GHCJS.Foreign.Callback

Documentation

data Callback a

Instances

IsJSVal (Callback a)

Methods

jsval_ :: Callback a -> JSVal

data OnBlocked

The runtime tries to run synchronous threads to completion. Sometimes it's not possible to continue running a thread, for example when the thread tries to take an empty MVar. The runtime can then either throw a WouldBlockException, aborting the blocking action, or continue the thread asynchronously.

Constructors

ContinueAsync

continue the thread asynchronously if blocked

ThrowWouldBlock

throw WouldBlockException if blocked

Instances

Enum OnBlocked

Methods

succ :: OnBlocked -> OnBlocked

pred :: OnBlocked -> OnBlocked

toEnum :: Int -> OnBlocked

fromEnum :: OnBlocked -> Int

enumFrom :: OnBlocked -> [OnBlocked]

enumFromThen :: OnBlocked -> OnBlocked -> [OnBlocked]

enumFromTo :: OnBlocked -> OnBlocked -> [OnBlocked]

enumFromThenTo :: OnBlocked -> OnBlocked -> OnBlocked -> [OnBlocked]

Eq OnBlocked

Methods

(==) :: OnBlocked -> OnBlocked -> Bool

(/=) :: OnBlocked -> OnBlocked -> Bool

Data OnBlocked

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> OnBlocked -> c OnBlocked

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c OnBlocked

toConstr :: OnBlocked -> Constr

dataTypeOf :: OnBlocked -> DataType

dataCast1 :: Typeable (* -> *) t => (forall d. Data d => c (t d)) -> Maybe (c OnBlocked)

dataCast2 :: Typeable (* -> * -> *) t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c OnBlocked)

gmapT :: (forall b. Data b => b -> b) -> OnBlocked -> OnBlocked

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> OnBlocked -> r

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> OnBlocked -> r

gmapQ :: (forall d. Data d => d -> u) -> OnBlocked -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> OnBlocked -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> OnBlocked -> m OnBlocked

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> OnBlocked -> m OnBlocked

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> OnBlocked -> m OnBlocked

Ord OnBlocked

Methods

compare :: OnBlocked -> OnBlocked -> Ordering

(<) :: OnBlocked -> OnBlocked -> Bool

(<=) :: OnBlocked -> OnBlocked -> Bool

(>) :: OnBlocked -> OnBlocked -> Bool

(>=) :: OnBlocked -> OnBlocked -> Bool

max :: OnBlocked -> OnBlocked -> OnBlocked

min :: OnBlocked -> OnBlocked -> OnBlocked

Show OnBlocked

Methods

showsPrec :: Int -> OnBlocked -> ShowS

show :: OnBlocked -> String

showList :: [OnBlocked] -> ShowS

releaseCallback :: Callback a -> IO ()

When you create a callback, the Haskell runtime stores a reference to the exported IO action or function. This means that all data referenced by the exported value stays in memory, even if nothing outside the Haskell runtime holds a reference to to callback.

Use releaseCallback to free the reference. Subsequent calls from JavaScript to the callback will result in an exception.

asynchronous callbacks

asyncCallback

Arguments

:: IO ()

the action that the callback runs

-> IO (Callback (IO ()))

the callback

Make a callback (JavaScript function) that runs the supplied IO action in an asynchronous thread when called.

Call releaseCallback when done with the callback, freeing data referenced by the IO action.

asyncCallback1

Arguments

:: (JSVal -> IO ())

the function that the callback calls

-> IO (Callback (JSVal -> IO ()))

the calback

asyncCallback2

Arguments

:: (JSVal -> JSVal -> IO ())

the Haskell function that the callback calls

-> IO (Callback (JSVal -> JSVal -> IO ()))

the callback

asyncCallback3

Arguments

:: (JSVal -> JSVal -> JSVal -> IO ())

the Haskell function that the callback calls

-> IO (Callback (JSVal -> JSVal -> JSVal -> IO ()))

the callback

synchronous callbacks

syncCallback

Arguments

:: OnBlocked

what to do when the thread blocks

-> IO ()

the Haskell action

-> IO (Callback (IO ()))

the callback

Make a callback (JavaScript function) that runs the supplied IO action in a synchronous thread when called.

Call releaseCallback when done with the callback, freeing memory referenced by the IO action.

syncCallback1

Arguments

:: OnBlocked

what to do when the thread blocks

-> (JSVal -> IO ())

the Haskell function

-> IO (Callback (JSVal -> IO ()))

the callback

Make a callback (JavaScript function) that runs the supplied IO function in a synchronous thread when called. The callback takes one argument that it passes as a JSVal value to the Haskell function.

Call releaseCallback when done with the callback, freeing data referenced by the function.

syncCallback2

Arguments

:: OnBlocked

what to do when the thread blocks

-> (JSVal -> JSVal -> IO ())

the Haskell function

-> IO (Callback (JSVal -> JSVal -> IO ()))

the callback

Make a callback (JavaScript function) that runs the supplied IO function in a synchronous thread when called. The callback takes two arguments that it passes as JSVal values to the Haskell function.

Call releaseCallback when done with the callback, freeing data referenced by the function.

syncCallback3

Arguments

:: OnBlocked

what to do when the thread blocks

-> (JSVal -> JSVal -> JSVal -> IO ())

the Haskell function

-> IO (Callback (JSVal -> JSVal -> JSVal -> IO ()))

the callback

Make a callback (JavaScript function) that runs the supplied IO function in a synchronous thread when called. The callback takes three arguments that it passes as JSVal values to the Haskell function.

Call releaseCallback when done with the callback, freeing data referenced by the function.

synchronous callbacks that return a value

syncCallback' :: IO JSVal -> IO (Callback (IO JSVal))

Make a callback (JavaScript function) that runs the supplied IO action in a synchronous thread when called.

Call releaseCallback when done with the callback, freeing memory referenced by the IO action.

syncCallback1' :: (JSVal -> IO JSVal) -> IO (Callback (JSVal -> IO JSVal))

syncCallback2' :: (JSVal -> JSVal -> IO JSVal) -> IO (Callback (JSVal -> JSVal -> IO JSVal))

syncCallback3' :: (JSVal -> JSVal -> JSVal -> IO JSVal) -> IO (Callback (JSVal -> JSVal -> JSVal -> IO JSVal))