universum-0.1.8: src/Semiring.hs

{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE Safe              #-}

module Semiring
       ( Semiring(..)
       , zero
       ) where

import           Data.Monoid

-- | Alias for 'mempty'
zero :: Monoid m => m
zero = mempty

class Monoid m => Semiring m where
  {-# MINIMAL one, (<.>) #-}

  one :: m
  (<.>) :: m -> m -> m