def test_pwr2():
env = stdlib.copy()
evaldef(
"pwr2 = ap ap s ap ap c ap eq 0 1 ap ap b ap mul 2 ap ap b pwr2 ap add -1",
env,
)
assert eval(parse("ap pwr2 8".split()), env) == Number(256)
def test_true_returns_bool():
assert eval(parse("t".split())) == stdlib["t"]
def test_div_returns_integer():
assert eval(parse("ap ap div 10 4".split())) == Number(2)
def test_div_with_two_numbers_returns_result():
assert eval(parse("ap ap div 12 4".split())) == Number(3)
def test_c_combinator():
assert eval(parse("ap ap ap c add 1 2".split())) == Number(3)
def test_lt_with_lhs_greater_than_rhs_returns_false():
assert eval(parse("ap ap lt 2 1".split())) == stdlib["f"]
def test_lt_with_equal_numbers_returns_false():
assert eval(parse("ap ap lt 1 1".split())) == stdlib["f"]
def test_eq_with_numbers():
assert eval(parse("ap ap eq 1 1".split())) == stdlib["t"]
assert eval(parse("ap ap eq 1 2".split())) == stdlib["f"]
def test_inc_with_number_returns_next_number():
assert eval(Apply(Var("inc"), Number(5))) == Number(6)
def test_eval_with_var_looks_up_value():
assert eval(Var("x"), {"x": Number(5)}) == Number(5)
def test_f_combinator():
assert eval(parse("ap ap f 1 5".split())) == Number(5)
assert eval(parse("ap ap f f ap inc 5".split())) == Number(6)
assert eval(parse("ap ap f ap inc 5 t".split())) == stdlib["t"]
def test_eval_with_negative_number_returns_number():
program = Number(-5)
assert eval(program) == program
def test_t_combinator():
assert eval(parse("ap ap t 1 5".split())) == Number(1)
assert eval(parse("ap ap t t ap inc 5".split())) == stdlib["t"]
assert eval(parse("ap ap t ap inc 5 t".split())) == Number(6)
assert eval(parse("ap ap t t i".split())) == stdlib["t"]
def test_b_combinator():
assert eval(parse("ap ap ap b inc dec 5".split())) == Number(5)
def test_false_returns_bool():
assert eval(parse("f".split())) == stdlib["f"]
def test_add_with_two_numbers_returns_result():
# ap (ap add 5) 6
assert eval(Apply(Apply(Var("add"), Number(5)), Number(6))) == Number(11)
def test_eval_with_positive_number_returns_number():
program = Number(5)
assert eval(program) == program
def test_parse_app():
exp = parse(["ap", "ap", "add", "1", "2"])
assert eval(exp) == Number(3)
def test_eq_with_bool():
assert eval(parse("ap ap eq t t".split())) == stdlib["t"]
assert eval(parse("ap ap eq t f".split())) == stdlib["f"]
def test_parse_app2():
# From the video
exp = parse("ap dec ap ap add 1 2".split())
assert eval(exp) == Number(2)
def test_lt_with_lhs_less_than_rhs_returns_true():
assert eval(parse("ap ap lt 1 2".split())) == stdlib["t"]
def test_mul_with_two_numbers_returns_result():
assert eval(parse("ap ap mul 3 4".split())) == Number(12)
def test_neg_with_negative_returns_positive():
assert eval(parse("ap neg -5".split())) == Number(5)
def test_s_combinator():
assert eval(parse("ap ap ap s add inc 1".split())) == Number(3)
assert eval(parse("ap ap ap s mul ap add 1 6".split())) == Number(42)
