Safe Haskell | Safe-Inferred |
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Extra functions for Control.Exception. These functions provide looping, list operations and booleans. If you need a wider selection of monad loops and list generalisations, see http://hackage.haskell.org/package/monad-loops
- whenJust :: Applicative m => Maybe a -> (a -> m ()) -> m ()
- unit :: m () -> m ()
- partitionM :: Monad m => (a -> m Bool) -> [a] -> m ([a], [a])
- concatMapM :: Monad m => (a -> m [b]) -> [a] -> m [b]
- mapMaybeM :: Monad m => (a -> m (Maybe b)) -> [a] -> m [b]
- loopM :: Monad m => (a -> m (Either a b)) -> a -> m b
- whileM :: Monad m => m Bool -> m ()
- whenM :: Monad m => m Bool -> m () -> m ()
- unlessM :: Monad m => m Bool -> m () -> m ()
- ifM :: Monad m => m Bool -> m a -> m a -> m a
- notM :: Functor m => m Bool -> m Bool
- (||^) :: Monad m => m Bool -> m Bool -> m Bool
- (&&^) :: Monad m => m Bool -> m Bool -> m Bool
- orM :: Monad m => [m Bool] -> m Bool
- andM :: Monad m => [m Bool] -> m Bool
- anyM :: Monad m => (a -> m Bool) -> [a] -> m Bool
- allM :: Monad m => (a -> m Bool) -> [a] -> m Bool
- findM :: Monad m => (a -> m Bool) -> [a] -> m (Maybe a)
- firstJustM :: Monad m => (a -> m (Maybe b)) -> [a] -> m (Maybe b)
Documentation
whenJust :: Applicative m => Maybe a -> (a -> m ()) -> m ()Source
Perform some operation on Just
, given the field inside the Just
.
whenJust Nothing print == return () whenJust (Just 1) print == print 1
The identity function which requires the inner argument to be '()'. Useful for functions with overloaded return times.
\(x :: Maybe ()) -> unit x == x
partitionM :: Monad m => (a -> m Bool) -> [a] -> m ([a], [a])Source
A version of partition
that works with a monadic predicate.
partitionM (Just . even) [1,2,3] == Just ([2], [1,3]) partitionM (const Nothing) [1,2,3] == Nothing
concatMapM :: Monad m => (a -> m [b]) -> [a] -> m [b]Source
A version of concatMap
that works with a monadic predicate.
mapMaybeM :: Monad m => (a -> m (Maybe b)) -> [a] -> m [b]Source
A version of mapMaybe
that works with a monadic predicate.
loopM :: Monad m => (a -> m (Either a b)) -> a -> m bSource
A looping operation, where the predicate returns Left
as a seed for the next loop
or Right
to abort the loop.
firstJustM :: Monad m => (a -> m (Maybe b)) -> [a] -> m (Maybe b)Source