1 files changed, 14 insertions, 0 deletions
diff --git a/src/Script/Expr/Class.hs b/src/Script/Expr/Class.hs
index 20a92b4..810b0c8 100644
--- a/src/Script/Expr/Class.hs
+++ b/src/Script/Expr/Class.hs
@@ -39,6 +39,10 @@ data ExprListUnpacker a = forall e. ExprType e => ExprListUnpacker (a -> [e]) (P
 data ExprEnumerator a = ExprEnumerator (a -> a -> [a]) (a -> a -> a -> [a])
 
 
+instance ExprType () where
+    textExprType _ = "Unit"
+    textExprValue () = "()"
+
 instance ExprType Integer where
     textExprType _ = T.pack "integer"
     textExprValue x = T.pack (show x)
@@ -75,3 +79,13 @@ instance ExprType a => ExprType [a] where
     textExprValue x = "[" <> T.intercalate ", " (map textExprValue x) <> "]"
 
     exprListUnpacker _ = Just $ ExprListUnpacker id (const Proxy)
+
+instance ExprType a => ExprType (Maybe a) where
+    textExprType _ = textExprType @a Proxy <> "?"
+    textExprValue (Just x) = textExprValue x
+    textExprValue Nothing = "Nothing"
+
+instance (ExprType a, ExprType b) => ExprType (Either a b) where
+    textExprType _ = textExprType @a Proxy <> "|" <> textExprType @b Proxy
+    textExprValue (Left x) = "Left " <> textExprValue x
+    textExprValue (Right x) = "Right " <> textExprValue x