In Overtone we have the same situation, where we return a promise
representing a server response and sometimes we want to timeout if the
response never arrives.  This is what we use:

(defn await-promise!
  ([prom] (await-promise prom REPLY-TIMEOUT))
  ([prom timeout]
     (.get (future @prom) timeout TimeUnit/MILLISECONDS)))

(We have another version without the exclamation mark that
returns :timeout rather than throwing an exception when timed out.)

I agree with you though, that something along these lines should be
built-in.  I was surprised to find that there was no way to block on a
promise with a timeout, as it seems like such a typical requirement
for almost anything you might be promised.

-Jeff

On Mar 9, 1:12 pm, Sean Allen <s...@monkeysnatchbanana.com> wrote:
> Yesterday I was writing a bit of code that needs to wait for an
> external event to happen but if it doesn't happen with X amount of
> time,
> to timeout with an error.
>
> Is there a library to handle this? I know you can do it with a future
> and if you google the general idea, there are a few blog posts, stack
> overflow questions etc that all have the same basic solution. It seems
> like such a common thing to do that there would be a standard
> function/macro out there for it rather than everyone rolling their
> own. I couldn't however find one.
>
> Does one exist? If yes, pointer in the right direction.
>
> Thanks,
> Sean

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