Question on nested expressions

[Shiwei Weng]

Hi all, I write a simple example for my question.

If I want to keep the Expr to be (e* ... e), then 

in the `de-Expr`, is there any way to deal with `e*` and `e0` together, 

(I hope code similar to `(map de-Expr (append e* (list e0))` but I try several ways, neither of them works.

```racket

#lang nanopass

(define-language L

  (Expr (e)

    (e* ... e)

    (ok f))

  (Foo (f)

    (bar)

    (boo)))

(define-pass bar-boo : L(e) -> L ()

  (de-Expr : Expr (e env) -> Expr ()

    [(,e* ... ,e0)

     (let* ([ne* (map de-Expr e*)] 

             [ne0 (de-Expr e0)])

       `(,ne* ... ,ne0))]

    [(ok ,[f])

     `(ok ,f)])

   (de-bar : Foo (f) -> Foo ()

    [(bar)

     `(boo)])

)

(define-parser parse-L L)

(bar-boo

 (parse-L

  `(

    (ok (bar))

    (ok (bar))

    (ok (bar))

    )

  )

)

```

best,

shiwei