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1. ifoldMapDefault :: (TraversableWithIndex i f, Monoid m) => (i -> a -> m) -> f a -> m

   indexed-traversable	Data.Traversable.WithIndex

   No documentation available.

2. imapAccumL :: TraversableWithIndex i t => (i -> s -> a -> (s, b)) -> s -> t a -> (s, t b)

   indexed-traversable	Data.Traversable.WithIndex

   Generalizes mapAccumL to add access to the index. imapAccumL accumulates state from left to right.

   mapAccumL ≡ imapAccumL . const
   

3. imapAccumR :: TraversableWithIndex i t => (i -> s -> a -> (s, b)) -> s -> t a -> (s, t b)

   indexed-traversable	Data.Traversable.WithIndex

   Generalizes mapAccumR to add access to the index. imapAccumR accumulates state from right to left.

   mapAccumR ≡ imapAccumR . const
   

4. imapDefault :: TraversableWithIndex i f => (i -> a -> b) -> f a -> f b

   indexed-traversable	Data.Traversable.WithIndex

   No documentation available.

5. imapM :: (TraversableWithIndex i t, Monad m) => (i -> a -> m b) -> t a -> m (t b)

   indexed-traversable	Data.Traversable.WithIndex

   Map each element of a structure to a monadic action, evaluate these actions from left to right, and collect the results, with access the index. When you don't need access to the index mapM is more liberal in what it can accept.

   mapM ≡ imapM . const
   

6. foldByKeyHashMap :: (Hashable k, Eq k) => Fold a b -> Fold (k, a) (HashMap k b)

   foldl	Control.Foldl

   Given a Fold, produces a HashMap which applies that fold to each a separated by key k.

   >>> List.sort (HashMap.toList (fold (foldByKeyHashMap Control.Foldl.sum) [("a",1), ("b",2), ("b",20), ("a",10)]))
   [("a",11),("b",22)]
   

7. foldByKeyMap :: Ord k => Fold a b -> Fold (k, a) (Map k b)

   foldl	Control.Foldl

   Given a Fold, produces a Map which applies that fold to each a separated by key k.

   >>> fold (foldByKeyMap Control.Foldl.sum) [("a",1), ("b",2), ("b",20), ("a",10)]
   fromList [("a",11),("b",22)]
   

8. foldMap :: Monoid w => (a -> w) -> (w -> b) -> Fold a b

   foldl	Control.Foldl

   Convert a "foldMap" to a Fold

9. hashMap :: (Eq a, Hashable a) => Fold (a, b) (HashMap a b)

   foldl	Control.Foldl

   Fold pairs into a hash-map.

10. postmapM :: Monad m => (a -> m r) -> FoldM m x a -> FoldM m x r

    foldl	Control.Foldl

    (postmapM f folder) returns a new FoldM where f is applied to the final value.

    postmapM pure = id
    
    postmapM (f >=> g) = postmapM g . postmapM f
    

    postmapM k (pure r) = lifts (k r)
    

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