def test_can_create_new_function(self):
# Create a square function (which will be added to the environment)
env = Environment()
square_function = "(defun square(x)(* x x)))"
Evaluator.evaluate(Parser.parse(Tokenizer.tokenize(square_function)), env)
self.assertTrue(env.get("square"))
# Call the square function
call_square_function = "(square 9)"
returned_value = Evaluator.evaluate(Parser.parse(Tokenizer.tokenize(call_square_function)), env)
self.assertEqual(returned_value, 81)
def test_can_parse_function_definition(self):
tokens = ["(", "defun", "square", "(", "x", ")", "(", "*", "x", "x", ")", ")" ]
parse_tree = Parser.parse(tokens)
self.assertEqual(len(parse_tree), 1)
self.assertEqual(type(parse_tree[0]), Procedure)
self.assertEqual("square", parse_tree[0].name)
self.assertEqual(len(parse_tree[0].arguments), 1)
def test_can_parse_simple_tokens(self):
tokens = ["(", "*", "a", "b", ")"]
parse_tree = Parser.parse(tokens)
self.assertEqual(type(parse_tree), list)
self.assertEqual(len(parse_tree), 3)
self.assertEqual(type(parse_tree[0]), Operator)
self.assertEqual(type(parse_tree[1]), Symbol)
self.assertEqual(type(parse_tree[2]), Symbol)
def test_can_parse_nested_expression(self):
tokens = ["(", "+", "2.3", "(", "*", "4.5", "3", ")", ")"]
parse_tree = Parser.parse(tokens)
self.assertEqual(len(parse_tree), 3)
self.assertEqual(type(parse_tree[0]), Operator)
self.assertEqual(type(parse_tree[1]), Number)
self.assertEqual(type(parse_tree[2]), list)
self.assertEqual(len(parse_tree[2]), 3)
self.assertEqual(type(parse_tree[2][0]), Operator)
def test_can_parse_floating_point_numbers(self):
tokens = ["(", "3.14", ")"]
parse_tree = Parser.parse(tokens)
self.assertEqual(len(parse_tree), 1)
self.assertEqual(type(parse_tree[0]), Number)
