protolude-0.3.5: src/Protolude/Semiring.hs

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

module Protolude.Semiring
  ( Semiring,
    one,
    (<.>),
    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