1 files changed, 13 insertions, 1 deletions
diff --git a/src/Array.hs b/src/Array.hs
index 8507544..ef9bb8d 100644
--- a/src/Array.hs
+++ b/src/Array.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE DataKinds #-}
+{-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE DeriveTraversable #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE KindSignatures #-}
@@ -6,10 +7,12 @@
 {-# LANGUAGE TupleSections #-}
 module Array where
 
+import Control.DeepSeq
 import Control.Monad.Trans.State.Strict
 import Data.Foldable (traverse_)
 import Data.Vector (Vector)
 import qualified Data.Vector as V
+import GHC.Generics (Generic)
 
 import Data
 
@@ -20,12 +23,20 @@ data Shape n where
 deriving instance Show (Shape n)
 deriving instance Eq (Shape n)
 
+instance NFData (Shape n) where
+  rnf ShNil = ()
+  rnf (sh `ShCons` n) = rnf n `seq` rnf sh
+
 data Index n where
   IxNil :: Index Z
   IxCons :: Index n -> Int -> Index (S n)
 deriving instance Show (Index n)
 deriving instance Eq (Index n)
 
+instance NFData (Index n) where
+  rnf IxNil = ()
+  rnf (sh `IxCons` n) = rnf n `seq` rnf sh
+
 shapeSize :: Shape n -> Int
 shapeSize ShNil = 1
 shapeSize (ShCons sh n) = shapeSize sh * n
@@ -51,7 +62,8 @@ enumShape sh = map (fromLinearIndex sh) [0 .. shapeSize sh - 1]
 
 -- | TODO: this Vector is a boxed vector, which is horrendously inefficient.
 data Array (n :: Nat) t = Array (Shape n) (Vector t)
-  deriving (Show, Functor, Foldable, Traversable)
+  deriving (Show, Functor, Foldable, Traversable, Generic)
+instance NFData t => NFData (Array n t)
 
 arrayShape :: Array n t -> Shape n
 arrayShape (Array sh _) = sh