Safe Haskell | Safe-Infered |
---|

Utility functions for MonadPlus operations

- 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 aSource

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 aSource

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.