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1. untilMaybe :: forall (m :: Type -> Type) a b . Monad m => MSF m a b -> MSF m b Bool -> MSF (MaybeT m) a b

   dunai	Control.Monad.Trans.MSF.Maybe

   Run the first msf until the second one produces True from the output of the first.

2. mapMaybeS :: forall (m :: Type -> Type) a b . Monad m => MSF m a b -> MSF m (Maybe a) (Maybe b)

   dunai	Data.MonadicStreamFunction.Util

   Apply an MSF to every input. Freezes temporarily if the input is Nothing, and continues as soon as a Just is received.

3. elimMaybe :: forall a (p :: Maybe a ~> Type) (s :: Maybe a) . Sing s -> Apply p ('Nothing :: Maybe a) -> (forall (f0 :: a) . () => Sing f0 -> Apply p ('Just f0)) -> Apply p s

   eliminators	Data.Eliminator

   No documentation available.

4. EMaybe :: ElmDatatype -> ElmPrimitive

   elm-export	Elm

   No documentation available.

5. eitherMaybe :: Either () a -> Maybe a

   errors-ext	Control.Error.Extensions

   Converts Either to Maybe. Specialization of either.

   maybeEither . eitherMaybe = id
   

6. productMaybeWith :: (a -> b -> Maybe c) -> [[a]] -> [[b]] -> [[c]]

   extrapolate	Test.Extrapolate

   Take the product of lists of tiers by a function returning a Maybe value discarding Nothing values.

7. productMaybeWith :: (a -> b -> Maybe c) -> [[a]] -> [[b]] -> [[c]]

   extrapolate	Test.Extrapolate.Core

   Take the product of lists of tiers by a function returning a Maybe value discarding Nothing values.

8. eitherToMaybe :: Either e a -> Maybe a

   from-sum	Control.FromSum

   Convert an Either to a Maybe. A Right value becomes Just.

   >>> eitherToMaybe $ Right 3
   Just 3
   

   A Left value becomes Nothing.

   >>> eitherToMaybe $ Left "bye"
   Nothing
   

9. fromMaybe :: a -> Maybe a -> a

   from-sum	Control.FromSum

   The fromMaybe function takes a default value and a Maybe value. If the Maybe is Nothing, it returns the default value; otherwise, it returns the value contained in the Maybe.

   Examples

   Basic usage:

   >>> fromMaybe "" (Just "Hello, World!")
   "Hello, World!"
   

   >>> fromMaybe "" Nothing
   ""
   

   Read an integer from a string using readMaybe. If we fail to parse an integer, we want to return 0 by default:

   >>> import GHC.Internal.Text.Read ( readMaybe )
   
   >>> fromMaybe 0 (readMaybe "5")
   5
   
   >>> fromMaybe 0 (readMaybe "")
   0
   

10. fromMaybeExceptT :: forall (m :: Type -> Type) x a . Monad m => x -> Maybe a -> ExceptT x m a

    from-sum	Control.FromSum

    Lift a Maybe to an ExceptT with a default value for the case when the Maybe is Nothing. If the Maybe is Just, then just return the value like normal:

    >>> let justVal = Just True :: Maybe Bool
    
    >>> fromMaybeExceptT 5 justVal :: ExceptT Int Identity Bool
    ExceptT (Identity (Right True))
    

    If the Maybe is Nothing, then use the default value as the error value:

    >>> let nothingVal = Nothing :: Maybe Bool
    
    >>> fromMaybeExceptT 5 nothingVal :: ExceptT Int Identity Bool
    ExceptT (Identity (Left 5))
    

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