From dfecce27eb845d78d2c4f2891ecb6e5baf125c0e Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra.kumar@gmail.com>
Date: Thu, 24 May 2018 17:35:18 +0530
Subject: [PATCH] Fix build for ghc-7.10 and 8.0

---
 stack-8.0.yaml |  1 +
 streamly.cabal |  1 +
 test/Prop.hs   | 18 +++++++++---------
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/stack-8.0.yaml b/stack-8.0.yaml
index 04c3d2d51..aed11c19b 100644
--- a/stack-8.0.yaml
+++ b/stack-8.0.yaml
@@ -2,6 +2,7 @@ resolver: lts-9.20
 packages:
 - '.'
 extra-deps:
+    - QuickCheck-2.10
     - lockfree-queue-0.2.3.1
     - simple-conduit-0.6.0
     - SDL-0.6.5.1
diff --git a/streamly.cabal b/streamly.cabal
index e07bd69b7..b5f90f8e7 100644
--- a/streamly.cabal
+++ b/streamly.cabal
@@ -64,6 +64,7 @@ extra-source-files:
     README.md
     bench.sh
     stack-7.10.yaml
+    stack-8.0.yaml
     stack.yaml
 
 source-repository head
diff --git a/test/Prop.hs b/test/Prop.hs
index cc78f0fd7..285972527 100644
--- a/test/Prop.hs
+++ b/test/Prop.hs
@@ -7,7 +7,6 @@ import Control.Monad (when)
 import Control.Applicative (ZipList(..))
 import Control.Concurrent (MVar, takeMVar, putMVar, newEmptyMVar)
 import Control.Monad (replicateM, replicateM_)
-import Control.Monad.IO.Class (liftIO)
 import Data.List (sort, foldl', scanl')
 import GHC.Word (Word8)
 
@@ -121,7 +120,7 @@ sourceUnfoldrM mv n = A.unfoldrM step 0
         if cnt > fromIntegral n
         then return Nothing
         else do
-            liftIO $ dbgMVar ("put sourceUnfoldrM " ++ msg) (putMVar mv ())
+            dbgMVar ("put sourceUnfoldrM " ++ msg) (putMVar mv ())
             return (Just (fromIntegral cnt, cnt + 1))
 
 concurrentUnfoldrM
@@ -142,15 +141,16 @@ concurrentUnfoldrM eq op n =
             A.toList $ do
                 x <- op (sourceUnfoldrM mv n)
                 let msg = show x ++ "/" ++ show n
-                if even x
-                then do
-                    liftIO $ dbgMVar ("first take concurrentUnfoldrM " ++ msg)
-                                (takeMVar mv)
-                    if n > x
-                    then liftIO $ dbgMVar ("second take concurrentUnfoldrM " ++ msg)
+                A.once $ do
+                    if even x
+                    then do
+                        dbgMVar ("first take concurrentUnfoldrM " ++ msg)
                                 (takeMVar mv)
+                        if n > x
+                        then dbgMVar ("second take concurrentUnfoldrM " ++ msg)
+                                     (takeMVar mv)
+                        else return ()
                     else return ()
-                else return ()
                 return x
         equals eq stream list