#xyzzy

gistfile1.cl

(defmacro define-tco-function (name (&rest lambda-list) &body body)
  (let ((continue (gensym "continue"))
        (vals (mapcar #'(lambda (x) (if (consp x) (car x) x))
                      (remove-if (lambda (x) (member x lambda-list-keywords))
                                 lambda-list))))
    `(defun ,name ,lambda-list
       (macrolet ((,name (&rest args)
                    (list 'progn
                          (list 'multiple-value-setq ',vals (cons 'values args))
                          (list 'go ',continue))))
         (tagbody
           ,continue
           (return-from
               ,name
             (progn ,@body)))))))

引数のラムダリストの処理は手抜き。