@@ -1,4 +1,5 @@
11{-# LANGUAGE CPP #-}
2+{-# LANGUAGE DeriveFunctor #-}
23#if __GLASGOW_HASKELL__
34{-# LANGUAGE DeriveDataTypeable, StandaloneDeriving #-}
45#endif
@@ -43,7 +44,7 @@ import qualified Data.Map as M
4344import Data.Data
4445#endif
4546
46−data OMap k v = OMap !(Map k (Tag, v)) !(Map Tag (k, v))
47+data OMap k v = OMap !(Map k (Tag, v)) !(Map Tag (k, v)) deriving Functor
4748
4849-- | Values are produced in insertion order, not key order.
4950instance Foldable (OMap k) where foldMap f (OMap _ kvs) = foldMap (f . snd) kvs