fix for nhc98 build

diff --git a/Data/IntMap.hs b/Data/IntMap.hs
index 6c795aa..9b897a3 100644 (file)
--- a/Data/IntMap.hs
+++ b/Data/IntMap.hs
@@ -165,6 +165,7 @@ import Data.Monoid (Monoid(..))
 import Data.Typeable
 import Data.Foldable (Foldable(foldMap))
 import Control.Monad ( liftM )
+import Control.Arrow (ArrowZero)
 {-
 -- just for testing
 import qualified Prelude