myblog/node_modules/core-js/modules/core.number.iterator.js

'use strict';
require('./$.iter-define')(Number, 'Number', function(iterated){
  this._l = +iterated;
  this._i = 0;
}, function(){
  var i    = this._i++
    , done = !(i < this._l);
  return {done: done, value: done ? undefined : i};
});