elerea 2.3.0 → 2.4.0

raw patch · 3 files changed

+110/−3 lines, 3 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• CHANGES +3/−0
• FRP/Elerea/Simple.hs +105/−1
• elerea.cabal +2/−2

@@ -1,3 +1,6 @@+2.4.0 - 111111+* added effectful signals to assist library writers+ 2.3.0 - 110627 * reimplemented clocked variant in a correct and more efficient way 

@@ -28,6 +28,12 @@     , transfer2     , transfer3     , transfer4+    -- * Signals with side effects+    , effectful+    , effectful1+    , effectful2+    , effectful3+    , effectful4     -- * Random sources     , noise     , getRandom@@ -251,6 +257,10 @@    addSignal (const sample) (const (() <$ sample)) ref pool +-- | Auxiliary function.+memoise :: IORef (Phase a) -> a -> IO a+memoise ref x = writeIORef ref (Updated undefined x) >> return x+ -- | Memoising combinator.  It can be used to cache results of -- applicative combinators in case they are used in several places. -- It is observationally equivalent to 'return' in the 'SignalGen'@@ -269,7 +279,7 @@ memo (S s) = SG $ \pool -> do   ref <- newIORef (Ready undefined) -  let sample = s >>= \x -> writeIORef ref (Updated undefined x) >> return x+  let sample = s >>= memoise ref    addSignal (const sample) (const (() <$ sample)) ref pool @@ -474,6 +484,100 @@ transfer4 x0 f s1 s2 s3 s4 = mfix $ \sig -> do     sig' <- delay x0 sig     memo (liftM5 f s1 s2 s3 s4 sig')++-- | A signal that executes a given IO action once at every sampling.+-- The IO action is constructed by an initialiser.+--+-- In essence, this combinator provides cooperative multitasking+-- capabilities, and its primary purpose is to assist library writers+-- in wrapping effectful APIs as conceptually pure signals.  If there+-- are several effectful signals in the system, their order of+-- execution is undefined and should not be relied on.+--+-- Example:+--+-- > do+-- >     act <- start $ effectful $ do+-- >       ref <- newIORef 0+-- >       return $ do+-- >         x <- readIORef ref+-- >         putStrLn $ "Count: " ++ show x+-- >         writeIORef ref $! x+1+-- >         return ()+-- >     replicateM_ 5 act+--+-- Output:+--+-- > Count: 0+-- > Count: 1+-- > Count: 2+-- > Count: 3+-- > Count: 4+effectful :: IO (IO a)             -- ^ initialiser that yields the action to be executed repeatedly+          -> SignalGen (Signal a)+effectful gen = SG $ \pool -> do+  ref <- newIORef (Ready undefined)+  act <- gen++  let sample = act >>= memoise ref++  addSignal (const sample) (const (() <$ sample)) ref pool++-- | A signal that executes a parametric IO action once at every+-- sampling.  The IO action is constructed by an initialiser, and the+-- parameter is supplied by another signal at every sampling step.+effectful1 :: IO (t -> IO a)        -- ^ initialiser that yields the action to be executed repeatedly+           -> Signal t              -- ^ parameter signal+           -> SignalGen (Signal a)+effectful1 gen (S s) = SG $ \pool -> do+  ref <- newIORef (Ready undefined)+  act <- gen++  let sample = s >>= act >>= memoise ref++  addSignal (const sample) (const (() <$ sample)) ref pool++-- | Like 'effectful1', but with two parameter signals.+effectful2 :: IO (t1 -> t2 -> IO a)  -- ^ initialiser that yields the action to be executed repeatedly+           -> Signal t1              -- ^ parameter signal 1+           -> Signal t2              -- ^ parameter signal 2+           -> SignalGen (Signal a)+effectful2 gen (S s1) (S s2) = SG $ \pool -> do+  ref <- newIORef (Ready undefined)+  act <- gen++  let sample = join (liftM2 act s1 s2) >>= memoise ref++  addSignal (const sample) (const (() <$ sample)) ref pool++-- | Like 'effectful1', but with three parameter signals.+effectful3 :: IO (t1 -> t2 -> t3 -> IO a)  -- ^ initialiser that yields the action to be executed repeatedly+           -> Signal t1                    -- ^ parameter signal 1+           -> Signal t2                    -- ^ parameter signal 2+           -> Signal t3                    -- ^ parameter signal 3+           -> SignalGen (Signal a)+effectful3 gen (S s1) (S s2) (S s3) = SG $ \pool -> do+  ref <- newIORef (Ready undefined)+  act <- gen++  let sample = join (liftM3 act s1 s2 s3) >>= memoise ref++  addSignal (const sample) (const (() <$ sample)) ref pool++-- | Like 'effectful1', but with four parameter signals.+effectful4 :: IO (t1 -> t2 -> t3 -> t4 -> IO a)  -- ^ initialiser that yields the action to be executed repeatedly+           -> Signal t1                          -- ^ parameter signal 1+           -> Signal t2                          -- ^ parameter signal 2+           -> Signal t3                          -- ^ parameter signal 3+           -> Signal t4                          -- ^ parameter signal 4+           -> SignalGen (Signal a)+effectful4 gen (S s1) (S s2) (S s3) (S s4) = SG $ \pool -> do+  ref <- newIORef (Ready undefined)+  act <- gen++  let sample = join (liftM4 act s1 s2 s3 s4) >>= memoise ref++  addSignal (const sample) (const (() <$ sample)) ref pool  -- | A random signal. --

@@ -1,5 +1,5 @@ Name:                elerea-Version:             2.3.0+Version:             2.4.0 Cabal-Version:       >= 1.2 Synopsis:            A minimalistic FRP library Category:            reactivity, FRP@@ -38,7 +38,7 @@  (<http://sgate.emt.bme.hu/documents/patai/publications/PataiWFLP2010.pdf>).  Author:              Patai Gergely-Maintainer:          Patai Gergely (patai@iit.bme.hu)+Maintainer:          Patai Gergely (patai.gergely@gmail.com) Copyright:           (c) 2009-2011, Patai Gergely License:             BSD3 License-File:        LICENSE