gistfile1.clj

(def resource-agent
  (memoize
   (fn [url]
     (agent #{}
            :validator (fn [state] (set? state))
            :error-handler #(.log js/console "ERROR: " %1 %2)
            :error-mode :fail))))

;; now what's an agent? 

(def a (agent 0))

;; an agent is an entity that acts on behalf of some piece of data - currying functions sent to it and applying it on its state, returning an updated agent

(send a inc) 

;; you can get the value of an agent by deferencing it

@agent
1
(deref agent)
1

;; @ and deref are the same thing, @ is just sugar, notice how after we sent the agent the inc function, it's new value is 1