gen-promise-foo.js

'use strict'

let co = require('co')

function * list (array, subdivision) {
  let deferred = Promise.defer()
  let marker = 0;
  let stop = marker + subdivision
  let max = A.length
  let to = Math.random() * 1000 | 0

  while (marker < max) {
    setTimeout(() => {
      let sliced = array.slice(marker, stop)
      marker += subdivision
      stop = marker + subdivision
      deferred.resolve(sliced)
      deferred = Promise.defer()
    }, to)
    yield deferred.promise
  }
}


co(function * () {
  let array = new Array(16).fill(1).map((_, i) => i + 1)
  let it = list(array, 4)
  let a = yield it.next()
  let b = yield it.next()
  let c = yield it.next()
  let d = yield it.next()
  console.log(a, b, c, d)
})
.then(console.log)
.catch(console.log)