def test_dfa():
for test_case in parser_test_cases:
parser = RegexParser(dfa=True)
dfa = parser.run(test_case[0])
for success in test_case[1]:
expect(dfa.match_string(success, True),
'"{}" should match "{}"'.format(success, test_case[0]))
for failure in test_case[2]:
expect(not dfa.match_string(failure, True),
'"{}" should not match "{}"'.format(failure, test_case[0]))
assert_expectations()
def test_empty_character_class():
parser = RegexParser()
with pytest.raises(ValueError):
parser.run('[]')
def test_dangling_question():
parser = RegexParser()
with pytest.raises(ValueError):
parser.run('?')
def test_dangling_star():
parser = RegexParser()
with pytest.raises(ValueError):
parser.run('*')
def test_dangling_plus():
parser = RegexParser()
with pytest.raises(ValueError):
parser.run('+')
def test_nfa_intersection_with_dot_no_accepting_state():
nfa_1 = RegexParser().run('a.c')
nfa_2 = RegexParser().run('abd')
intersection_nfa = nfa_1.intersection(nfa_2)
assert not intersection_nfa.has_accepting_states()