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1. mapMaybe :: (a -> Maybe b) -> NonEmptyVector a -> Vector b

   nonempty-vector	Data.Vector.NonEmpty

   O(n) Drop elements when predicate returns Nothing If no elements satisfy the predicate, the resulting vector may be empty.

   >>> mapMaybe (\a -> if a == 2 then Nothing else Just a) (unsafeFromList [1..3])
   [1,3]
   

2. mapMaybe :: List l => (a -> Maybe b) -> l a -> l b

   List	Data.List.Class

   No documentation available.

3. mapMaybe :: (a -> Maybe b) -> Trie a -> Maybe (Trie b)

   bcp47	Data.BCP47.Trie

   No documentation available.

4. mapMaybe :: (a -> Maybe b) -> Trie a -> Maybe (Trie b)

   bcp47	Data.BCP47.Trie.Internal

   No documentation available.

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

   cabal-install-solver	Distribution.Solver.Compat.Prelude

   The mapMaybe function is a version of map which can throw out elements. In particular, the functional argument returns something of type Maybe b. If this is Nothing, no element is added on to the result list. If it is Just b, then b is included in the result list.

   Examples

   Using mapMaybe f x is a shortcut for catMaybes $ map f x in most cases:

   >>> import GHC.Internal.Text.Read ( readMaybe )
   
   >>> let readMaybeInt = readMaybe :: String -> Maybe Int
   
   >>> mapMaybe readMaybeInt ["1", "Foo", "3"]
   [1,3]
   
   >>> catMaybes $ map readMaybeInt ["1", "Foo", "3"]
   [1,3]
   

   If we map the Just constructor, the entire list should be returned:

   >>> mapMaybe Just [1,2,3]
   [1,2,3]
   

6. mapMaybe :: Filtrable f => (a -> Maybe b) -> f a -> f b

   filtrable	Data.Filtrable

   Map the container with the given function, dropping the elements for which it returns Nothing.

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

   incipit-base	Incipit.Base

   The mapMaybe function is a version of map which can throw out elements. In particular, the functional argument returns something of type Maybe b. If this is Nothing, no element is added on to the result list. If it is Just b, then b is included in the result list.

   Examples

   Using mapMaybe f x is a shortcut for catMaybes $ map f x in most cases:

   >>> import GHC.Internal.Text.Read ( readMaybe )
   
   >>> let readMaybeInt = readMaybe :: String -> Maybe Int
   
   >>> mapMaybe readMaybeInt ["1", "Foo", "3"]
   [1,3]
   
   >>> catMaybes $ map readMaybeInt ["1", "Foo", "3"]
   [1,3]
   

   If we map the Just constructor, the entire list should be returned:

   >>> mapMaybe Just [1,2,3]
   [1,2,3]
   

8. mapMaybe :: (Key -> Maybe Key) -> IntMultiSet -> IntMultiSet

   multiset	Data.IntMultiSet

   O(n). Map and collect the Just results.

9. mapMaybe :: Ord b => (a -> Maybe b) -> MultiSet a -> MultiSet b

   multiset	Data.MultiSet

   O(n). Map and collect the Just results.

10. mapMaybe :: (a -> Maybe b) -> Event a -> Event b

    reactive-midyim	Reactive.Banana.MIDI.Utility

    No documentation available.

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