function annotate(fn) {
    var $inject, fnText, argDecl, last;
    return "function" == typeof fn ? ($inject = fn.$inject) || ($inject = [], fn.length && (fnText = fn.toString().replace(STRIP_COMMENTS, ""), argDecl = fnText.match(FN_ARGS), forEach(argDecl[1].split(FN_ARG_SPLIT), function(arg) {
        arg.replace(FN_ARG, function(all, underscore, name) {
            $inject.push(name)
        })
    })), fn.$inject = $inject) : isArray(fn) ? (last = fn.length - 1, assertArgFn(fn[last], "fn"), $inject = fn.slice(0, last)) : assertArgFn(fn, "fn", !0), $inject
}

function annotate(fn) {
  var $inject,
    fnText,
    argDecl,
    last;
  if (typeof fn == 'function') {
    if (!($inject = fn.$inject)) {
      $inject = [];
      if (fn.length) {
        fnText = fn.toString().replace(STRIP_COMMENTS, '');
        argDecl = fnText.match(FN_ARGS);
        forEach(argDecl[1].split(FN_ARG_SPLIT), function(arg){
          arg.replace(FN_ARG, function(all, underscore, name){
            $inject.push(name);
          });
        });
      }
      fn.$inject = $inject;
    }
  } else if (isArray(fn)) {
    last = fn.length - 1;
    assertArgFn(fn[last], 'fn');
    $inject = fn.slice(0, last);
  } else {
    assertArgFn(fn, 'fn', true);
  }
  return $inject;
}

arg.replace(FN_ARG, function(all, underscore, name){
    $inject.push(name);
});

var
    FN_ARG_SPLIT = /,/,
    FN_ARG = /^\s*(_?)(\S+?)\1\s*$/,
    FN_ARGS = /^function\s*[^\(]*\(\s*([^\)]*)\)/m,
    STRIP_COMMENTS = /((\/\/.*$)|(\/\*[\s\S]*?\*\/))/gm;

function annotate(fn) {
    var $inject,
        fnText,
        argDecl;
    if (typeof fn == 'function') {
        if (!($inject = fn.$inject)) {
            $inject = [];
            if (fn.length) {
                fnText = fn.toString().replace(STRIP_COMMENTS, '');
                argDecl = fnText.match(FN_ARGS);
                argDeclSplit = argDecl[1].split(FN_ARG_SPLIT);
                argDeclSplit[0].replace(FN_ARG, function(all, underscore, name) {
                    $inject.push(name);
                });
                argDeclSplit[1].replace(FN_ARG, function(all, underscore, name) {
                    $inject.push(name);
                });
                argDeclSplit[2].replace(FN_ARG, function(all, underscore, name) {
                    $inject.push(name);
                });
                console.log(fn)
                console.log(fnText);
                console.log(argDecl);
                console.log(argDeclSplit);
                console.log($inject);
            }
            fn.$inject = $inject;
        }
    }
    return $inject;
}
annotate(function(a , $scope ,$window) {});

function assertArg(arg, name, reason) {
    if (!arg) throw ngMinErr("areq", "Argument '{0}' is {1}", name || "?", reason || "required");
    return arg
}

function assertArgFn(arg, name, acceptArrayAnnotation) {
    return acceptArrayAnnotation && isArray(arg) && (arg = arg[arg.length - 1]), assertArg(isFunction(arg), name, "not a function, got " + (arg && "object" == typeof arg ? arg.constructor.name || "Object" : typeof arg)), arg
}

var fn = ["a", "$scope", "$window", function(){}];
function annotate(fn){
    last = fn.length - 1;
    assertArgFn(fn[last], 'fn');
    $inject = fn.slice(0, last);
    console.log($inject)
}
function assertArgFn(arg, name, acceptArrayAnnotation) {
    return acceptArrayAnnotation && (arg = arg[arg.length - 1]), arg
}
annotate(fn);

return {
    invoke: invoke,
    instantiate: instantiate,
    get: getService,
    annotate: annotate,
    has: function(name) {
        return providerCache.hasOwnProperty(name + providerSuffix) || cache.hasOwnProperty(name)
    }
}

