Commit before generalising picture transformation to alternative

src/Picture/Data.hs

@@ -4,6 +4,8 @@ module Picture.Data
     where
 import Geometry.Data
 
+import Data.Foldable
+
 --import Data.Monoid
 --import Data.Traversable
 --import qualified Data.Foldable as F
@@ -55,6 +57,7 @@ instance Foldable LTree where
 instance Functor LTree where
     fmap f (LBranches ts) = LBranches $ fmap (fmap f) ts
     fmap f (LLeaf x) = LLeaf (f x)
+    {-# INLINE fmap #-}
 
 data RTree a b
     = RBranches a [RTree a b]