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

   bcp47	Data.BCP47.Trie.Internal

   No documentation available.

2. mapMaybe2 :: (a -> Maybe b) -> Trie2 a -> Maybe (Trie2 b)

   bcp47	Data.BCP47.Trie.Internal

   No documentation available.

3. mapArray :: Ix i => (Bool -> Bool) -> IOBitArray i -> IO (IOBitArray i)

   bitwise	Data.Array.BitArray.IO

   Alias for map.

4. mapIndices :: (Ix i, Ix j) => (i, i) -> (i -> j) -> IOBitArray j -> IO (IOBitArray i)

   bitwise	Data.Array.BitArray.IO

   Create a new array by reading from another.

5. mapArray :: Ix i => (Bool -> Bool) -> STBitArray s i -> ST s (STBitArray s i)

   bitwise	Data.Array.BitArray.ST

   Alias for map.

6. mapIndices :: (Ix i, Ix j) => (i, i) -> (i -> j) -> STBitArray s j -> ST s (STBitArray s i)

   bitwise	Data.Array.BitArray.ST

   Create a new array by reading from another.

7. mapHandle :: forall (e :: Effects) (es :: Effects) . (Handle h, e :> es) => h e -> h es

   bluefin-internal	Bluefin.Internal

   Used to create compound effects, i.e. handles that contain other handles.

8. mapHandleReader :: forall (h :: Effects -> Type) (e :: Effects) (es :: Effects) . (Handle h, e :> es) => HandleReader h e -> HandleReader h es

   bluefin-internal	Bluefin.Internal

   No documentation available.

9. mapOut :: forall outa outb (f :: Type -> Type) a . (outa -> outb) -> CmdParser f outa a -> CmdParser f outb a

   butcher	UI.Butcher.Monadic

   map over the out type argument

10. 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]
    

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