Python回调函数的内联

我们正在编写使用回调函数的代码，但是担心小型函数在代码中大肆泛滥，程序的控制流会因此而失控。我们希望能有某种方法使代码看起来更像一般的过程式步骤。我们可以通过生成器和协程将回调函数内联到一个函数中。

具体代码如下：

def apply_async(function, val, *, callback):
    # Compute the result
    result = function(*val)

    #Invoke the callback with the result
    callback(result)


from queue import Queue
from functools import wraps

class Async:

    def __init__(self, function, args):
        self.function = function
        self.args = args

def in_lined_async(function):
    @wraps(function)
    def wrapper(*args):
        f = function(*args)
        result_queue = Queue()
        result_queue.put(None)
        while True:
            result = result_queue.get()
            try:
                a = f.send(result)
                apply_async(a.function, a.args, callback=result_queue.put)
            except StopIteration:
                break
    return wrapper


def add(x, y):return x+y


@in_lined_async
def test():
    r = yield Async(add, (2, 3))
    print(r)
    r = yield Async(add, ("Hello ", "World"))
    print(r)
    for n in range(5):
        r = yield Async(add, (n, n))
        print(r)
    print("Goodbye")