def test_lambda(std_env: Environment) -> None:
source = '(lambda (a b) (if (>= a b) a b))'
func = evaluate(parse(source), std_env)
assert func.parms == ['a', 'b']
assert func.body == [['if', ['>=', 'a', 'b'], 'a', 'b']]
assert func.env is std_env
assert func(1, 2) == 2
assert func(3, 2) == 3
def test_invocation_user_procedure(std_env: Environment) -> None:
source = """
(begin
(define max (lambda (a b) (if (>= a b) a b)))
(max 22 11)
)
"""
got = evaluate(parse(source), std_env)
assert got == 22
def test_begin(std_env: Environment) -> None:
source = """
(begin
(define x (* 2 3))
(* x 7)
)
"""
got = evaluate(parse(source), std_env)
assert got == 42
def test_define_function(std_env: Environment) -> None:
source = '(define (max a b) (if (>= a b) a b))'
got = evaluate(parse(source), std_env)
assert got is None
max_fn = std_env['max']
assert max_fn.parms == ['a', 'b']
assert max_fn.body == [['if', ['>=', 'a', 'b'], 'a', 'b']]
assert max_fn.env is std_env
assert max_fn(1, 2) == 2
assert max_fn(3, 2) == 3
def test_evaluate_variable() -> None:
env: Environment = dict(x=10)
source = 'x'
expected = 10
got = evaluate(parse(source), env)
assert got == expected
def test_evaluate_literal(std_env: Environment) -> None:
source = '3.3'
expected = 3.3
got = evaluate(parse(source), std_env)
assert got == expected
def test_evaluate_variable():
env = dict(x=10)
source = 'x'
expected = 10
got = evaluate(parse(source), env)
assert got == expected
def test_evaluate(source: str, expected: Optional[Expression]) -> None:
got = evaluate(parse(source), global_env_for_first_test)
assert got == expected
def test_invocation_builtin_append(std_env: Environment) -> None:
source = '(append (quote (a b)) (quote (c d)))'
got = evaluate(parse(source), std_env)
assert got == ['a', 'b', 'c', 'd']
def test_invocation_builtin_map(std_env: Environment) -> None:
source = '(map (lambda (x) (* x 2)) (quote (1 2 3))))'
got = evaluate(parse(source), std_env)
assert got == [2, 4, 6]
def test_evaluate_literal(std_env):
source = '3.3'
expected = 3.3
got = evaluate(parse(source), std_env)
assert got == expected
def test_invocation_builtin_car(std_env: Environment) -> None:
source = '(car (quote (11 22 33)))'
got = evaluate(parse(source), std_env)
assert got == 11
def test_evaluate(source, expected):
got = evaluate(parse(source), global_env_for_first_test)
assert got == expected
def test_define(std_env: Environment) -> None:
source = '(define answer (* 6 7))'
got = evaluate(parse(source), std_env)
assert got is None
assert std_env['answer'] == 42
def test_evaluate_if_false(std_env: Environment) -> None:
source = '(if 0 no-such-thing 20)'
expected = 20
got = evaluate(parse(source), std_env)
assert got == expected
def test_evaluate_if_true(std_env: Environment) -> None:
source = '(if 1 10 no-such-thing)'
expected = 10
got = evaluate(parse(source), std_env)
assert got == expected
def test_evaluate_quote(std_env: Environment) -> None:
source = '(quote (1.1 is not 1))'
expected = [1.1, 'is', 'not', 1]
got = evaluate(parse(source), std_env)
assert got == expected
