小编use*_*365的帖子

我有一个类型级别的数字

data Z   deriving Typeable
data S n deriving Typeable

和n-ary函数(来自固定向量包的代码)

-- | Type family for n-ary functions.
type family   Fn n a b
type instance Fn Z     a b = b
type instance Fn (S n) a b = a -> Fn n a b

-- | Newtype wrapper which is used to make 'Fn' injective. It's also a
--   reader monad.
newtype Fun n a b = Fun { unFun :: Fn n a b }

我需要像这样的功能

uncurryN …