diff options
Diffstat (limited to 'libraries/base/Control')
| -rw-r--r-- | libraries/base/Control/Applicative.hs | 2 | ||||
| -rw-r--r-- | libraries/base/Control/Arrow.hs | 12 | ||||
| -rw-r--r-- | libraries/base/Control/Concurrent.hs | 9 | ||||
| -rw-r--r-- | libraries/base/Control/Monad/ST/Lazy/Imp.hs | 4 |
4 files changed, 14 insertions, 13 deletions
diff --git a/libraries/base/Control/Applicative.hs b/libraries/base/Control/Applicative.hs index a2f342f83f..6770234926 100644 --- a/libraries/base/Control/Applicative.hs +++ b/libraries/base/Control/Applicative.hs @@ -96,7 +96,7 @@ instance Monad m => Functor (WrappedMonad m) where fmap f (WrapMonad v) = WrapMonad (liftM f v) instance Monad m => Applicative (WrappedMonad m) where - pure = WrapMonad . return + pure = WrapMonad . pure WrapMonad f <*> WrapMonad v = WrapMonad (f `ap` v) instance MonadPlus m => Alternative (WrappedMonad m) where diff --git a/libraries/base/Control/Arrow.hs b/libraries/base/Control/Arrow.hs index 9d09544eeb..1cc6062516 100644 --- a/libraries/base/Control/Arrow.hs +++ b/libraries/base/Control/Arrow.hs @@ -93,16 +93,14 @@ class Category a => Arrow a where -- | Send the first component of the input through the argument -- arrow, and copy the rest unchanged to the output. first :: a b c -> a (b,d) (c,d) + first = (*** id) -- | A mirror image of 'first'. -- -- The default definition may be overridden with a more efficient -- version if desired. second :: a b c -> a (d,b) (d,c) - second f = arr swap >>> first f >>> arr swap - where - swap :: (x,y) -> (y,x) - swap ~(x,y) = (y,x) + second = (id ***) -- | Split the input between the two argument arrows and combine -- their output. Note that this is in general not a functor. @@ -110,7 +108,8 @@ class Category a => Arrow a where -- The default definition may be overridden with a more efficient -- version if desired. (***) :: a b c -> a b' c' -> a (b,b') (c,c') - f *** g = first f >>> second g + f *** g = first f >>> arr swap >>> first g >>> arr swap + where swap ~(x,y) = (y,x) -- | Fanout: send the input to both argument arrows and combine -- their output. @@ -141,8 +140,6 @@ class Category a => Arrow a where instance Arrow (->) where arr f = f - first f = f *** id - second f = id *** f -- (f *** g) ~(x,y) = (f x, g y) -- sorry, although the above defn is fully H'98, nhc98 can't parse it. (***) f g ~(x,y) = (f x, g y) @@ -314,7 +311,6 @@ instance Arrow a => Applicative (ArrowMonad a) where ArrowMonad f <*> ArrowMonad x = ArrowMonad (f &&& x >>> arr (uncurry id)) instance ArrowApply a => Monad (ArrowMonad a) where - return x = ArrowMonad (arr (\_ -> x)) ArrowMonad m >>= f = ArrowMonad $ m >>> arr (\x -> let ArrowMonad h = f x in (h, ())) >>> app diff --git a/libraries/base/Control/Concurrent.hs b/libraries/base/Control/Concurrent.hs index 35248bfba3..1786c3ded3 100644 --- a/libraries/base/Control/Concurrent.hs +++ b/libraries/base/Control/Concurrent.hs @@ -3,6 +3,7 @@ , MagicHash , UnboxedTuples , ScopedTypeVariables + , RankNTypes #-} {-# OPTIONS_GHC -fno-warn-deprecations #-} -- kludge for the Control.Concurrent.QSem, Control.Concurrent.QSemN @@ -73,6 +74,7 @@ module Control.Concurrent ( -- $boundthreads rtsSupportsBoundThreads, forkOS, + forkOSWithUnmask, isCurrentThreadBound, runInBoundThread, runInUnboundThread, @@ -180,7 +182,7 @@ attribute will block all other threads. -} --- | fork a thread and call the supplied function when the thread is about +-- | Fork a thread and call the supplied function when the thread is about -- to terminate, with an exception or a returned value. The function is -- called with asynchronous exceptions masked. -- @@ -316,6 +318,11 @@ forkOS action0 return tid | otherwise = failNonThreaded +-- | Like 'forkIOWithUnmask', but the child thread is a bound thread, +-- as with 'forkOS'. +forkOSWithUnmask :: ((forall a . IO a -> IO a) -> IO ()) -> IO ThreadId +forkOSWithUnmask io = forkOS (io unsafeUnmask) + -- | Returns 'True' if the calling thread is /bound/, that is, if it is -- safe to use foreign libraries that rely on thread-local state from the -- calling thread. diff --git a/libraries/base/Control/Monad/ST/Lazy/Imp.hs b/libraries/base/Control/Monad/ST/Lazy/Imp.hs index 55b28cfc9a..c99912e62d 100644 --- a/libraries/base/Control/Monad/ST/Lazy/Imp.hs +++ b/libraries/base/Control/Monad/ST/Lazy/Imp.hs @@ -71,13 +71,11 @@ instance Functor (ST s) where (f r,new_s) instance Applicative (ST s) where - pure = return + pure a = ST $ \ s -> (a,s) (<*>) = ap instance Monad (ST s) where - return a = ST $ \ s -> (a,s) - m >> k = m >>= \ _ -> k fail s = error s (ST m) >>= k |