Confused by :chan-opts

chan_opts.clj

(require '[clojure.core.async.flow :as flow]
         '[clojure.core.async.flow-monitor :as mon])

(defn tap-n-drop [x] (tap> x) nil)

;; chan-opts on out channel seem to be ignored
;; override buf size not visible in flow-monitor
;; transform not applied
(def flow
  "Simple flow connecting credit-core to an event sync that taps"
  (flow/create-flow
   {:procs {:source {:proc (-> identity flow/lift1->step flow/process)
                     :chan-opts {:out {:buf-or-n 11
                                       :xform (map (fn [x] (str "Saw " x)))}}}
            :sink {:proc (-> #'tap-n-drop flow/lift1->step flow/process)}}
    :conns [[[:source :out] [:sink :in]]]}))

;; chan-opts on in channel seem to work
;; override buf size visible in flow-monitor
;; transform applied
(def flow
  "Simple flow connecting credit-core to an event sync that taps"
  (flow/create-flow
   {:procs {:source {:proc (-> identity flow/lift1->step flow/process)}
            :sink {:proc (-> #'tap-n-drop flow/lift1->step flow/process)
                   :chan-opts {:in {:buf-or-n 11
                                    :xform (map (fn [x] (str "Saw " x)))}}}}
    :conns [[[:source :out] [:sink :in]]]}))

;; start
(do 
  (flow/start flow)
  (flow/resume flow)
  (def server (mon/start-server {:flow flow})))

;; test
@(flow/inject flow [:sink :in] ["hello"])

;; stop
(do 
  (mon/stop-server server)
  (flow/stop flow))