var list = events[name] || (events[name] = [])

if(!events[name]){
    events[name]=[];
}
var list=events[name];

var stack;
  try {
    var up = new Error();
    throw up;
  } catch (e) {
    // IE won‘t set Error.stack until thrown
    stack = e.stack.split(‘\n‘);
  }

//  at Error (native) <- Here‘s your problem
//  at http://localhost:8000/_site/dist/sea.js:2:4334 <- What we want
//  at http://localhost:8000/_site/dist/sea.js:2:8386
//  at http://localhost:8000/_site/tests/specs/web-worker/worker.js:3:1

function requestFromWebWorker(url, callback, charset) {
    // Load with importScripts
    var error;
    try {
      importScripts(url);
    } catch (e) {
      error = e;
    }
    callback(error);
  }
  // For Developers
  seajs.request = requestFromWebWorker;

  // 通过script标签加载脚本
  function request(url, callback, charset) {
    var node = doc.createElement("script")

    if (charset) {
      var cs = isFunction(charset) ? charset(url) : charset
      if (cs) {
        node.charset = cs
      }
    }

    addOnload(node, callback, url)

    node.async = true
    node.src = url

    // For some cache cases in IE 6-8, the script executes IMMEDIATELY after
    // the end of the insert execution, so use `currentlyAddingScript` to
    // hold current node, for deriving url in `define` call
    currentlyAddingScript = node

    // ref: #185 & http://dev.jquery.com/ticket/2709
    baseElement ?
        head.insertBefore(node, baseElement) :
        head.appendChild(node)

    currentlyAddingScript = null
  }
  //添加加载完成之后的处理，包括报错、清除对象、移除dom等操作
  function addOnload(node, callback, url) {
    var supportOnload = "onload" in node

    if (supportOnload) {
      node.onload = onload
      node.onerror = function() {
        emit("error", { uri: url, node: node })
        onload(true)
      }
    }
    else {
      node.onreadystatechange = function() {
        if (/loaded|complete/.test(node.readyState)) {
          onload()
        }
      }
    }

    function onload(error) {
      // Ensure only run once and handle memory leak in IE
      node.onload = node.onerror = node.onreadystatechange = null

      // Remove the script to reduce memory leak
      // 添加了又去除掉
      if (!data.debug) {
        head.removeChild(node)
      }

      // Dereference the node
      node = null

      callback(error)
    }
  }

  // For Developers
  seajs.request = request

//定义module类
function Module(uri, deps) {
  //模块路径
  this.uri = uri
  //这是一个字符串数组，内容是该模块依赖模块的id列表
  this.dependencies = deps || []
  //这是该模块所依赖的模块的一个map key为id，value为Module对象
  this.deps = {} // Ref the dependence modules
  //模块状态
  this.status = 0
  //用来辅助load的一个数组，load完成后会删掉
  this._entry = []
}

var cachedMods = seajs.cache = {}

// 获取模块中依赖模块的uri数组
Module.prototype.resolve 
// 一个辅助模块load过程的函数
Module.prototype.pass
//加载并执行模块
Module.prototype.load
//模块加载完成后触发
Module.prototype.onload
//模块404时候触发
Module.prototype.error
//执行模块
Module.prototype.exec
//用来获取模块文件，每调用一次给一个缓存对象设置一个key value，value是一个函数，调用即开始加载文件

//通过id获取文件uri
Module.resolve = function(id, refUri)
//用来定义一个模块
Module.define= function (id, deps, factory)
//将id、依赖、 factory 、模块加载状态设置给缓存中的模块
Module.save= function(uri, meta)
////根据uri，从缓存中获取模块，或者以接收的uri和deps参数创建一个模块返回，并加入缓存
Module.get=function(uri, deps)
//用来加载并运行模块
Module.use = function(ids, callback, uri)