Memo List Jun

备忘&开坑记录

Week16

[2017-06-05 16:23:29]

某群的问题：

Haskell prelude 库中带有 a->a 类型签名的函数？

ref:

• Introduction | Hackage
• A Tour of the Haskell Prelude

(伪)标答：

id :: a -> a

完整答案：

-- 无限定
id :: a -> a

-- class Num
abs :: Num a => a -> a
negate :: Num a => a -> a
signum :: Num a => a -> a

recip :: Fractional a => a -> a

-- class Fractional
exp, log, sqrt :: Floating a => a -> a
--- 一些三角函数
sin, cos, tan :: Floating a => a -> a
asin, acos, atan :: Floating a => a -> a
sinh, cosh, tanh :: Floating a => a -> a
asinh, acosh, atanh :: Floating a => a -> a

-- class (RealFrac a, Floating a) => RealFloat a where
significand ::　RealFloat　a => a -> a

-- class Enum
pred :: Enum a => a -> a
succ :: Enum a => a -> a