2e2e19d · reflex · git.iko.soy

271 return outE

272

273data ThrottleState b

274− = Immediate

274+ = ThrottleState_Immediate

275− | Buffered (ThrottleBuffer b)

275+ | ThrottleState_Buffered (ThrottleBuffer b)

276 deriving (Eq, Ord, Show, Functor, Foldable, Traversable, Generic, Data, Typeable)

277

278data ThrottleBuffer b

279− = BEmpty -- Empty conflicts with lens, and hiding it would require turning

279+ = ThrottleBuffer_Empty -- Empty conflicts with lens, and hiding it would require turning

280 -- on PatternSynonyms

281− | Full b

281+ | ThrottleBuffer_Full b

282 deriving (Eq, Ord, Show, Functor, Foldable, Traversable, Generic, Data, Typeable)

283

284instance Semigroup b => Semigroup (ThrottleBuffer b) where

285 x <> y = case x of

286− BEmpty -> y

286+ ThrottleBuffer_Empty -> y

287− Full b1 -> case y of

287+ ThrottleBuffer_Full b1 -> case y of

288− BEmpty -> x

288+ ThrottleBuffer_Empty -> x

289− Full b2 -> Full $ b1 <> b2

289+ ThrottleBuffer_Full b2 -> ThrottleBuffer_Full $ b1 <> b2

290 {-# INLINE (<>) #-}

291

292instance Semigroup b => Monoid (ThrottleBuffer b) where

293− mempty = BEmpty

293+ mempty = ThrottleBuffer_Empty

294 {-# INLINE mempty #-}

295 mappend = (<>)

296 {-# INLINE mappend #-}

300-- If the output event has not occurred recently, occurrences of the input event will cause the output event to fire immediately.

301-- The first parameter is a function that receives access to the output event, and should construct an event that fires when the receiver is

302-- ready for more input. For example, using @delay 20@ would give a simple time-based throttle.

303−throttleBatchWithLag :: (MonadFix m, MonadHold t m, PerformEvent t m, TriggerEvent t m, MonadIO (Performable m), Semigroup a) => (Event t () -> m (Event t ())) -> Event t a -> m (Event t a)

303+throttleBatchWithLag :: (MonadFix m, MonadHold t m, PerformEvent t m, Semigroup a) => (Event t () -> m (Event t ())) -> Event t a -> m (Event t a)

304-- Invariants:

305-- * Immediate mode must turn off whenever output is produced.

306-- * Output must be produced whenever immediate mode turns from on to off.

313 let f state x = case x of -- (Just $ newState, out)

314 This a -> -- If only the input event fires

315 case state of

316− Immediate -> -- and we're in immediate mode

316+ ThrottleState_Immediate -> -- and we're in immediate mode

317 -- Immediate mode turns off, and the buffer is empty.

318 -- We fire the output event with the input event value immediately.

319− (Just $ Buffered $ BEmpty, Just a)

319+ (Just $ ThrottleState_Buffered $ ThrottleBuffer_Empty, Just a)

320− Buffered b -> -- and we're not in immediate mode

320+ ThrottleState_Buffered b -> -- and we're not in immediate mode

321 -- Immediate mode remains off, and we accumulate the input value.

322 -- We don't fire the output event.

323− (Just $ Buffered $ b <> Full a, Nothing)

323+ (Just $ ThrottleState_Buffered $ b <> ThrottleBuffer_Full a, Nothing)

324 That _ -> -- If only the delayed output event fires,

325 case state of

326− Immediate -> -- and we're in immediate mode

326+ ThrottleState_Immediate -> -- and we're in immediate mode

327 -- Nothing happens.

328 (Nothing, Nothing)

329− Buffered BEmpty -> -- and the buffer is empty:

329+ ThrottleState_Buffered ThrottleBuffer_Empty -> -- and the buffer is empty:

330 -- Immediate mode turns back on, and the buffer remains empty.

331 -- We don't fire.

332− (Just Immediate, Nothing)

332+ (Just ThrottleState_Immediate, Nothing)

333− Buffered (Full b) -> -- and the buffer is full:

333+ ThrottleState_Buffered (ThrottleBuffer_Full b) -> -- and the buffer is full:

334 -- Immediate mode remains off, and the buffer is cleared.

335 -- We fire with the buffered value.

336− (Just $ Buffered BEmpty, Just b)

336+ (Just $ ThrottleState_Buffered ThrottleBuffer_Empty, Just b)

337 These a _ -> -- If both the input and delayed output event fire simultaneously:

338 case state of

339− Immediate -> -- and we're in immediate mode

339+ ThrottleState_Immediate -> -- and we're in immediate mode

340 -- Immediate mode turns off, and the buffer is empty.

341 -- We fire with the input event's value, as it is the most recent we have seen at this moment.

342− (Just $ Buffered BEmpty, Just a)

342+ (Just $ ThrottleState_Buffered ThrottleBuffer_Empty, Just a)

343− Buffered BEmpty -> -- and the buffer is empty:

343+ ThrottleState_Buffered ThrottleBuffer_Empty -> -- and the buffer is empty:

344 -- Immediate mode stays off, and the buffer remains empty.

345 -- We fire with the input event's value.

346− (Just $ Buffered BEmpty, Just a)

346+ (Just $ ThrottleState_Buffered ThrottleBuffer_Empty, Just a)

347− Buffered (Full b) -> -- and the buffer is full:

347+ ThrottleState_Buffered (ThrottleBuffer_Full b) -> -- and the buffer is full:

348 -- Immediate mode remains off, and the buffer is cleared.

349 -- We fire with everything including the buffered value.

350− (Just $ Buffered BEmpty, Just (b <> a))

350+ (Just $ ThrottleState_Buffered ThrottleBuffer_Empty, Just (b <> a))

351 rec (_stateDyn, outE) <- mapAccumMaybeDyn f

352− Immediate -- We start in immediate mode with an empty buffer.

352+ ThrottleState_Immediate -- We start in immediate mode with an empty buffer.

353 (align e delayed)

354 delayed <- lag (void outE)

355 return outE