DeferredFnStack

Q = require 'q'

DeferredFnStack = (fn) ->
  stack = Q.when()

  return ->
    dfd = Q.defer()
    stack = stack.fin -> Q.when(fn()).then(dfd.resolve, dfd.reject)
    dfd.promise

###
  USAGE
###

asyncPromise = (value) ->
  dfd = Q.defer()

  resolve = ->
    dfd.resolve(value)

  setTimeout resolve, 500

  dfd.promise


fn = DeferredFnStack ->
  Q.resolve('Hello World!')
  .then asyncPromise
  .then asyncPromise


fn().then (value) -> console.log value
fn().then (value) -> console.log value
fn().then (value) -> console.log value

###
  Outputs 3 times 'Hello World!' with 1000ms interval
###