Use QuickCheck's 'Fun' when testing insertWith and insertWithKey.

We use apply instead of apply2 and apply3 because the latter two are only
available in recent QuickCheck versions. We also use (Int, Int, Int) -> Int
for the function for insertWithKey so we don't need to add additional instances
to Key to work with `Fun`.

Author: m-renaud

tests/HashMapProperties.hs

@@ -18,6 +18,7 @@ import qualified Data.HashMap.Lazy as HM
 #endif
 import qualified Data.Map as M
 import Test.QuickCheck (Arbitrary, Property, (==>), (===))
+import Test.QuickCheck.Function (Fun, apply)
 import Test.Framework (Test, defaultMain, testGroup)
 import Test.Framework.Providers.QuickCheck2 (testProperty)
 
@@ -147,12 +148,14 @@ pDeleteCollision k1 k2 k3 idx = (k1 /= k2) && (k2 /= k3) && (k1 /= k3) ==>
         | which == 2 = k1
         | otherwise = error "Impossible"
 
-pInsertWith :: Key -> [(Key, Int)] -> Bool
-pInsertWith k = M.insertWith (+) k 1 `eq_` HM.insertWith (+) k 1
+pInsertWith :: Fun (Int, Int) Int -> Key -> [(Key, Int)] -> Bool
+pInsertWith f k =
+  M.insertWith f' k 1 `eq_` HM.insertWith f' k 1
+  where f' = curry . apply $ f
 
-pInsertWithKey :: Key -> [(Key, Int)] -> Bool
-pInsertWithKey k = M.insertWithKey f k 1 `eq_` HM.insertWithKey f k 1
-  where f (K k') a b = if k' >= 0 then a else b
+pInsertWithKey :: Fun (Int, Int, Int) Int -> Key -> [(Key, Int)] -> Bool
+pInsertWithKey f k = M.insertWithKey f' k 1 `eq_` HM.insertWithKey f' k 1
+  where f' k' v1 v2 = apply f (unK k', v1, v2)
 
 pAdjust :: Key -> [(Key, Int)] -> Bool
 pAdjust k = M.adjust succ k `eq_` HM.adjust succ k