[racket-dev] [plt] Push #28137: master branch updated

From: Sam Tobin-Hochstadt (samth at cs.indiana.edu)
Date: Tue Feb 4 18:15:08 EST 2014

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.


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