    -- |
    -- Module: Data.IntSet.Optics
    -- Description: Optics for working with 'IntSet's.
    --
    -- This module defines optics for constructing and manipulating finite 'IntSet's.
    --
    module Data.IntSet.Optics
      ( members
      , setmapped
      , setOf
      ) where

    import Data.IntSet (IntSet)
    import qualified Data.IntSet as IntSet

    import Optics.Fold
    import Optics.Optic
    import Optics.Setter

    -- | IntSet isn't Foldable, but this 'Fold' can be used to access the members of
    -- an 'IntSet'.
    --
    -- >>> sumOf members $ setOf folded [1,2,3,4]
    -- 10
    members :: Fold IntSet Int
    members :: Fold IntSet Int
    members = (IntSet -> [Int]) -> Fold IntSet Int
    forall (f :: * -> *) s a. Foldable f => (s -> f a) -> Fold s a
    folding IntSet -> [Int]
    IntSet.toAscList
    {-# INLINE members #-}

    -- | This 'Setter' can be used to change the type of a 'IntSet' by mapping the
    -- elements to new values.
    --
    -- Sadly, you can't create a valid 'Optics.Traversal.Traversal' for an 'IntSet',
    -- but you can manipulate it by reading using 'Optics.Fold.folded' and
    -- reindexing it via 'setmapped'.
    --
    -- >>> over setmapped (+1) (IntSet.fromList [1,2,3,4])
    -- fromList [2,3,4,5]
    setmapped :: Setter' IntSet Int
    setmapped :: Setter' IntSet Int
    setmapped = ((Int -> Int) -> IntSet -> IntSet) -> Setter' IntSet Int
    forall a b s t. ((a -> b) -> s -> t) -> Setter s t a b
    sets (Int -> Int) -> IntSet -> IntSet
    IntSet.map
    {-# INLINE setmapped #-}

    -- | Construct an 'IntSet' from a fold.
    --
    -- >>> setOf folded [1,2,3,4]
    -- fromList [1,2,3,4]
    --
    -- >>> setOf (folded % _2) [("hello",1),("world",2),("!!!",3)]
    -- fromList [1,2,3]
    setOf :: Is k A_Fold => Optic' k is s Int -> s -> IntSet
    setOf :: forall k (is :: IxList) s.
    Is k A_Fold =>
    Optic' k is s Int -> s -> IntSet
    setOf Optic' k is s Int
    l = Optic' k is s Int -> (Int -> IntSet) -> s -> IntSet
    forall k m (is :: IxList) s a.
    (Is k A_Fold, Monoid m) =>
    Optic' k is s a -> (a -> m) -> s -> m
    foldMapOf Optic' k is s Int
    l Int -> IntSet
    IntSet.singleton
    {-# INLINE setOf #-}

    -- $setup
    -- >>> import Optics.Core