gistfile1.clj

(ns asdf
  (:require [clojure.core.async :as async :refer [<! <!! >! >!! chan go]]))

(defn promise-chan [src-chan]
  (let [c (chan 1)]
    (go
      (let [x (<! src-chan)]
        (loop []
          (>! c x)
          (recur))))
    c))

(defmacro go-promise [& body]
  `(promise-chan (go ~@body)))

(let [p (go-promise 123)]
  (assert (= (<!! p) (<!! p) (<!! p)))
  (<!! p))