From ebfbdcd09b92a55b6c9f5a1f7feaa4f98c2236ba Mon Sep 17 00:00:00 2001
From: joe <joe@jerkface.net>
Date: Tue, 12 Aug 2014 16:04:01 -0400
Subject: IntMapClass experiment

---
 IntMapClass.hs | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 IntMapClass.hs

(limited to 'IntMapClass.hs')

diff --git a/IntMapClass.hs b/IntMapClass.hs
new file mode 100644
index 0000000..49e1125
--- /dev/null
+++ b/IntMapClass.hs
@@ -0,0 +1,41 @@
+{-# LANGUAGE CPP,
+             FlexibleContexts,
+             MultiParamTypeClasses,
+             GeneralizedNewtypeDeriving,
+             DeriveDataTypeable #-}
+module IntMapClass where
+
+import qualified Data.IntMap.Strict as IntMap
+import Data.IntMap.Strict ( IntMap )
+import Data.Typeable ( Typeable )
+import Data.Data     ( Data )
+import Data.Foldable ( Foldable )
+import Data.Traversable ( Traversable )
+import Data.Monoid   ( Monoid )
+import Control.DeepSeq ( NFData )
+#if MIN_VERSION_base(4,7,0)
+import Data.Coerce
+#else
+class Coercible a b where coerce :: a -> b
+#endif
+
+newtype IMap k a = IMap (IntMap a)
+ deriving
+    ( Functor
+    , Typeable
+    , Foldable
+    , Traversable
+    , Eq
+    , Data
+    , Ord
+    , Read
+    , Show
+    , Monoid
+    , NFData
+    )
+
+adapt_m_k :: Coercible k Int => (IntMap a -> Int -> x) -> IMap k a -> k -> x
+adapt_m_k f (IMap m) k = f m (coerce k)
+
+(!) :: Coercible k Int => IMap k a -> k -> a
+(!) = adapt_m_k (IntMap.!)
-- 
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