1 files changed, 6 insertions, 0 deletions
diff --git a/app/Pretty.hs b/app/Pretty.hs
index 8621a41..07b3296 100644
--- a/app/Pretty.hs
+++ b/app/Pretty.hs
@@ -36,6 +36,12 @@ instance Pretty String where
 instance Pretty Float where
   pretty = pretty . Diagram 1 . (: [])
 
+instance (Pretty a) => Pretty (Maybe a) where
+  pretty maybeA =
+    case maybeA of
+      Nothing -> Lit Nothing "n/a"
+      Just a -> pretty a
+
 data Diagram a = Diagram Int a deriving (Functor, Show)
 
 diagram :: Int -> a -> Diagram a