Lazy pattern matching for compiler composition

2 files changed, 4 insertions, 2 deletions

diff --git a/src/Hakyll/Core/Compiler/Internal.hs b/src/Hakyll/Core/Compiler/Internal.hs
index 6737b6a..be78412 100644
--- a/src/Hakyll/Core/Compiler/Internal.hs
+++ b/src/Hakyll/Core/Compiler/Internal.hs
@@ -69,7 +69,7 @@ instance Applicative (Compiler a) where
 
 instance Category Compiler where
     id = Compiler (return S.empty) return
-    (Compiler d1 j1) . (Compiler d2 j2) =
+    ~(Compiler d1 j1) . ~(Compiler d2 j2) =
         Compiler (liftM2 S.union d1 d2) (j1 <=< j2)
 
 instance Arrow Compiler where
diff --git a/src/Hakyll/Core/Util/Arrow.hs b/src/Hakyll/Core/Util/Arrow.hs
index 49cbf2b..dfcb7da 100644
--- a/src/Hakyll/Core/Util/Arrow.hs
+++ b/src/Hakyll/Core/Util/Arrow.hs
@@ -7,6 +7,8 @@ module Hakyll.Core.Util.Arrow
     , mapA
     ) where
 
+import Prelude hiding (id)
+import Control.Category (id)
 import Control.Arrow ( Arrow, ArrowChoice, (&&&), arr, (>>^), (|||)
                      , (>>>), (***)
                      )
@@ -30,7 +32,7 @@ unitA = constA ()
 mapA :: ArrowChoice a
      => a b c
      -> a [b] [c]
-mapA f = arr listEither >>> arr id ||| (f *** mapA f >>> arr (uncurry (:)))
+mapA f = arr listEither >>> id ||| (f *** mapA f >>> arr (uncurry (:)))
   where
     listEither []       = Left []
     listEither (x : xs) = Right (x, xs)