es6 fibonaci generator

generator_simple.harmony.js

var fibo = function *(){
  var a = 0,
      b = 1;
  yield a;
  yield b;

  while(true){
    var next = a + b;
    yield next;
    a = b;
    b = next;
  }

};

var fiboGenerator = fibo();
var current = null;
while(!(current = fiboGenerator.next()).done){
  console.log(current.value);
}