engedits

eng = document.querySelectorAll('.engundefined')
var reduce_eng_cond = false
do {
  reduce_eng = false
  setTimeout(reduceEng,1000)
} while (reduce_eng_cond === true)

function reduceEng(){
  [].forEach.call(eng, function(el){
    var txt = el.textContent
    if (txt.length -1 >= 0) {
      el.textContent = txt.substr(0, el.textContent.length - 1)
      reduce_eng_cond = true
    }
  })
}

eng = document.querySelectorAll('.engundefined')
function doloop(job) {
  job().then(function(bool){
    if (bool) {
      return doloop(job)
    }
  })
}
function main(){
  return wait_(1).then(reduceEng_)
}
function wait_(s) {
  // s: seconds, number
  var ms = s * 1000
  return new Promise(function(resolve, reject) {
    setTimeout(function() {
      resolve(s)
    }, ms)
  });
}

function reduceEng_(){
  var reduce_eng_cond = false
  Array.prototype.forEach.call(eng, function(el){
    var txt = el.textContent
    if (txt.length -1 >= 0) {
      el.textContent = txt.substr(0, el.textContent.length - 1)
      reduce_eng_cond = true
    }
  })
  return Promise.resolve(reduce_eng_cond)
}

doloop(main)