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1. mapMaybeM :: Monad m => (a -> m (Maybe b)) -> [a] -> m [b]

   relude	Relude.Monad.Maybe

   The monadic version of the mapMaybe function.

   >>> :{
   evenInHalf :: Int -> IO (Maybe Int)
   evenInHalf n
   | even n = pure $ Just $ n `div` 2
   | otherwise = pure Nothing
   :}
   

   >>> mapMaybeM evenInHalf [1..10]
   [1,2,3,4,5]
   

2. mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c])

   relude	Relude.Monad.Reexport

   The mapAndUnzipM function maps its first argument over a list, returning the result as a pair of lists. This function is mainly used with complicated data structures or a state monad.

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

   relude	Relude.Monad.Reexport

   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]
   

4. mappend :: Monoid a => a -> a -> a

   relude	Relude.Monoid

   An associative operation NOTE: This method is redundant and has the default implementation mappend = (<>) since base-4.11.0.0. Should it be implemented manually, since mappend is a synonym for (<>), it is expected that the two functions are defined the same way. In a future GHC release mappend will be removed from Monoid.

5. mapExcept :: (Either e a -> Either e' b) -> Except e a -> Except e' b

   selective	Control.Selective.Trans.Except

   No documentation available.

6. mapExceptT :: (m (Either e a) -> n (Either e' b)) -> ExceptT e m a -> ExceptT e' n b

   selective	Control.Selective.Trans.Except

   No documentation available.

7. mapFields :: forall c (ts :: [(Symbol, Type)]) . RecMapMethod c ElField ts => (forall a . c a => a -> a) -> FieldRec ts -> FieldRec ts

   vinyl	Data.Vinyl

   Apply a typeclass method to each field of a FieldRec. This is a specialization of rmapMethod.

8. mapFields :: forall c (ts :: [(Symbol, Type)]) . RecMapMethod c ElField ts => (forall a . c a => a -> a) -> FieldRec ts -> FieldRec ts

   vinyl	Data.Vinyl.Class.Method

   Apply a typeclass method to each field of a FieldRec. This is a specialization of rmapMethod.

9. mapDefault :: Ord key => elem -> key -> Accessor (Map key elem) elem

   distributed-process	Control.Distributed.Process.Internal.StrictContainerAccessors

   No documentation available.

10. mapMaybe :: Ord key => key -> Accessor (Map key elem) (Maybe elem)

    distributed-process	Control.Distributed.Process.Internal.StrictContainerAccessors

    No documentation available.

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