[racket-dev] [plt] Push #28137: master branch updated
On Tue, Feb 4, 2014 at 6:12 PM, <asumu at racket-lang.org> wrote:
>
> + ;; Note: in practice it's unlikely that the second pattern will ever come up
> + ;; because the sequence number for '() will be low and the union will
> + ;; be sorted by sequence number. As a paranoid precaution, however,
> + ;; we will match against both patterns here.
> + (syntax/loc stx (or (Mu: var-pat (Union: (list (Value: '()) (Pair: elem-pat (F: var-pat)))))
> + (Mu: var-pat (Union: (list (Pair: elem-pat (F: var-pat)) (Value: '()))))))])))
Let's just make this a documented assumption, and save ourselves all some pain.
Sam