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1. mapMaybe :: forall (m :: Type -> Type) a b r . Monad m => (a -> Maybe b) -> Fold m b r -> Fold m a r

   streamly-core	Streamly.Data.Fold

   mapMaybe f fold maps a Maybe returning function f on the input of the fold, filters out Nothing elements, and return the values extracted from Just.

   >>> mapMaybe f = Fold.lmap f . Fold.catMaybes
   
   >>> mapMaybe f = Fold.mapMaybeM (return . f)
   

   >>> f x = if even x then Just x else Nothing
   
   >>> fld = Fold.mapMaybe f Fold.toList
   
   >>> Stream.fold fld (Stream.enumerateFromTo 1 10)
   [2,4,6,8,10]
   

2. mapMaybe :: forall (m :: Type -> Type) a b . Monad m => (a -> Maybe b) -> Stream m a -> Stream m b

   streamly-core	Streamly.Data.Stream

   Map a Maybe returning function to a stream, filter out the Nothing elements, and return a stream of values extracted from Just. Equivalent to:

   >>> mapMaybe f = Stream.catMaybes . fmap f
   

3. mapMaybe :: forall (m :: Type -> Type) a b r . Monad m => (a -> Maybe b) -> Fold m b r -> Fold m a r

   streamly-core	Streamly.Internal.Data.Fold

   mapMaybe f fold maps a Maybe returning function f on the input of the fold, filters out Nothing elements, and return the values extracted from Just.

   >>> mapMaybe f = Fold.lmap f . Fold.catMaybes
   
   >>> mapMaybe f = Fold.mapMaybeM (return . f)
   

   >>> f x = if even x then Just x else Nothing
   
   >>> fld = Fold.mapMaybe f Fold.toList
   
   >>> Stream.fold fld (Stream.enumerateFromTo 1 10)
   [2,4,6,8,10]
   

4. mapMaybe :: forall (m :: Type -> Type) a b . Monad m => (a -> Maybe b) -> Stream m a -> Stream m b

   streamly-core	Streamly.Internal.Data.Stream

   Map a Maybe returning function to a stream, filter out the Nothing elements, and return a stream of values extracted from Just. Equivalent to:

   >>> mapMaybe f = Stream.catMaybes . fmap f
   

5. mapMaybe :: forall a b (m :: Type -> Type) . (a -> Maybe b) -> StreamK m a -> StreamK m b

   streamly-core	Streamly.Internal.Data.StreamK

   No documentation available.

6. mapMaybe :: (Arrow arrow, Functor f) => (a -> Maybe b) -> arrow (f [a]) (f [b])

   synthesizer-midi	Synthesizer.MIDI.CausalIO.Process

   No documentation available.

7. mapMaybe :: forall (m :: Type -> Type) a b . Monad m => (a -> Maybe b) -> Stream m a -> Stream m b

   vector-stream	Data.Stream.Monadic

   No documentation available.

8. mapMaybe :: (Ord k, Semigroup v) => (a -> Maybe b) -> AnnotatedMap k v a -> AnnotatedMap k v b

   what4	What4.Utils.AnnotatedMap

   No documentation available.

9. mapMaybe :: (a -> Maybe b) -> List1 a -> [b]

   Agda	Agda.Utils.List1

   Like mapMaybe.

10. mapMaybe :: Ord k => (a -> Maybe b) -> Map k a -> Map k b

    hashmap	Data.HashMap

    Map values and collect the Just results.

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