On Wed, Feb 20, 2019 at 5:08 PM Jon Zeppieri <zeppi...@gmail.com> wrote:
>
> (define (reverse-hash h)
> (for*/fold ([result (hash)])
> ([(score letters) (in-hash h)]
> [letter (in-list letters)])
> (hash-set result letter score)))
>
>
As with Jens's answer, we can use `for*/hash` here, as well, and make this
slightly shorter:
(define (reverse-hash h)
(for*/hash ([(score letters) (in-hash h)]
[letter (in-list letters)])
(values letter score)))
`for*/hash` is really a specialized version of `for*/fold`, which handles
the hash accumulator for you. The `(values letter score)` expression in the
body indicates how the (implicit) accumulator will be updated.
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