function createInjector(modulesToLoad) {var INSTANTIATING = {},providerSuffix = 'Provider',path = [],loadedModules = new HashMap(),    //一个hash对象，用来存储已经加载过的模块providerCache = {$provide: {provider: supportObject(provider),factory: supportObject(factory),service: supportObject(service),value: supportObject(value),constant: supportObject(constant),decorator: decorator}},providerInjector = (providerCache.$injector =createInternalInjector(providerCache, function() {    //创建一个内部的注册器实例对象，它跟下面的注册器实例对象拥有相同的方法，只是它们操作的参数不一样，这个操作的是providerCache和抛出错误的回调函数。throw $injectorMinErr('unpr', "Unknown provider: {0}", path.join(' <- '));})),instanceCache = {},instanceInjector = (instanceCache.$injector =createInternalInjector(instanceCache, function(servicename) {     //创建一个内部的注册器实例对象，并返回此注册器实例对象，此对象有几个方法，它的这几个方法里面有引用你通过createInternalInjector传进去的参数，因此，形成了闭包。var provider = providerInjector.get(servicename + providerSuffix);return instanceInjector.invoke(provider.$get, provider);}));    forEach(loadModules(modulesToLoad),     //加载初始化的模块function(fn) { instanceInjector.invoke(fn || noop); });return instanceInjector;   //返回注册器实例对象function supportObject(delegate) {return function(key, value) {if (isObject(key)) {forEach(key, reverseParams(delegate));} else {return delegate(key, value);}};}function provider(name, provider_) {assertNotHasOwnProperty(name, 'service');if (isFunction(provider_) || isArray(provider_)) {provider_ = providerInjector.instantiate(provider_);}if (!provider_.$get) {throw $injectorMinErr('pget', "Provider '{0}' must define $get factory method.", name);}return providerCache[name + providerSuffix] = provider_;}function factory(name, factoryFn) { return provider(name, { $get: factoryFn }); }function service(name, constructor) {return factory(name, ['$injector', function($injector) {return $injector.instantiate(constructor);}]);}function value(name, val) { return factory(name, valueFn(val)); }function constant(name, value) {assertNotHasOwnProperty(name, 'constant');providerCache[name] = value;instanceCache[name] = value;}function decorator(serviceName, decorFn) {var origProvider = providerInjector.get(serviceName + providerSuffix),orig$get = origProvider.$get;origProvider.$get = function() {var origInstance = instanceInjector.invoke(orig$get, origProvider);return instanceInjector.invoke(decorFn, null, {$delegate: origInstance});};}function loadModules(modulesToLoad){    //这里的modulesToLoad = ["ng", ["$provide",function($provide){ $provide.value("$rootElement", element); }]]。 var runBlocks = [], moduleFn, invokeQueue, i, ii;forEach(modulesToLoad, function(module) {    //针对每一个模块，执行此方法if (loadedModules.get(module)) return;    //如果此模块已经加载过了，就不用再次加载了，直接进行下一次循环去加载下一个模块loadedModules.put(module, true);try {if (isString(module)) {    //ng模块进入到这里   moduleFn = angularModule(module);   //得到ng模块的实例对象runBlocks = runBlocks.concat(loadModules(moduleFn.requires)).concat(moduleFn._runBlocks);for(invokeQueue = moduleFn._invokeQueue, i = 0, ii = invokeQueue.length; i < ii; i++) {var invokeArgs = invokeQueue[i],provider = providerInjector.get(invokeArgs[0]);provider[invokeArgs[1]].apply(provider, invokeArgs[2]);}} else if (isFunction(module)) {runBlocks.push(providerInjector.invoke(module));} else if (isArray(module)) {runBlocks.push(providerInjector.invoke(module));} else {assertArgFn(module, 'module');}} catch (e) {if (isArray(module)) {module = module[module.length - 1];}if (e.message && e.stack && e.stack.indexOf(e.message) == -1) {// Safari & FF's stack traces don't contain error.message content// unlike those of Chrome and IE// So if stack doesn't contain message, we create a new string that contains both.// Since error.stack is read-only in Safari, I'm overriding e and not e.stack here./* jshint -W022 */e = e.message + '\n' + e.stack;}throw $injectorMinErr('modulerr', "Failed to instantiate module {0} due to:\n{1}",module, e.stack || e.message || e);}});return runBlocks;}function createInternalInjector(cache, factory) {    //创建一个内部的注入器实例对象function getService(serviceName) {if (cache.hasOwnProperty(serviceName)) {if (cache[serviceName] === INSTANTIATING) {throw $injectorMinErr('cdep', 'Circular dependency found: {0}', path.join(' <- '));}return cache[serviceName];} else {try {path.unshift(serviceName);cache[serviceName] = INSTANTIATING;return cache[serviceName] = factory(serviceName);} catch (err) {if (cache[serviceName] === INSTANTIATING) {delete cache[serviceName];}throw err;} finally {path.shift();}}}function invoke(fn, self, locals){var args = [],$inject = annotate(fn),length, i,key;for(i = 0, length = $inject.length; i < length; i++) {key = $inject[i];if (typeof key !== 'string') {throw $injectorMinErr('itkn','Incorrect injection token! Expected service name as string, got {0}', key);}args.push(locals && locals.hasOwnProperty(key)? locals[key]: getService(key));}if (!fn.$inject) {// this means that we must be an array.fn = fn[length];}// http://jsperf.com/angularjs-invoke-apply-vs-switch// #5388return fn.apply(self, args);}function instantiate(Type, locals) {var Constructor = function() {},instance, returnedValue;// Check if Type is annotated and use just the given function at n-1 as parameter// e.g. someModule.factory('greeter', ['$window', function(renamed$window) {}]);Constructor.prototype = (isArray(Type) ? Type[Type.length - 1] : Type).prototype;instance = new Constructor();returnedValue = invoke(Type, instance, locals);return isObject(returnedValue) || isFunction(returnedValue) ? returnedValue : instance;}return {invoke: invoke,instantiate: instantiate,get: getService,annotate: annotate,has: function(name) {return providerCache.hasOwnProperty(name + providerSuffix) || cache.hasOwnProperty(name);}};}}

 $provide.provider({          //在ng模块中，定义一系列的服务提供者
                    $animate: $AnimateProvider,                $controller: $ControllerProvider,$filter: $FilterProvider,$http: $HttpProvider,$location: $LocationProvider,$parse: $ParseProvider,$rootScope: $RootScopeProvider,$window: $WindowProvider});

var invokeArgs = invokeQueue[i],provider = providerInjector.get(invokeArgs[0]);provider[invokeArgs[1]].apply(provider, invokeArgs[2]);

function(servicename) {var provider = providerInjector.get(servicename + providerSuffix);return instanceInjector.invoke(provider.$get, provider);
}

function invoke(fn, self, locals){var args = [],$inject = annotate(fn),length, i,key;for(i = 0, length = $inject.length; i < length; i++) {key = $inject[i];if (typeof key !== 'string') {throw $injectorMinErr('itkn','Incorrect injection token! Expected service name as string, got {0}', key);}args.push(locals && locals.hasOwnProperty(key)? locals[key]: getService(key));}if (!fn.$inject) {// this means that we must be an array.fn = fn[length];}// http://jsperf.com/angularjs-invoke-apply-vs-switch// #5388return fn.apply(self, args);
}

injector.invoke(['$rootScope', '$rootElement', '$compile', '$injector', '$animate',function(scope, element, compile, injector, animate) {scope.$apply(function() {element.data('$injector', injector);compile(element)(scope);});}]);
return injector;

 jqLite(document).ready(function() {angularInit(document, bootstrap);}