa2.accepts([symb_b]))
epsilon = Epsilon()
enfa.add_transition(state0, epsilon, state1)
regex = enfa.to_regex()
enfa2 = regex.to_epsilon_nfa()
self.assertTrue(enfa.accepts([]))
self.assertTrue(enfa.accepts([symb_a]))
self.assertTrue(enfa2.accepts([symb_a]))
self.assertTrue(enfa2.accepts([symb_a, symb_a]))
self.assertTrue(enfa2.accepts([symb_a, symb_a, symb_b, symb_b]))
self.assertTrue(
enfa2.accepts([symb_a, symb_a, symb_b, symb_b, symb_a, symb_b]))
self.assertTrue(enfa2.accepts([symb_b]))
self.assertTrue(enfa2.accepts([]))
enfa.remove_transition(state0, symb_a, state0)
regex = enfa.to_regex()
enfa2 = regex.to_epsilon_nfa()
self.assertFalse(enfa2.accepts([symb_a]))
self.assertFalse(enfa2.accepts([symb_a, symb_a]))
self.assertFalse(enfa2.accepts([symb_a, symb_a, symb_b]))
self.assertFalse(
enfa2.accepts([symb_a, symb_a, symb_b, symb_b, symb_a]))
self.assertFalse(
enfa2.accepts([symb_a, symb_a, symb_b, symb_b, symb_a, symb_b]))
self.assertTrue(enfa2.accepts([symb_b]))
self.assertTrue(enfa2.accepts([]))
enfa.remove_transition(state1, symb_b, state1)
regex = enfa.to_regex()
enfa2 = regex.to_epsilon_nfa()
self.assertTrue(enfa2.accepts([symb_b, symb_b]))
enfa.add_transition(state0, symb_a, state0)
regex = enfa.to_regex()
enfa2 = regex.to_epsilon_nfa()
self.assertTrue(enfa2.accepts([symb_a, symb_b]))
def test_minimization(self):
""" Tests the minimization algorithm """
enfa = get_enfa_example0_bis()
symb_a = Symbol("a")
symb_b = Symbol("b")
enfa = enfa.minimize()
self.assertTrue(enfa.is_deterministic())
self.assertEqual(len(enfa.states), 2)
self.assertTrue(enfa.accepts([symb_a, symb_b]))
self.assertTrue(enfa.accepts([symb_a, symb_a, symb_b]))
self.assertTrue(enfa.accepts([symb_b]))
self.assertFalse(enfa.accepts([symb_a]))
enfa = get_example_non_minimal()
enfa = enfa.minimize()
self.assertTrue(enfa.is_deterministic())
self.assertEqual(len(enfa.states), 3)
self.assertTrue(enfa.accepts([symb_a, symb_b]))
self.assertTrue(enfa.accepts([symb_a, symb_a, symb_b]))
self.assertFalse(enfa.accepts([symb_b]))
self.assertFalse(enfa.accepts([symb_a]))
enfa = EpsilonNFA()
enfa = enfa.minimize()
self.assertTrue(enfa.is_deterministic())
self.assertEqual(len(enfa.states), 0)
self.assertFalse(enfa.accepts([]))
def check_correctness(res: EpsilonNFA):
assert res.accepts("ac"), "Word ac should be accepted"
assert not res.accepts("ab"), "Word ab shouldn't be accepted"
assert not res.accepts("abc"), "Word abc shouldn't be accepted"