> > So, if a list whose first element is a vector is provided after a get or a > put in alt!, then that's treated as the binding form/code to be executed if > that succeeds, but if a non-list is provided, then that is treated as a > value to return if that action was taken (and that value is evaluated > before any operation happens)? > > I'm not sure about the evaluation order, but I bet you can come up with an experiment to test it :)
Eric > On Friday, August 15, 2014 8:35:05 AM UTC-4, Daniel Solano Gómez wrote: >> >> On Thu Aug 14 19:04 2014, dgrnbrg wrote: >> > You're all right--that was a cut & paste error. I meant that I see this >> > behavior with alt!!, not alts! >> >> With alt!!, it should probably be something like: >> >> (let [result (alt!! [[inner-chan e]] ([v] (if v >> :put-a-value >> :channel-closed)) >> :default :failed-to-put >> :priority true)] >> (println result)) >> >> I hope this helps. >> >> Sincerely, >> >> Daniel >> >> > >> > On Thursday, August 14, 2014 3:31:45 PM UTC-4, Ghadi Shayban wrote: >> > > >> > > What Daniel said. The call is incorrect, its args are alt-shaped, >> but it >> > > calls alt*s*. >> > > >> > > alt is the macro that is shaped like cond. >> > > alts is the function that takes a vector >> > > >> > > Both take splatted options at the end. >> > > >> > > Can never use single bang* except within go.* >> > > >> > > go => ! >> > > thread => !! >> > > >> > > Unfortunately if the two are confused, the exception will happen... >> > > probably elsewhere. >> > > >> > > On Thursday, August 14, 2014 2:46:22 PM UTC-4, Eric Normand wrote: >> > >> >> > >> Hi there, >> > >> >> > >> The :default option is for a *value* that should be returned if none >> of >> > >> the channels are available. The expression is evaluated *before* the >> > >> async/alts! call happens (just like normal parameters). >> > >> >> > >> I think you are misunderstanding alts!. It should be used like this >> > >> >> > >> (let [[val ch] (async/alts! [[inner-chan e]] :default :default)] >> > >> (if (= :default val) >> > >> (println "inner-chan was not ready") >> > >> (if val >> > >> (println "did the put to inner-chan") >> > >> (println "inner-chan is closed")))) >> > >> >> > >> I hope that helps. Let me know if you have any more questions. >> > >> >> > >> Eric >> > >> >> > >> On Thursday, August 14, 2014 11:03:01 AM UTC-5, dgrnbrg wrote: >> > >>> >> > >>> When I use alts!, it seems that both the put and :default action >> run >> > >>> every time. I've included the code sample below: >> > >>> >> > >>> (let [inner-chan (async/chan (async/buffer 1000)) >> > >>> mult (async/mult inner-chan) >> > >>> (async/thread >> > >>> (while true >> > >>> (let [e (.take linked-blocking-queue)] >> > >>> (async/alts! >> > >>> [[inner-chan e]] (println "did the put") >> > >>> :default (println "failed to put") >> > >>> :priority true))))) >> > >>> >> > >>> >> > >>> Elsewhere in the code, I tap the mult before I start putting >> elements >> > >>> onto the linked-blocking-queue. For every element I put onto the >> LBQ, I see >> > >>> both messages: "did the put" and "failed to put". What is going on >> here? >> > >>> >> > >> >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups "Clojure" group. >> > To post to this group, send email to clo...@googlegroups.com >> > Note that posts from new members are moderated - please be patient with >> your first post. >> > To unsubscribe from this group, send email to >> > clojure+u...@googlegroups.com >> > For more options, visit this group at >> > http://groups.google.com/group/clojure?hl=en >> > --- >> > You received this message because you are subscribed to the Google >> Groups "Clojure" group. >> > To unsubscribe from this group and stop receiving emails from it, send >> an email to clojure+u...@googlegroups.com. >> > For more options, visit https://groups.google.com/d/optout. >> > -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
