ZhihaoLau

function createIterator(items) {
  var i = 0;
  return {
    next: function() {
      // NZakas' way is really straight forward what 'done' and 'value' is.
      var done = (i >= items.length);
      var value = done ? undefined : items[i++];

      return {
        done: done,

ZhihaoLau

let promise = Promise.resolve('hello');

promise.then(function(data) {
  console.log(data);
});

// Or: ------------------------

let promise = Promise.reject('oops');

ZhihaoLau

var fs = require('fs');

function readFile(filename) {
  return new Promise(function(resolve, reject) {
    fs.readFile(filename, {encoding: 'utf8'}, function(err, data) {
      if (err) {
        reject(err);
        return;
      }
      resolve(data);

ZhihaoLau

function add(getX, getY, cb) {
  var x, y;
  getX(function(xVal) {
    x = xVal;
    if (y !== undefined) {
      cb(x + y);
    }
  });
  get(function(yVal) {

ZhihaoLau

// cause safari private mode do not support storage

if (typeof localStorage === 'object') {
  try {
    localStorage.setItem('localStorage', 1);
    localStorage.removeItem('localStorage');
  } catch (e) {
    Storage.prototype._setItem = Storage.prototype.setItem; 
    Storage.prototype.setItem = function() {};
    alert('你的浏览器似乎不支持本地缓存，如果你是Safari用户，请关闭“无痕浏览”模式');

ZhihaoLau

.DS_Store
*.log
dist
node_modules
.sass-cache
.svn
.gitmodules

ZhihaoLau

// pre es5
function isEmpty(myObject) {
  for (var key in myObject) {
    if (myObject.hasOwnProperty(key)) {
      return false
    }
  }
  
  return true 
}  

ZhihaoLau

// accept a array of reducers
const combineReducers = (reducers) => {
  // returns a huge reducer, looks like below gist
  return (state = {}, action) => {
    return Object.keys(reducers).reduce(
      (nextState, key) => {
        nextState[key] = reducers[key](
          state[key],
          action
        )

ZhihaoLau

const createStore = (reducer) => {
  // only this place create the one and only state
  let state
  let listeners = []
  
  const getState = () => state
  
  const dispatch = (action) => {
    // change state only by dispatching an action
    state = reducer(state, action)

ZhihaoLau

function* fibonacci() {
  let [prev, curr] = [0, 1];
  
  // using deconstruct feature implement reducer, really cool...
  for (;;) {
    [prev, curr] = [curr, curr + prev];
    yield curr;
  }
}