-----------------------------------------------------------------------------
-- |
-- Module      :  Data.Semiring
-- 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 Semiring typeclass.
--
-----------------------------------------------------------------------------
module Data.Semiring where

class Semiring a where
  add  :: a -> a -> a
  zero :: a
  mul  :: a -> a -> a
  one  :: a

infixl 6 add as +
infixl 7 mul as *

instance Semiring Integer where
  add = addInt
  zero = 0
  mul = mulInt
  one = 1

instance Semiring Float where
  add = addFloat
  zero = 0.0
  mul = mulFloat
  one = 1.0

foreign import addInt :: Integer -> Integer -> Integer
foreign import mulInt :: Integer -> Integer -> Integer
foreign import addFloat :: Float -> Float -> Float
foreign import mulFloat :: Float -> Float -> Float