def add_mod(self, seq, mod):
"""Create a tree.{Complement, LookAhead, Neg, Until}"""
modstr = self.value(mod)
if modstr == '~':
seq.parser_tree = parsing.Complement(seq.parser_tree)
elif modstr == '!!':
seq.parser_tree = parsing.LookAhead(seq.parser_tree)
elif modstr == '!':
seq.parser_tree = parsing.Neg(seq.parser_tree)
elif modstr == '->':
seq.parser_tree = parsing.Until(seq.parser_tree)
return True
def test_18_Complement(self):
"""
Basic test for complement ~R
"""
parser = parsing.Parser()
parser.parsed_stream("==")
parseTree = parsing.Seq(
parsing.Call(parsing.Parser.read_char, '='),
parsing.Complement(parsing.Call(parsing.Parser.read_char, '=')))
res = parseTree(parser)
self.assertEqual(res, False, "failed to get the correct final value")
self.assertEqual(parser._stream._cursor._index, 0,
"failed to get the correct index after a lookahead")
parser.parsed_stream("=+")
res = parseTree(parser)
self.assertEqual(res, True, "failed to get the correct final value")
self.assertEqual(parser._stream._cursor._index, 2,
"failed to get the correct index after a lookahead")
def test_it_is_true_when_clause_is_false(self):
clause = mock.Mock(return_value=False)
comp = parsing.Complement(clause)
parser = mock.Mock(**{'read_eof.return_value': False})
self.assertTrue(comp(parser))