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fradrive-old/src/Data/Universe/Instances/Reverse/WithIndex.hs

21 lines
526 B
Haskell

{-# OPTIONS_GHC -fno-warn-orphans #-}
module Data.Universe.Instances.Reverse.WithIndex
(
) where
import ClassyPrelude
import Data.Universe
import Control.Lens.Indexed
import Data.Universe.Instances.Reverse ()
import qualified Data.Map as Map
instance Finite a => FoldableWithIndex a ((->) a) where
ifoldMap f g = fold [ f x (g x) | x <- universeF ]
instance (Ord a, Finite a) => TraversableWithIndex a ((->) a) where
itraverse f g = (Map.!) . Map.fromList <$> sequenceA [ (x, ) <$> f x (g x) | x <- universeF ]