1 files changed, 7 insertions, 2 deletions
diff --git a/ast.hs b/ast.hs
index e3db600..f566335 100644
--- a/ast.hs
+++ b/ast.hs
@@ -31,6 +31,8 @@ data Type = TypeInt Int
           | TypeDouble
           | TypePtr Type
           | TypeName Name
+          | TypeFunc Type [Type]
+          | TypeVoid
   deriving (Show, Eq)
 
 data Literal = LitInt Integer
@@ -63,7 +65,7 @@ data Statement
     | StAssignment Name Expression
     | StIf Expression Statement Statement
     | StWhile Expression Statement
-    | StReturn Expression
+    | StReturn (Maybe Expression)
   deriving (Show)
 
 
@@ -116,6 +118,8 @@ instance PShow Type where
     pshow TypeDouble = "double"
     pshow (TypePtr t) = concat ["ptr(", pshow t, ")"]
     pshow (TypeName n) = n
+    pshow TypeVoid = "void"
+    pshow (TypeFunc ret args) = concat ["func ", pshow ret, "("] ++ intercalate "," (map pshow args) ++ ")"
 
 instance PShow Literal where
     pshow (LitInt i) = pshow i
@@ -164,4 +168,5 @@ instance PShow Statement where
     pshow (StIf c t@(StBlock _) e) = concat ["if (", pshow c, ") ", pshow t, " else ", pshow e]
     pshow (StIf c t e) = concat ["if (", pshow c, ") ", pshow t, "\nelse ", pshow e]
     pshow (StWhile c s) = concat ["while (", pshow c, ") ", pshow s]
-    pshow (StReturn e) = concat ["return ", pshow e, ";"]
+    pshow (StReturn Nothing) = "return;"
+    pshow (StReturn (Just e)) = concat ["return ", pshow e, ";"]