Bifoldable.hs

{-# LANGUAGE NoImplicitPrelude #-}
{-# OPTIONS_GHC -Wall #-}

module Papa.Bifunctors.Data.Bifoldable (
  biconcat,
  biconcatMap,
) where

import Data.Bifoldable (Bifoldable (bifold, bifoldMap))
import Data.Monoid (Monoid)

{-# INLINE biconcat #-}
-- | Fold a bifunctor containing monoids.
--
-- >>> biconcat ([1,2], [3,4])
-- [1,2,3,4]
-- >>> biconcat ("hello", " world")
-- "hello world"
biconcat ::
  (Bifoldable p, Monoid m) =>
  p m m ->
  m
biconcat =
  bifold

{-# INLINE biconcatMap #-}
-- | Map each side of a bifunctor to a monoid and combine.
--
-- >>> biconcatMap (\x -> [x]) (\x -> [x]) (1, 2)
-- [1,2]
biconcatMap ::
  (Bifoldable p, Monoid m) =>
  (a -> m) ->
  (b -> m) ->
  p a b ->
  m
biconcatMap =
  bifoldMap