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1. mapMaybeWithKey :: (Key s k -> a -> Maybe b) -> Map s k a -> SomeMapWith (SupersetProof 'Regular s) k b

   refined-containers	Data.Map.Refined

   Apply a function to all values in a map, together with their corresponding keys, and collect only the Just results, returning a potentially smaller map.

2. mapMaybe :: forall s k a b . (a -> Maybe b) -> Map s k a -> SomeMapWith (SupersetProof 'Regular s) k b

   refined-containers	Data.Map.Strict.Refined

   Apply a function to all values in a map and collect only the Just results, returning a potentially smaller map.

3. mapMaybeWithKey :: (Key s k -> a -> Maybe b) -> Map s k a -> SomeMapWith (SupersetProof 'Regular s) k b

   refined-containers	Data.Map.Strict.Refined

   Apply a function to all values in a map, together with their corresponding keys, and collect only the Just results, returning a potentially smaller map.

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

   verset	Verset

   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]
   

5. mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()

   xmonad-contrib	XMonad.Config.Prime

   Map each element of a structure to a monadic action, evaluate these actions from left to right, and ignore the results. For a version that doesn't ignore the results see mapM. mapM_ is just like traverse_, but specialised to monadic actions.

6. data MapMSym0 (a1 :: TyFun a ~> m b t a ~> m t b)

   singletons-base	Control.Monad.Singletons

   No documentation available.

7. data MapMSym1 (a6989586621680752084 :: a ~> m b) (b1 :: TyFun t a m t b)

   singletons-base	Control.Monad.Singletons

   No documentation available.

8. type family MapMSym2 (a6989586621680752084 :: a ~> m b) (a6989586621680752085 :: t a) :: m t b

   singletons-base	Control.Monad.Singletons

   No documentation available.

9. type family MapM_ (a1 :: a ~> m b) (a2 :: t a) :: m ()

   singletons-base	Control.Monad.Singletons

   No documentation available.

10. data MapM_Sym0 (a1 :: TyFun a ~> m b t a ~> m ())

    singletons-base	Control.Monad.Singletons

    No documentation available.

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