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_eclose(self):
""" Test of the epsilon closure """
states = [State(x) for x in range(8)]
epsilon = Epsilon()
symb_a = Symbol("a")
symb_b = Symbol("b")
enfa = EpsilonNFA()
enfa.add_transition(states[1], epsilon, states[2])
enfa.add_transition(states[1], epsilon, states[4])
enfa.add_transition(states[2], epsilon, states[3])
enfa.add_transition(states[3], epsilon, states[6])
enfa.add_transition(states[5], epsilon, states[7])
enfa.add_transition(states[4], symb_a, states[5])
enfa.add_transition(states[5], symb_b, states[6])
self.assertEqual(len(enfa.eclose(states[1])), 5)
self.assertEqual(len(enfa.eclose(states[2])), 3)
self.assertEqual(len(enfa.eclose(states[5])), 2)
self.assertEqual(len(enfa.eclose(states[6])), 1)
self.assertEqual(len(list(enfa._transition_function.get_edges())), 7)
self.assertEqual(enfa.remove_transition(states[1], epsilon, states[4]),
1)
self.assertFalse(enfa.is_deterministic())