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  1. catMaybes :: [Maybe a] -> [a]

    stratosphere Stratosphere.ResourceImports

    The catMaybes function takes a list of Maybes and returns a list of all the Just values.

    Examples

    Basic usage: 
    >>> catMaybes [Just 1, Nothing, Just 3]
[1,3]
    When constructing a list of Maybe values, catMaybes can be used to return all of the "success" results (if the list is the result of a map, then mapMaybe would be more appropriate): 
    >>> import GHC.Internal.Text.Read ( readMaybe )

>>> [readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ]
[Just 1,Nothing,Just 3]

>>> catMaybes $ [readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ]
[1,3]

  2. catMaybes :: forall t (m :: Type -> Type) a . (IsStream t, Monad m, Functor (t m)) => t m (Maybe a) -> t m a

    streamly Streamly.Internal.Data.Stream.IsStream

    In a stream of Maybes, discard Nothings and unwrap Justs. Pre-release

  3. mapMaybe :: forall t (m :: Type -> Type) a b . (IsStream t, Monad m) => (a -> Maybe b) -> t m a -> t m b

    streamly Streamly.Internal.Data.Stream.IsStream

    Map a Maybe returning function to a stream, filter out the Nothing elements, and return a stream of values extracted from Just. Equivalent to: 

    mapMaybe f = Stream.map fromJust . Stream.filter isJust . Stream.map f

  4. mapMaybeM :: (IsStream t, MonadAsync m, Functor (t m)) => (a -> m (Maybe b)) -> t m a -> t m b

    streamly Streamly.Internal.Data.Stream.IsStream

    Like mapMaybe but maps a monadic function. Equivalent to: 

    mapMaybeM f = Stream.map fromJust . Stream.filter isJust . Stream.mapM f
    Concurrent (do not use with fromParallel on infinite streams)

  5. writeMaybesWith :: forall (m :: Type -> Type) . MonadIO m => Int -> Socket -> Fold m (Maybe Word8) ()

    streamly Streamly.Internal.Network.Socket

    Write a stream of Maybe values. Keep buffering the Just values in an array. Write the array to the Handle as soon as a Nothing is encountered or the buffer size exceeds the specified limit. Pre-release

  6. mapMaybe :: forall t (m :: Type -> Type) a b . (IsStream t, Monad m) => (a -> Maybe b) -> t m a -> t m b

    streamly Streamly.Prelude

    Map a Maybe returning function to a stream, filter out the Nothing elements, and return a stream of values extracted from Just. Equivalent to: 

    mapMaybe f = Stream.map fromJust . Stream.filter isJust . Stream.map f

  7. mapMaybeM :: (IsStream t, MonadAsync m, Functor (t m)) => (a -> m (Maybe b)) -> t m a -> t m b

    streamly Streamly.Prelude

    Like mapMaybe but maps a monadic function. Equivalent to: 

    mapMaybeM f = Stream.map fromJust . Stream.filter isJust . Stream.mapM f
    Concurrent (do not use with fromParallel on infinite streams)

  8. putMaybeLineComment :: Maybe EpaComment -> P ()

    stylish-haskell Language.Haskell.Stylish.Printer

    No documentation available.

  9. partCompareListMaybe :: Eq a => [Maybe a] -> [Maybe a] -> Maybe Ordering

    swish Data.Ord.Partial

    Part-ordering comparison on lists of Maybe values.

  10. type BinMaybeFnApply a = a -> Bool -> BinMaybeFnDescr a -> [Maybe a] -> Maybe [a]

    swish Swish.Datatype

    altArgs support for binary function with provision for indicating inconsistent supplied values: function applicator type

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