dunai 0.5 → 0.5.1

raw patch · 2 files changed

+20/−7 lines, 2 files

Files

• dunai.cabal +1/−1
• src/Control/Monad/Trans/MSF/Except.hs +19/−6

@@ -1,5 +1,5 @@ name:                dunai-version:             0.5+version:             0.5.1 synopsis:            Generalised reactive framework supporting classic, arrowized and monadic FRP. homepage:            https://github.com/ivanperez-keera/dunai description:

@@ -1,4 +1,5 @@ {-# LANGUAGE Arrows              #-}+{-# LANGUAGE CPP                 #-} {-# LANGUAGE Rank2Types          #-} -- | 'MSF's in the 'ExceptT' monad are monadic stream functions --   that can throw exceptions,@@ -23,6 +24,18 @@ import Data.MonadicStreamFunction import Data.MonadicStreamFunction.InternalCore +-- External, necessary for older base versions+#if __GLASGOW_HASKELL__ < 802+fromLeft  :: a -> Either a b -> a+fromLeft  _ (Left  a) = a+fromLeft  a (Right _) = a+fromRight :: b -> Either a b -> b+fromRight _ (Right b) = b+fromRight b (Left  _) = b+#else+import           Data.Either                (fromLeft, fromRight)+#endif+ -- * Throwing exceptions  -- | Throw the exception 'e' whenever the function evaluates to 'True'.@@ -182,11 +195,11 @@ safely :: Monad m => MSFExcept m a b Empty -> MSF m a b safely (MSFExcept msf) = morphS fromExcept msf   where+    -- We can assume that the pattern @Left e@ will not occur,+    -- since @e@ would have to be of type @Empty@.     fromExcept ma = do-      -- We can assume that the pattern @Left e@ will not occur,-      -- since @e@ would have to be of type @Empty@.-      Right a <- runExceptT ma-      return a+      rightMa <- runExceptT ma+      return $ fromRight (error "safely: Received `Left`") rightMa  -- | An 'MSF' without an 'ExceptT' layer never throws an exception, --   and can thus have an arbitrary exception type.@@ -232,8 +245,8 @@ -- | Reactimates an 'MSFExcept' until it throws an exception. reactimateExcept :: Monad m => MSFExcept m () () e -> m e reactimateExcept msfe = do-  Left e <- runExceptT $ reactimate $ runMSFExcept msfe-  return e+  leftMe <- runExceptT $ reactimate $ runMSFExcept msfe+  return $ fromLeft (error "reactimateExcept: Received `Right`") leftMe  -- | Reactimates an 'MSF' until it returns 'True'. reactimateB :: Monad m => MSF m () Bool -> m ()