def test_call_current_continuation(self): # divide_cps :: Int -> Int -> (String -> Cont r Int) -> Cont r Int def divide_cps(x, y, k): return callCC(lambda ok: callCC(lambda not_ok: not_ok("Divide by zero error") if y is 0 else ok(x / y)) >= (lambda err: k(err))) error = lambda err: Cont(lambda _: self.__set_error_message(err)) self.assertEquals(3, Cont.runCont(divide_cps(10, 3, error), lambda x: x)) Cont.runCont(divide_cps(10, 0, error), lambda x: x) self.assertEquals("Divide by zero error", self.error_message)
def test_desugared_do_notation(self): # do x_squared <- square_cont x # y_squared <- square_cont y # sum_of_squares <- add_cont x_squared y_squared # return sum_of_squares add_cps = lambda x, y: return_(x + y) square_cps = lambda x: return_(x ** 2) pythagoras_cps = lambda x, y: (square_cps(x) >= ((lambda x_squared: square_cps(y) >= ((lambda y_squared: add_cps(x_squared, y_squared) >= (lambda sum_of_squares: return_(sum_of_squares))))))) result = Cont.runCont(pythagoras_cps(3, 4), lambda x: x) self.assertEquals(25, result)
def test_bind(self): square_cps = lambda x: return_(x ** 2) add_three_cps = lambda x: return_(x + 3) result = Cont.runCont(square_cps(4) >= add_three_cps, lambda x: x) self.assertEquals(19, result)
def test_single_value(self): value = 7 cont = return_(value) result = Cont.runCont(cont, lambda x: x) self.assertEquals(value, result)