(define impc:ti:get-closure-or-nativefunc-arg-types
  (lambda (closure-or-nativefunc-name)
    (let ((res (impc:ti:get-closure-arg-types closure-or-nativefunc-name)))
      (if (or (not res) (null? res))
          (impc:ti:get-nativefunc-arg-types closure-or-nativefunc-name)
          res))))