| Safe Haskell | Safe |
|---|
Ganeti.Utils.Monad
Description
Utility functions for MonadPlus operations
Synopsis
- mretryN :: MonadPlus m => Int -> (Int -> m a) -> m a
- retryMaybeN :: Monad m => Int -> (Int -> MaybeT m a) -> m (Maybe a)
- retryErrorN :: MonadError e m => Int -> (Int -> m a) -> m a
- anyM :: Monad m => (a -> m Bool) -> [a] -> m Bool
- allM :: Monad m => (a -> m Bool) -> [a] -> m Bool
- orM :: Monad m => [m Bool] -> m Bool
- unfoldrM :: Monad m => (a -> m (Maybe (b, a))) -> a -> m [b]
- unfoldrM' :: (Monad m, MonadPlus f) => (a -> m (Maybe (b, a))) -> a -> m (f b)
Documentation
mretryN :: MonadPlus m => Int -> (Int -> m a) -> m a Source #
Retries the given action up to n times.
The action signals failure by mzero.
retryMaybeN :: Monad m => Int -> (Int -> MaybeT m a) -> m (Maybe a) Source #
Retries the given action up to n times.
The action signals failure by mzero.
retryErrorN :: MonadError e m => Int -> (Int -> m a) -> m a Source #
Retries the given action up to n times until it succeeds.
If all actions fail, the error of the last one is returned.
The action is always run at least once, even if n is less than 1.
From monad-loops (until we can / want to depend on it):
anyM :: Monad m => (a -> m Bool) -> [a] -> m Bool Source #
Short-circuit any with a monadic predicate.
allM :: Monad m => (a -> m Bool) -> [a] -> m Bool Source #
Short-circuit all with a monadic predicate.