================================================================================
consym: valid
================================================================================

data A = Int :+ Int

---

(haskell
 (adt
  (type)
  (constructors
   (data_constructor_infix
    (type_name (type))
    (constructor_operator)
    (type_name (type))))))


================================================================================
consym: error: ::
================================================================================

data A = Int :: Int

---

(haskell (adt (type) (constructors (data_constructor (constructor) (ERROR) (type_name (type))))))
