Hy implamentation of Clojure's awesome `future` call

future.clj

(import [multiprocessing.pool [ThreadPool]])

(defmacro future [code]
    (def t (gensym))
    (def pool (ThreadPool :processes 1))
    `(do
        (def ~t (pool.apply-async (fn [] ~code)))
      ~t))

usage:

=> (def my-thread (future (long-running-function)))
# some time passes
=> (.get my-thread)
"return value from long-running-function"

or simply,

=> (future (print "hy"))
<multiprocessing.pool.ApplyResult object at 0x7f946bff56a0>
"hy"