Allow for assigning attach items orientations

src/Dodge/Data/DoubleTree.hs

@@ -49,6 +49,11 @@ instance Foldable DoubleTree where
 instance Functor (LabelDoubleTree b) where
     fmap f (LDT x l r) = LDT (f x) (fmap (second $ fmap f) l) (fmap (second $ fmap f) r)
 
+instance Bifunctor LabelDoubleTree where
+    second = fmap
+    first f (LDT x l r) = LDT x (map (first f . second (first f)) l)
+        (map (first f . second (first f)) r)
+
 makeLenses ''DoubleTree
 makeLenses ''LabelDoubleTree
 deriveJSON defaultOptions ''DoubleTree