Reflex.Host.Basic

BasicGuest provides instances that most Reflex programs need:

• MonadIO
• MonadFix
• MonadSample
• MonadHold
• NotReady
• PostBuild
• PerformEvent — Performable (BasicGuest t m) has MonadIO
• TriggerEvent
• Adjustable

For some usage examples, see the example directory.

Running the host

basicHostWithQuit :: (forall t m. BasicGuestConstraints t m => BasicGuest t m (Event t ())) -> IO ()

Run a BasicGuest, and return when the Event returned by the BasicGuest fires.

Each host runs on a separate spider timeline, so you can launch multiple hosts via forkIO or forkOS and they will not mutex each other.

NOTE: If you want to capture values from a build before the network starts firing (e.g., to hand off event triggers to another thread), populate an MVar (if threading) or IORef as you build the network. If you receive errors about untouchable type variables while doing this, add type annotations to constrain the MVar or IORef contents before passing them to the function that returns your BasicGuest. See the Multithread.hs example for a demonstration of this pattern, and where to put the type annotations.

basicHostForever :: (forall t m. BasicGuestConstraints t m => BasicGuest t m ()) -> IO ()

Run a BasicGuest without a quit Event.

basicHostForever guest = basicHostWithQuit $ never <$ guest

Types

data BasicGuest t (m :: * -> *) a

The basic guest type. Try not to code against it directly; instead ask for the features you need MTL-style:

myFunction :: (Reflex t, MonadHold m) => ...

Instances

ReflexHost t => NotReady t (BasicGuest t m)

Defined in Reflex.Host.Basic

Methods

notReadyUntil :: Event t a -> BasicGuest t m ()

notReady :: BasicGuest t m ()

(ReflexHost t, Ref m ~ Ref IO, MonadRef (HostFrame t), Ref (HostFrame t) ~ Ref IO, MonadIO (HostFrame t), PrimMonad (HostFrame t), MonadIO m) => PerformEvent t (BasicGuest t m)

Defined in Reflex.Host.Basic

Associated Types

type Performable (BasicGuest t m) :: Type -> Type

Methods

performEvent :: Event t (Performable (BasicGuest t m) a) -> BasicGuest t m (Event t a)

performEvent_ :: Event t (Performable (BasicGuest t m) ()) -> BasicGuest t m ()

(ReflexHost t, MonadRef (HostFrame t), Ref (HostFrame t) ~ Ref IO) => TriggerEvent t (BasicGuest t m)

Defined in Reflex.Host.Basic

Methods

newTriggerEvent :: BasicGuest t m (Event t a, a -> IO ())

newTriggerEventWithOnComplete :: BasicGuest t m (Event t a, a -> IO () -> IO ())

newEventWithLazyTriggerWithOnComplete :: ((a -> IO () -> IO ()) -> IO (IO ())) -> BasicGuest t m (Event t a)

ReflexHost t => PostBuild t (BasicGuest t m)

Defined in Reflex.Host.Basic

Methods

getPostBuild :: BasicGuest t m (Event t ())

(ReflexHost t, Ref m ~ Ref IO, MonadHold t m, PrimMonad (HostFrame t)) => Adjustable t (BasicGuest t m)

Defined in Reflex.Host.Basic

Methods

runWithReplace :: BasicGuest t m a -> Event t (BasicGuest t m b) -> BasicGuest t m (a, Event t b)

traverseIntMapWithKeyWithAdjust :: (Key -> v -> BasicGuest t m v') -> IntMap v -> Event t (PatchIntMap v) -> BasicGuest t m (IntMap v', Event t (PatchIntMap v'))

traverseDMapWithKeyWithAdjust :: GCompare k => (forall a. k a -> v a -> BasicGuest t m (v' a)) -> DMap k v -> Event t (PatchDMap k v) -> BasicGuest t m (DMap k v', Event t (PatchDMap k v'))

traverseDMapWithKeyWithAdjustWithMove :: GCompare k => (forall a. k a -> v a -> BasicGuest t m (v' a)) -> DMap k v -> Event t (PatchDMapWithMove k v) -> BasicGuest t m (DMap k v', Event t (PatchDMapWithMove k v'))

ReflexHost t => MonadSample (t :: Type) (BasicGuest t m)

