(a -> m b) -> (b -> m c) -> a -> m c +base

(>=>) :: Monad m => (a -> m b) -> (b -> m c) -> (a -> m c)
base Control.Monad
Left-to-right Kleisli composition of monads.
(<=<) :: Monad m => (b -> m c) -> (a -> m b) -> (a -> m c)
base Control.Monad
Right-to-left Kleisli composition of monads. (>=>), with the arguments flipped
bracket :: IO a -> (a -> IO b) -> (a -> IO c) -> IO c
base Control.Exception.Base, base Control.Exception
When you want to acquire a resource, do some work with it, and then release the resource, it is a good idea to use bracket, because bracket will install the necessary exception handler to release the resource in the event that an exception is raised during the computation. If an exception is raised, then bracket will re-raise the exception (after performing the release). A common example is opening a file: > bracket > (openFile "filename" ReadMode) > (hClose) > (\fileHandle -> do { ... }) The arguments to bracket are in this order so that we can partially apply it, e.g.: > withFile name mode = bracket (openFile name mode) hClose
bracket :: IO a -> (a -> IO b) -> (a -> IO c) -> IO c
base Control.OldException
When you want to acquire a resource, do some work with it, and then release the resource, it is a good idea to use bracket, because bracket will install the necessary exception handler to release the resource in the event that an exception is raised during the computation. If an exception is raised, then bracket will re-raise the exception (after performing the release). A common example is opening a file: > bracket > (openFile "filename" ReadMode) > (hClose) > (\handle -> do { ... }) The arguments to bracket are in this order so that we can partially apply it, e.g.: > withFile name mode = bracket (openFile name mode) hClose
bracketOnError :: IO a -> (a -> IO b) -> (a -> IO c) -> IO c
base Control.Exception.Base, base Control.Exception
Like bracket, but only performs the final action if there was an exception raised by the in-between computation.
bracketOnError :: IO a -> (a -> IO b) -> (a -> IO c) -> IO c
base Control.OldException
Like bracket, but only performs the final action if there was an exception raised by the in-between computation.