xtm-closure-doc   macro

(define-macro (xtm-closure-doc name)
  `(let ((docstring (impc:ti:get-closure-docstring ,name))
         (types (impc:ti:get-closure-type ,name))
         (form (impc:ti:get-closure-body ,name)))
     (if docstring
         (list (cdr docstring) (cdr types) (cdr form))
         (if types
             (list '() (cdr types) (cdr form))
             (if form
                 (list '() '() (cdr form))
                 #f)))))