This is super cool indeed. Now I feel stupid.

On Wed, Dec 4, 2019 at 2:56 PM Matthew Butterick <m...@mbtype.com> wrote:

>
> On Dec 4, 2019, at 2:39 PM, 'Joel Dueck' via Racket Users <
> racket-users@googlegroups.com> wrote:
>
> So it seems easy to match "*at least *N identical elements".
> But is there a method for matching "*no more than *N identical elements"?
>
>
> ?
>
>
> #lang racket
> (require rackunit)
>
> (define (super-cool? lst)
>   (match lst
>     [(and (list* _ ... a a _)
>           (not (list* _ ... a a a _))) #t]
>     [_ #f]))
>
> (check-true (super-cool? '(1 1 4)))
> (check-false (super-cool? '(1 1 1 4)))
>
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