Using ECS lib for getting rid of deftypes/defrecords/defprotocols about component HOT 2 CLOSED

; ns com.stuartsierra.component

(defsystem start
  "Begins operation of this component. Synchronous, does not return
  until the component is started. Returns an updated version of this
  component."
  [component])

(defsystem stop
  "Ceases operation of this component. Synchronous, does not return
  until the component is stopped. Returns an updated version of this
  component."
  [component])

; ns com.stuartsierra.component-test

(defcomponent :d {:keys [my-c b] :as this}
  (start [_]
    (log 'd.start this)
    (assert (started? b))
    (assert (started? my-c))
    (assoc this ::started? true))
  (stop [_]
    (log 'd.stop this)
    (assert (started? b))
    (assert (started? my-c))
    (assoc this ::started? false)))

(defcomponent :e {:keys [] :as this}
  (start [_]
    (log 'e.start this)
    (assoc this ::started? true))
  (stop [_]
    (log 'e.stop this)
    (assoc this ::started? false)))

(defn system-1 []
  ; deliberately scrambled order
  {:e {}
   :c (component/using {} [:a :b])
   :b (component/using {} [:a])
   :d (component/using {}
                       {:b :b
                        :my-c :c})
   :a {}})