def mul(self):
result = self.unary()
while self.current_token().type == TokenType.MUL or self.current_token(
).type == TokenType.DIV:
op = self.advance()
rh = self.unary()
result = BE(result, op, rh)
return result
def add(self):
result = self.mul()
while self.current_token(
).type == TokenType.PLUS or self.current_token(
).type == TokenType.MINUS:
op = self.advance()
rh = self.mul()
result = BE(result, op, rh)
return result
def test_multiplying_two_numbers(self):
input = tokenize('3 * 45')
expected = BE(3.0, Token(TokenType.MUL, '*'), 45.0)
self.assertEqual(expected, Parser(input).expr())
def test_subtracting_two_numbers(self):
input = tokenize('33 - 5')
expected = BE(33.0, Token(TokenType.MINUS, '-'), 5.0)
self.assertEqual(expected, Parser(input).expr())
def test_adding_numbers(self):
input = tokenize('3 + 45 + 8')
expected = BE(BE(3.0, Token(TokenType.PLUS, '+'), 45.0),
Token(TokenType.PLUS, '+'), 8.0)
self.assertEqual(expected, Parser(input).expr())
def test_correctness_of_sequences_with_parenthesis(self):
input = tokenize('2 * (14 + 8)')
expected = BE(2.0, Token(TokenType.MUL, '*'),
BE(14.0, Token(TokenType.PLUS, '+'), 8.0))
self.assertEqual(expected, Parser(input).expr())
def test_correctness_of_sequences(self):
input = tokenize('3 + 45 * 8')
expected = BE(3.0, Token(TokenType.PLUS, '+'),
BE(45.0, Token(TokenType.MUL, '*'), 8.0))
self.assertEqual(expected, Parser(input).expr())
def test_negative_parenthesis(self):
input = tokenize('-(18/5)')
expected = UE(Token(TokenType.MINUS, '-'),
BE(18.0, Token(TokenType.DIV, '/'), 5.0))
self.assertEqual(expected, Parser(input).expr())
def test_dividing_two_numbers(self):
input = tokenize('30 / 5')
expected = BE(30.0, Token(TokenType.DIV, '/'), 5.0)
self.assertEqual(expected, Parser(input).expr())