| Safe Haskell | Safe-Inferred |
|---|
Exception
- module Control.Exception
- catchIO :: IO a -> (IOException -> IO a) -> IO a
- handleIO :: (IOException -> IO a) -> IO a -> IO a
- tryIO :: IO a -> IO (Either IOException a)
- class Monad m => ExceptionMonad m where
- gtry :: (ExceptionMonad m, Exception e) => m a -> m (Either e a)
- ghandle :: (ExceptionMonad m, Exception e) => (e -> m a) -> m a -> m a
- gonException :: ExceptionMonad m => m a -> m b -> m a
Documentation
module Control.Exception
class Monad m => ExceptionMonad m whereSource
A monad that can catch exceptions. A minimal definition
requires a definition of gcatch.
Implementations on top of IO should implement gblock and gunblock to
eventually call the primitives block and
unblock respectively. These are used for
implementations that support asynchronous exceptions. The default
implementations of gbracket and gfinally use gblock and gunblock
thus rarely require overriding.
Methods
gcatch :: Exception e => m a -> (e -> m a) -> m aSource
gmask :: ((m a -> m a) -> m b) -> m bSource
gbracket :: m a -> (a -> m b) -> (a -> m c) -> m cSource
Instances
gtry :: (ExceptionMonad m, Exception e) => m a -> m (Either e a)Source
ghandle :: (ExceptionMonad m, Exception e) => (e -> m a) -> m a -> m aSource
gonException :: ExceptionMonad m => m a -> m b -> m aSource
Always executes the first argument. If this throws an exception the second argument is executed and the exception is raised again.