def testSimpleExpression(self):
tokens = iter([Identifier('x'), '+', Identifier('y'), EOF()])
parser = Parser(tokens)
parser._advance()
expression = parser._parse_expression()
self.assertIsInstance(expression, Expression)
self.assertIsInstance(expression.lhs, Variable)
self.assertEquals(expression.lhs.identifier.identifier, 'x')
self.assertIsInstance(expression.rhs, Variable)
self.assertEquals(expression.rhs.identifier.identifier, 'y')
self.assertEquals('+', expression.operator)
def testComplexExpression(self):
tokens = iter([Identifier('a'), '+', Identifier('b'), '+', '(',
Identifier('c'), '+', Identifier('d'), ')', '*',
Identifier('e'), '*', Identifier('f'), '+',
Identifier('g'), EOF()])
parser = Parser(tokens)
parser._advance()
expression = parser._parse_expression()
self.assertIsInstance(expression, Expression)
self.assertEquals(expression.lhs.lhs.lhs.identifier.identifier, 'a')
self.assertEquals(expression.lhs.lhs.operator, '+')
self.assertEquals(expression.lhs.lhs.rhs.identifier.identifier, 'b')
self.assertEquals(expression.lhs.operator, '+')
self.assertEquals(expression.operator, '+')
self.assertEquals(expression.lhs.rhs.lhs.lhs.lhs.identifier.identifier, 'c')
self.assertEquals(expression.lhs.rhs.lhs.lhs.operator, '+')
self.assertEquals(expression.lhs.rhs.lhs.lhs.rhs.identifier.identifier, 'd')
self.assertEquals(expression.lhs.rhs.lhs.operator, '*')
self.assertEquals(expression.lhs.rhs.lhs.rhs.identifier.identifier, 'e')
self.assertEquals(expression.lhs.rhs.operator, '*')
self.assertEquals(expression.lhs.rhs.rhs.identifier.identifier, 'f')
self.assertEquals(expression.rhs.identifier.identifier, 'g')
