-----------------------------------------------------------------------------
-- |
-- Module      :  Data.Function
-- Copyright   :  (c) 2020-2021 EMQ Technologies Co., Ltd.
-- License     :  BSD-style (see the LICENSE file)
--
-- Maintainer  :  Feng Lee, feng@emqx.io
--                Yang M, yangm@emqx.io
-- Stability   :  experimental
-- Portability :  portable
--
-- The Function data type.
--
-----------------------------------------------------------------------------
module Data.Function
  ( compose , (<<<)
  , composeFlipped , (>>>)
  , flip, const
  , apply, ($)
  , pipeline, (|>)
  , identity
  , error
  ) where

compose :: forall a b c. (b -> c) -> (a -> b) -> (a -> c)
compose f g = \x -> f (g x)

infixr 9 compose as <<<

composeFlipped :: forall a b c. (a -> b) -> (b -> c) -> (a -> c)
composeFlipped f g = compose g f

infixr 9 composeFlipped as >>>

flip :: forall a b c. (a -> b -> c) -> b -> a -> c
flip f b a = f a b

const :: forall a b. a -> b -> a
const a _ = a

apply :: forall a b. (a -> b) -> a -> b
apply f x = f x

infixr 0 apply as $

pipeline :: forall a b. a -> (a -> b) -> b
pipeline x f = f x

infixl 9 apply as |>

identity :: forall a. a -> a
identity x = x

foreign import error :: forall a. String -> a