monads! (kind of)

gistfile1.clj

;; Examples based on code in https://github.com/ibdknox/jayq/tree/let-deferred

;; sugar for do-> ajax-m
(let-ajax  [a  {:url "http://localhost:8000/1.json"
                :dataType :json}
            b  {:dataType :json :url "http://localhost:8000/2.json"}]
           (utils/log a)
           (utils/log b))

;; sugar for do-> deferred-m
(let-deferred
    [a (jq/ajax "http://localhost:8000/1.json")
     :let [foo "bar"]
     b (jq/ajax "http://localhost:8000/2.json")]
  (utils/log a)
  (utils/log b)
  (utils/log foo))

(do-> jq/deferred-m
      [a (jq/ajax "http://localhost:8000/1.json"))
       :let [c (js/Date.)]
       :when (== a 2)
       b (jq/ajax "http://localhost:8000/2.json")
       c (jq/ajax "http://localhost:8000/3.json")]
      (concat a b c))

;; definitions 
(def deferred-m
  {:return $when
   :bind (fn [x f]
           (let [dfd ($deferred)]
             (done x (fn [v]
                       (done (f v) (partial resolve dfd))))
             (promise dfd)))})

(def ajax-m
  {:return identity
   :bind (fn [x f] (ajax (assoc x :success f)))})


;; generated code for the do-> deferred-m example:

var G__8784 = (new cljs.core.Keyword("\ufdd0'bind")).call(null, jayq.core.deferred_m);
var G__8785 = (new cljs.core.Keyword("\ufdd0'return")).call(null, jayq.core.deferred_m);
G__8784.call(null, jayq.core.ajax.call(null, "http://localhost:8000/1.json"), function(a) {
  var c = new Date;
  if(a === 2) {
    return G__8784.call(null, jayq.core.ajax.call(null, "http://localhost:8000/2.json"), function(b) {
      return G__8784.call(null, jayq.core.ajax.call(null, "http://localhost:8000/3.json"), function(c__$1) {
        return G__8785.call(null, cljs.core.concat.call(null, a, b, c__$1))
      })
    })
  }else {
    return G__8785.call(null, a === 2)
  }
});