an implementation of rob pike's parallel search slide in oia

oia_csp.js

oia(lets [go chan put take timeout alts] (require 'js-csp/lib/csp') (do

  (fn fake [kind] 
    (fn [c query] 
      (go (gen [] 
        (yield (take (timeout (js Math.random()*200))))
        (yield (put c [kind query]))))))

  (def web1 (fake :web1))
  (def web2 (fake :web2))
  (def image1 (fake :image1))
  (def image2 (fake :image2))
  (def video1 (fake :video1))
  (def video2 (fake :video2))

  (fn fastest [query replicas]
    (let [c (chan)]
      (.forEach replicas (fn [replica] (replica c query))) c))

  (fn google [query] 
    (let [c (chan) t (timeout 100) sink (chan)]
      (go (gen [] 
        (yield (put c (yield (take (fastest query [$ web1 web2])))))))
      (go (gen [] 
        (yield (put c (yield (take (fastest query [$ image1 image2])))))))
      (go (gen [] 
        (yield (put c (yield (take (fastest query [$ video1 video2])))))))
      
      (go (gen []
        (def res [$])
        (dotimes 3 
          (.push res (get (yield (alts [$ c t])) :value 'timed out')))
        (yield (put sink res))))
      
      sink))
  
  (go (gen []
    (prn (yield (take (google 'oia'))))))))