Defined in Reflex.Host.Basic

Methods

sample :: Behavior t a -> BasicGuest t m a

(ReflexHost t, MonadHold t m) => MonadHold (t :: Type) (BasicGuest t m)

Defined in Reflex.Host.Basic

Methods

hold :: a -> Event t a -> BasicGuest t m (Behavior t a)

holdDyn :: a -> Event t a -> BasicGuest t m (Dynamic t a)

holdIncremental :: Patch p => PatchTarget p -> Event t p -> BasicGuest t m (Incremental t p)

buildDynamic :: PushM t a -> Event t a -> BasicGuest t m (Dynamic t a)

headE :: Event t a -> BasicGuest t m (Event t a)

ReflexHost t => Monad (BasicGuest t m)

Defined in Reflex.Host.Basic

Methods

(>>=) :: BasicGuest t m a -> (a -> BasicGuest t m b) -> BasicGuest t m b

(>>) :: BasicGuest t m a -> BasicGuest t m b -> BasicGuest t m b

return :: a -> BasicGuest t m a

fail :: String -> BasicGuest t m a

ReflexHost t => Functor (BasicGuest t m)

Defined in Reflex.Host.Basic

Methods

fmap :: (a -> b) -> BasicGuest t m a -> BasicGuest t m b

(<$) :: a -> BasicGuest t m b -> BasicGuest t m a

ReflexHost t => MonadFix (BasicGuest t m)

Defined in Reflex.Host.Basic

Methods

mfix :: (a -> BasicGuest t m a) -> BasicGuest t m a

ReflexHost t => Applicative (BasicGuest t m)

Defined in Reflex.Host.Basic

Methods

pure :: a -> BasicGuest t m a

(<*>) :: BasicGuest t m (a -> b) -> BasicGuest t m a -> BasicGuest t m b

liftA2 :: (a -> b -> c) -> BasicGuest t m a -> BasicGuest t m b -> BasicGuest t m c

(*>) :: BasicGuest t m a -> BasicGuest t m b -> BasicGuest t m b

(<*) :: BasicGuest t m a -> BasicGuest t m b -> BasicGuest t m a

(ReflexHost t, MonadIO (HostFrame t)) => MonadIO (BasicGuest t m)

Defined in Reflex.Host.Basic

Methods

liftIO :: IO a -> BasicGuest t m a

type Performable (BasicGuest t m)

Defined in Reflex.Host.Basic

type Performable (BasicGuest t m) = HostFrame t

type BasicGuestConstraints t (m :: * -> *) = (MonadReflexHost t m, MonadHold t m, MonadSample t m, Ref m ~ Ref IO, MonadRef (HostFrame t), Ref (HostFrame t) ~ Ref IO, MonadIO (HostFrame t), PrimMonad (HostFrame t), MonadIO m, MonadFix m)

Constraints provided by a BasicGuest, when run by basicHostWithQuit or basicHostForever.

Utilities

repeatUntilQuit

Arguments

:: BasicGuestConstraints t m

=> IO a

Action to repeatedly run

-> Event t ()

Event to stop the action

-> BasicGuest t m (Event t a)

Augment a BasicGuest with an action that is repeatedly run until the provided Event fires. Each time the action completes, the returned Event will fire.

Example - providing a 'tick' Event to a network

myNetwork
  :: (Reflex t, MonadHold t m, MonadFix m)
  => Event t ()
  -> m (Dynamic t Int)
myNetwork = count

myGuest :: BasicGuestConstraints t m => BasicGuest t m (Event t ())
myGuest = mdo
  eTick <- repeatUntilQuit (void $ threadDelay 1000000) eQuit
  let
    eCountUpdated = updated dCount
    eQuit = () <$ ffilter (==5) eCountUpdated
  dCount <- myNetwork eTick

  performEvent_ $ liftIO . print <$> eCountUpdated
  pure eQuit

main :: IO ()
main = basicHostWithQuit myGuest

repeatUntilQuit_

Arguments

:: BasicGuestConstraints t m

=> IO a

Action to repeatedly run

-> Event t ()

Event to stop the action

-> BasicGuest t m ()

Like repeatUntilQuit, but it doesn't do anything with the result of the action. May be a little more efficient if you don't need it.