Connection as a Sequence sleep retry on nil Lets say you have a connection that you want to stream results from. The connection can also return zero data in which case you would want to sleep and retry until data is available. A complicated solution would be to do this with a loop recur but a more elegant pattern can be created using map and fil…

gistfile1.clj

;for testing purposes lets simulate a connection that will return nil or 1 
(defn connect-and-get [] (rand-nth [nil 1 1 1 nil 1 nil 1 nil]))

(def select-data (repeatedly connect-and-get))

(defn sleep-while-nil [ts s]
       (filter (complement nil?) (map (fn [x] (if-not x (Thread/sleep ts)) x) s)))

(take 10 (sleep-while-nil 100 select-data))
;;(1 1 1 1 1 1 1 1 1 1)

thanks for this. interesting use of complement inside the filter