- maybeError :: Maybe a -> String -> a
- maybeBool :: Maybe a -> Bool -> Bool
- maybeAlternate :: Maybe a -> a -> a
- maybeAlternateM :: Monad m => Maybe a -> m a -> m a
- maybeApply :: Maybe a -> (a -> b) -> Maybe b
- maybeApplyM :: Monad m => Maybe a -> (a -> m b) -> m (Maybe b)
- (?>=>) :: Monad m => Maybe a -> (a -> m (Maybe b)) -> m (Maybe b)
- (>?>=>) :: Monad m => m (Maybe a) -> (a -> m (Maybe b)) -> m (Maybe b)
- (?>=) :: Monad m => Maybe a -> (a -> m ()) -> m ()
- (>?>=) :: Monad m => m (Maybe a) -> (a -> m ()) -> m ()
- maybeBranch :: Monad m => Maybe a -> (a -> m b) -> m b -> m b
- maybeHead :: [a] -> Maybe a

# Documentation

maybeError :: Maybe a -> String -> aSource

Indicate error or return a.
This function for replace `fromJust`

, expression `fromJust x` is bad
when `x`

is `Nothing`

, so `maybeError`

allowed you customize error
information.

maybeAlternate :: Maybe a -> a -> aSource

Maybe alternative.

maybeAlternateM :: Monad m => Maybe a -> m a -> m aSource

Maybe alternative monad.

maybeApply :: Maybe a -> (a -> b) -> Maybe bSource

Apply maybe.

maybeApplyM :: Monad m => Maybe a -> (a -> m b) -> m (Maybe b)Source

Apply maybe with monad.

maybeBranch :: Monad m => Maybe a -> (a -> m b) -> m b -> m bSource

Maybe branch.