(module let-optionals mzscheme (provide let-optionals*)

(define-syntax let-optionals*
  (syntax-rules ()
    ((_ opt-ls () body ...)
     (let () body ...))
    ((_ (expr ...) vars body ...)
     (let ((tmp (expr ...)))
       (let-optionals* tmp vars body ...)))
    ((_ tmp ((var default) . rest) body ...)
     (let ((var (if (pair? tmp) (car tmp) default))
           (tmp2 (if (pair? tmp) (cdr tmp) '())))
       (let-optionals* tmp2 rest body ...)))
    ((_ tmp tail body ...)
     (let ((tail tmp))
       body ...))
    ))

)