function invoke(fn, self, locals) {
    var length, i, key, args = [],
        $inject = annotate(fn);
    for (i = 0, length = $inject.length; length > i; i++) {
        if (key = $inject[i], "string" != typeof key) throw $injectorMinErr("itkn", "Incorrect injection token! Expected service name as string, got {0}", key);
        args.push(locals && locals.hasOwnProperty(key) ? locals[key] : getService(key))
    }
    switch (fn.$inject || (fn = fn[length]), self ? -1 : args.length) {
        case 0:
            return fn();
        case 1:
            return fn(args[0]);
        case 2:
            return fn(args[0], args[1]);
        case 3:
            return fn(args[0], args[1], args[2]);
        case 4:
            return fn(args[0], args[1], args[2], args[3]);
        case 5:
            return fn(args[0], args[1], args[2], args[3], args[4]);
        case 6:
            return fn(args[0], args[1], args[2], args[3], args[4], args[5]);
        case 7:
            return fn(args[0], args[1], args[2], args[3], args[4], args[5], args[6]);
        case 8:
            return fn(args[0], args[1], args[2], args[3], args[4], args[5], args[6], args[7]);
        case 9:
            return fn(args[0], args[1], args[2], args[3], args[4], args[5], args[6], args[7], args[8]);
        case 10:
            return fn(args[0], args[1], args[2], args[3], args[4], args[5], args[6], args[7], args[8], args[9]);
        default:
            return fn.apply(self, args)
    }
}

for (i = 0, length = $inject.length; length > i; i++) {
    if (key = $inject[i], "string" != typeof key) throw $injectorMinErr("itkn", "Incorrect injection token! Expected service name as string, got {0}", key);
    args.push(locals && locals.hasOwnProperty(key) ? locals[key] : getService(key))
}

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;

var fn = ['wsccat','wscats',function fn(){
    console.log(arguments);
}];
    function invoke(fn, self, locals) {
var args = ['wsccat','wscats'];//annotate(fn)处理后放入args
    var fn = fn[fn.length-1];
var self = self ? -1 : fn.length-1;//switch处理
    switch (self) {
        case 0:
        return fn();
            break;
        default:
        return fn.apply(self, args);
    }
    }
//invoke(fn);
    invoke(['wsccat','wscats',function fn(){
    console.log(arguments);
}]);

function getService(serviceName) {
    if (cache.hasOwnProperty(serviceName)) {
        if (cache[serviceName] === INSTANTIATING) throw $injectorMinErr("cdep", "Circular dependency found: {0}", path.join(" <- "));
        return cache[serviceName]
    }
    try {
        return path.unshift(serviceName), cache[serviceName] = INSTANTIATING, cache[serviceName] = factory(serviceName)
    } finally {
        path.shift()
    }
}

createInternalInjector(providerCache, function() {
    throw $injectorMinErr("unpr", "Unknown provider: {0}", path.join(" <- "))
}),

providerCache = {
    $provide: {
        provider: supportObject(provider),
        factory: supportObject(factory),
        service: supportObject(service),
        value: supportObject(value),
        constant: supportObject(constant),
        decorator: decorator
    }
}

var INSTANTIATING = {}, providerSuffix = "Provider",
path = [],
loadedModules = new HashMap,
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() {
    throw $injectorMinErr("unpr", "Unknown provider: {0}", path.join(" <- "))
}),
instanceCache = {}, instanceInjector = instanceCache.$injector = createInternalInjector(instanceCache, function(servicename) {
    var provider = providerInjector.get(servicename + providerSuffix);
    return instanceInjector.invoke(provider.$get, provider)
});

providerInjector = providerCache.$injector = createInternalInjector(providerCache, function() {
    throw $injectorMinErr("unpr", "Unknown provider: {0}", path.join(" <- "))
})

providerCache = {
    $provide: {
            provider: supportObject(provider),
            factory: supportObject(factory),
            service: supportObject(service),
            value: supportObject(value),
            constant: supportObject(constant),
            decorator: decorator
          }
    },
    $injector:{
          get:getService,
          annotate:annotate,
          instantiate:instantiate,
          invoke:invoke,
          has:has
    }
}

providerInjector：{
      nvoke: invoke,
      instantiate: instantiate,
      get: getService,
      annotate: annotate,
      has: has
}

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

instanceCache：{
      $injector:{
          invoke: invoke,
          instantiate: instantiate,
          get: getService,
          annotate: annotate,
          has: has
      }
}

instanceInjector = {
      invoke: invoke,
      instantiate: instantiate,
      get: getService,
      annotate: annotate,
      has: has
}

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_;
}