def test_it_forwards_text_by_one_char_when_sucess(self):
string = 'abc123'
text = Text(string)
parser = Not(String('123'))
parser.parse(text, [])
expected = Text(string)
expected.forward(1)
self.assertEqual(text.position, expected.position)
def test_it_stops_at_first_successful_parser(self):
parser = Or(String('abc'), String('123'))
results = []
parser.parse(Text('abc123'), results)
self.assertListEqual(results, ['abc'])
def test_it_merges_expectations_when_no_successful_parser(self):
parser = Or(String('a'), String('b'))
try:
parser.parse(Text('123'), [])
except ParseError as e:
self.assertEqual(e.expected, '"a" or "b"')
def test_it_parses_as_many_available_matches(self):
parser = Many(String('a'))
results = []
parser.parse(Text('aaabbb'), results)
self.assertEqual(results, ['a', 'a', 'a'])
def test_it_extends_matched_string_when_same_type(self):
parser = String('abc') + String('123')
results = []
parser.parse(Text('abc123'), results)
self.assertListEqual(results, ['abc123'])
def test_it_matches_subsequent_matches_prefixed_by_separator(self):
parser = SeparatedBy(String(','), String('a'))
results = []
parser.parse(Text('a,a,a,'), results)
self.assertEqual(results, ['a', ',', 'a', ',', 'a'])
def test_it_does_not_raise_parse_error_when_fails(self):
parser = Maybe(String('a'))
try:
parser.parse(Text('bbb'), [])
except ParseError:
self.fail('ParseError raised')
def test_it_appends_created_node_to_results_when_successful(self):
name = 'node name'
parser = CreateNode(String('abc'), name)
results = []
parser.parse(Text('abc123'), results)
self.assertListEqual(results, [TerminalNode(name, 'abc')])
def test_it_provides_the_same_text_to_each_parser(self):
text = Text('123')
result = []
parser = Or(Add(String('12'), String('4')), String('123'))
parser.parse(text, result)
self.assertEqual(result, ['123'])
def test_it_does_not_modify_resuls_when_successful(self):
parser = Skip(String('a'))
results = []
try:
parser.parse(Text('aaa'), results)
except ParseError:
self.assertListEqual(results, [])
def test_it_restores_mark_s_position(self):
text = Text('abc123')
fragment = text.lookup(3)
mark = text.mark()
text.forward(3)
text.backtrack(mark)
self.assertEqual(fragment, text.lookup(3))
def test_it_bactracks_when_parser_not_fails(self):
text = Text('abc123')
position = text.position
parser = Not(String('abc'))
try:
parser.parse(text, [])
except ParseError:
pass
self.assertEqual(text.position, position)
def test_it_starts_at_line_1_column_1(self):
text = Text('abc\n123')
self.assertEqual(text.position, Position(1, 1))
def test_it_increment_line_on_each_newline(self):
text = Text('abc\n123\nxyz\n789\n')
text.forward(16)
self.assertEqual(text.position.line, 5)
def test_it_raises_parse_error_when_fails(self):
with self.assertRaises(ParseError):
String('123').parse(Text('abc123'), [])
def test_it_appends_result_to_results_when_success(self):
results = []
String('abc').parse(Text('abc123'), results)
self.assertListEqual(results, ['abc'])
def test_it_raise_parse_error_when_not_a_single_match(self):
parser = Many(String('a'))
with self.assertRaises(ParseError):
parser.parse(Text('bbb'), [])
def test_it_increment_column_when_not_newline(self):
text = Text('abc\n123')
text.forward(3)
self.assertEqual(text.position.column, 4)
def test_it_reset_column_on_newline(self):
text = Text('abc\n123')
text.forward(4)
self.assertEqual(text.position.column, 1)
def test_it_append_first_char_when_sucess(self):
results = []
Not(String('123')).parse(Text('abc123'), results)
self.assertListEqual(results, ['a'])
def test_it_raises_parse_error_when_parser_not_fails(self):
parser = Not(String('abc'))
with self.assertRaises(ParseError):
parser.parse(Text('abc123'), [])
def test_it_forward_text_from_given_length(self):
text = Text('abc123')
text.forward(3)
self.assertEqual(text.lookup(3), '123')
def test_it_raises_parse_error_when_no_successful_parser(self):
parser = Or(String('a'), String('b'))
with self.assertRaises(ParseError):
parser.parse(Text('123'), [])
def test_it_returns_chars_when_chars_left(self):
text = Text('abc123')
fragment = text.lookup(3)
self.assertEqual(fragment, 'abc')