phantom-state 0.2.1.2 → 0.2.1.3

raw patch · 3 files changed

+50/−17 lines, 3 filesdep ~transformers

Dependency ranges changed: transformers

Files

• Control/Applicative/PhantomState.hs +19/−0
• bench/Main.hs +29/−15
• phantom-state.cabal +2/−2

@@ -1,4 +1,6 @@ +{-# LANGUAGE CPP #-}+ -- | Phantom State Transformer type and functions. module Control.Applicative.PhantomState (     PhantomStateT@@ -12,6 +14,13 @@  import Control.Applicative import Data.Functor.Identity+-- Conditional imports+#if !MIN_VERSION_base(4,8,0)+import Data.Monoid (Monoid (..))+#endif+#if MIN_VERSION_base(4,9,0) && !MIN_VERSION_base(4,10,0)+import Data.Semigroup (Semigroup (..))+#endif  -- | The Phantom State Transformer is like the --   State Monad Transformer, but it does not hold@@ -103,3 +112,13 @@   empty = PhantomStateT (const empty)   {-# INLINE (<|>) #-}   PhantomStateT f <|> PhantomStateT g = PhantomStateT (\x -> f x <|> g x)++instance Monad m => Monoid (PhantomStateT s m a) where+  {-# INLINE mempty #-}+  mempty = pure undefined++#if MIN_VERSION_base(4,9,0)+instance Monad m => Semigroup (PhantomStateT s m a) where+  {-# INLINE (<>) #-}+  (<>) = (*>)+#endif

@@ -16,38 +16,52 @@ -- phantom-state import Control.Applicative.PhantomState +replicateA_ :: Applicative f => Int -> f a -> f ()+replicateA_ n f = sequenceA_ (replicate n f)+ createVector1 :: Int -> V.Vector Int createVector1 n = V.create $ do   v <- MV.unsafeNew n-  let step = do -        i <- get-        lift $ MV.write v i i-        put (i+1)-  execStateT (replicateM n step) 0+  let step = StateT $ \i -> do+        MV.unsafeWrite v i i+        pure ((),i+1)+  execStateT (replicateA_ n step) 0   return v -replicateA_ :: Applicative f => Int -> f a -> f ()-replicateA_ n f = sequenceA_ (replicate n f)- createVector2 :: Int -> V.Vector Int createVector2 n = V.create $ do   v <- MV.unsafeNew n-  let step = useAndChangeState $ \i -> MV.write v i i >> pure (i+1)+  let step = useAndChangeState $ \i -> do+        MV.unsafeWrite v i i+        pure (i+1)   runPhantomStateT (replicateA_ n step) 0   return v  createVector3 :: Int -> V.Vector Int createVector3 n = V.create $ do   v <- MV.unsafeNew n-  mapM_ (\i -> MV.write v i i) [0..n-1]+  mapM_ (\i -> MV.unsafeWrite v i i) [0..n-1]   return v +createVector4 :: Int -> V.Vector Int+createVector4 n = V.create $ do+  v <- MV.unsafeNew n+  let loop = do i <- get+                if i == n+                   then pure ()+                   else do lift $ MV.write v i i+                           modify (+1)+                           loop+  execStateT loop 0+  return v+ main :: IO () main = defaultMain-  [ bgroup "vector"-      [ bench "generate" $ nf (\i -> V.generate i id) 10000-      , bench "state" $ nf createVector1 10000-      , bench "phantom-state" $ nf createVector2 10000-      , bench "mapM_" $ nf createVector3 10000+  [ bgroup "vector-create"+      [ bench "generate" $ whnf (\i -> V.generate i id) 10000+      , bench "state" $ whnf createVector1 10000+      , bench "phantom-state" $ whnf createVector2 10000+      , bench "mapM_" $ whnf createVector3 10000+      , bench "state-loop" $ whnf createVector4 10000         ]   ]

@@ -1,5 +1,5 @@ name:                phantom-state-version:             0.2.1.2+version:             0.2.1.3 synopsis:            Phantom State Transformer. Like State Monad, but without values. description:         A monad transformer that mimics the State Monad Transformer from the                      <http://hackage.haskell.org/package/transformers transformers> package,@@ -22,7 +22,7 @@ library   exposed-modules: Control.Applicative.PhantomState   build-depends: base >= 4.7 && < 5-               , transformers >= 0.3 && < 0.6+               , transformers >= 0.3   default-language: Haskell2010   ghc-options: -O2 -Wall