b1d8d7a · effectful · git.iko.soy

git.iko.soy/effectful

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Add ST reference to the countdown benchmark

b1d8d7aAndrzej Rybczak5 years ago

bench/Countdown.hs+22

compare with master

unifiedsplit

@@ -1,7 +1,9 @@

1{-# LANGUAGE CPP #-}

2module Countdown where

4+import Control.Monad.ST

4import Data.Functor.Identity

5import Data.Functor.Identity

6+import Data.STRef

6-- eff

8-- eff

7#ifdef VERSION_eff

9#ifdef VERSION_eff

@@ -47,6 +49,26 @@ countdownRef :: Integer -> (Integer, Integer)

47countdownRef n = if n <= 0 then (n, n) else countdownRef $ n - 1

49countdownRef n = if n <= 0 then (n, n) else countdownRef $ n - 1

48{-# NOINLINE countdownRef #-}

50{-# NOINLINE countdownRef #-}

52+----------------------------------------

53+-- ST

54+

55+programST :: STRef s Integer -> ST s Integer

56+programST ref = do

57+ n <- readSTRef ref

58+ if n <= 0

59+ then pure n

60+ else do

61+ writeSTRef ref $! n - 1

62+ programST ref

63+{-# NOINLINE programST #-}

64+

65+countdownST :: Integer -> (Integer, Integer)

66+countdownST n = runST $ do

67+ ref <- newSTRef n

68+ a <- programST ref

69+ s <- readSTRef ref

70+ pure (a, s)

71+

50----------------------------------------

72----------------------------------------

51-- mtl

73-- mtl

bench/Main.hs+2−1

@@ -22,7 +22,8 @@ main = defaultMain

22countdown :: Integer -> Benchmark

23countdown n = bgroup (show n)

24 [ bgroup "shallow"

25− [ bench "reference" $ nf countdownRef n

25+ [ bench "reference (pure)" $ nf countdownRef n

26+ , bench "reference (ST)" $ nf countdownST n

26 , bench "effectful (pure-static)" $ nf countdownEffectfulStatic n

27 , bench "effectful (pure-static)" $ nf countdownEffectfulStatic n

27 , bench "effectful (pure-dynamic)" $ nf countdownEffectfulDynPure n

28 , bench "effectful (pure-dynamic)" $ nf countdownEffectfulDynPure n

28 , bench "effectful (MVar-static)" $ nf countdownEffectfulMVar n

29 , bench "effectful (MVar-static)" $ nf countdownEffectfulMVar n