550eed4 · streamly · git.iko.soy

git.iko.soy/streamly

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Make monoid instance append two computations in order

550eed4Harendra Kumar9 years ago

src/Asyncly/AsyncT.hs+4−3

compare with master

unifiedsplit

@@ -281,9 +281,10 @@ instance MonadAsync m => MonadPlus (AsyncT m) where

281 mzero = empty

282 mplus = (<|>)

283

284+-- | Appends the results of two AsyncT computations in order.

284−instance (Monoid a, Monad m) => Monoid (AsyncT m a) where

285+instance MonadAsync m => Monoid (AsyncT m a) where

285− mappend x y = mappend <$> x <*> y

286− mempty = return mempty

286+ mempty = empty

287+ mappend x y = serially x y

287

288

288------------------------------------------------------------------------------

289------------------------------------------------------------------------------

289-- Num

290-- Num

test/Main.hs+3

@@ -3,6 +3,7 @@ module Main (main) where

3import Asyncly

4import Control.Applicative ((<|>))

5import Control.Concurrent (myThreadId, threadDelay)

6+import Data.Monoid ((<>))

6import Control.Monad.IO.Class (liftIO)

7import Control.Monad.IO.Class (liftIO)

7import Data.List (nub, sort)

8import Data.List (nub, sort)

8import Test.Hspec

9import Test.Hspec

@@ -23,6 +24,8 @@ main = hspec $ do

23 toList (return 1 >> return 2) `shouldReturn` ([2] :: [Int])

24 toList (return 1 >> return 2) `shouldReturn` ([2] :: [Int])

24 it "Bind and toList" $

25 it "Bind and toList" $

25 toList (do x <- return 1; y <- return 2; return (x + y)) `shouldReturn` ([3] :: [Int])

26 toList (do x <- return 1; y <- return 2; return (x + y)) `shouldReturn` ([3] :: [Int])

27+ it "Monoid composition" $

28+ toList (return 0 <> return 1) `shouldReturn` ([0, 1] :: [Int])

26 it "Alternative composition" $

29 it "Alternative composition" $

27 ((toList $ (return 0 <|> return 1)) >>= return . sort) `shouldReturn` ([0, 1] :: [Int])

30 ((toList $ (return 0 <|> return 1)) >>= return . sort) `shouldReturn` ([0, 1] :: [Int])

28 {-

31 {-