I think you're really talking about reductions, not reduce. In sequence form, like:
user=> (reductions + [0 1 2 3 4 5]) (0 1 3 6 10 15) There is not currently a reductions transducer although there is a ticket proposing to add one: http://dev.clojure.org/jira/browse/CLJ-1903 You don't have to wait for that of course, you could just use the reductions transducer defined in that ticket. (require '[clojure.core.async :as a :refer [<!!]]) (defn reductions-with ([f init] (fn [rf] (let [state (volatile! init)] (fn ([] (rf)) ([result] (rf result)) ([result input] (if (reduced? @state) @state (rf result (unreduced (vswap! state f input)))))))))) ;; create the summarizing chan (def ch (a/chan 1 (reductions-with + 0))) ;; in background thread pump numbers in (future (a/onto-chan ch (range 6))) ;; drain results (<!! (a/reduce conj [] ch)) ;;=> [0 1 3 6 10 15] On Wednesday, August 10, 2016 at 8:26:39 AM UTC-5, JokkeB wrote: > > Hi, > > I'm wondering why reduce doesn't return a transducer like map does. For > example I'd like to this: > > (async/chan 1 (reduce +)) > > I could use async/reduce but it doesn't provide a result before the source > channel closes, I want to have a streaming result. > > What is the philosophy behind not having reduce return a transducer when > no collection is passed to it? How should I go about doing a streaming > stateful reducer, like in my example? > -- 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.
