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1. mapM :: (Monad m, Storable a, Storable b) => (a -> m b) -> Vector a -> m (Vector b)

   rio	RIO.Vector.Storable

   No documentation available.

2. mapM_ :: (Monad m, Storable a) => (a -> m b) -> Vector a -> m ()

   rio	RIO.Vector.Storable

   No documentation available.

3. mapMaybe :: (Storable a, Storable b) => (a -> Maybe b) -> Vector a -> Vector b

   rio	RIO.Vector.Storable

   No documentation available.

4. mapM :: (Monad m, Unbox a, Unbox b) => (a -> m b) -> Vector a -> m (Vector b)

   rio	RIO.Vector.Unboxed

   No documentation available.

5. mapM_ :: (Monad m, Unbox a) => (a -> m b) -> Vector a -> m ()

   rio	RIO.Vector.Unboxed

   No documentation available.

6. mapMaybe :: (Unbox a, Unbox b) => (a -> Maybe b) -> Vector a -> Vector b

   rio	RIO.Vector.Unboxed

   No documentation available.

7. mapWriter :: ((a, w) -> (b, w')) -> Writer w a -> Writer w' b

   rio	RIO.Writer

   Map both the return value and output of a computation using the given function.

   • runWriter (mapWriter f m) = f (runWriter
     m)

8. mapWriterT :: (m (a, w) -> n (b, w')) -> WriterT w m a -> WriterT w' n b

   rio	RIO.Writer

   Map both the return value and output of a computation using the given function.

   • runWriterT (mapWriterT f m) = f
     (runWriterT m)

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

   errors	Control.Error

   Map the unwrapped computation using the given function.

   • runExceptT (mapExceptT f m) = f
     (runExceptT m)

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

    errors	Control.Error

    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]
    

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