title: How to make a REAL sleep() in JavaScript?
body: <p>I know there are many methods like setTimeout, but I just want a REAL one.</p>
  
  <p>I'm using JavaScript to write a compiler, and I have to find out a way to implement the sleep() function.
  I know that buggy loop way, it's not what I want.</p>
  
  <p>Thanks.</p>