相关疑难解决方法(0)

最近我注意到，幽默地liftA可以写成

liftA (<*>) pure

我认为这很整洁，所以开个玩笑，我想我将liftA基于此属性做出新的“定义” ：

f = f (<*>) pure

现在，我曾期望这与liftA从未停止过的事情属于同一类型。但是，它无法编译。

• Occurs check: cannot construct the infinite type:
    t ~ (f (a -> b) -> f a -> f b) -> (a1 -> f1 a1) -> t
• In the expression: f (<*>) pure
  In an equation for ‘f’: f = f (<*>) pure
• Relevant bindings include
    f :: (f (a -> b) -> f a -> f b) -> (a1 …