interned symbols

app/Gyehoek/Scheme/Syntax.hs

@@ -40,6 +40,7 @@ data Prim e
   | PrimConsP e
   | PrimIntegerP e
   | PrimWrite e
+  | PrimNewline
   deriving (Show, Generic, Functor, Foldable, Traversable)
 
 instance Each (Prim e) (Prim e') e e'
@@ -90,9 +91,11 @@ instance SexpIso a => SexpIso (Prim a) where
     $ With (. unop "cons?")
     $ With (. unop "integer?")
     $ With (. unop "write")
+    $ With (. nullop "newline")
     $ End
     where
       primname = ("prim:" <>)
+      nullop s = list $ el (sym (primname s))
       unop s = list $ el (sym (primname s)) >>> el sexpIso
       binop s = list $ el (sym (primname s)) >>> el sexpIso >>> el sexpIso