Safe Haskell | Safe-Inferred |
---|---|
Language | Haskell98 |
- run :: RunBufferMode -> RunBufferMode -> IO a -> IO ()
- data RunBufferMode
- = RunNoBuffering
- | RunLineBuffering (Maybe Int)
- | RunBlockBuffering (Maybe Int) (Maybe Int)
- data Maybe a :: * -> *
Documentation
run :: RunBufferMode -> RunBufferMode -> IO a -> IO () Source
data RunBufferMode Source
data Maybe a :: * -> *
The Maybe
type encapsulates an optional value. A value of type
either contains a value of type Maybe
aa
(represented as
),
or it is empty (represented as Just
aNothing
). Using Maybe
is a good way to
deal with errors or exceptional cases without resorting to drastic
measures such as error
.
The Maybe
type is also a monad. It is a simple kind of error
monad, where all errors are represented by Nothing
. A richer
error monad can be built using the Either
type.