'use strict'; function Route(template, defaults) { this.template = template = template + '#'; this.defaults = defaults || {}; var urlParams = this.urlParams = {}; forEach(template.split(/\W/), function(param){ if (param && template.match(new RegExp(":" + param + "\\W"))) { urlParams[param] = true; } }); } Route.prototype = { url: function(params) { var self = this, url = this.template, encodedVal; params = params || {}; forEach(this.urlParams, function(_, urlParam){ encodedVal = encodeUriSegment(params[urlParam] || self.defaults[urlParam] || ""); url = url.replace(new RegExp(":" + urlParam + "(\\W)"), encodedVal + "$1"); }); url = url.replace(/\/?#$/, ''); var query = []; forEachSorted(params, function(value, key){ if (!self.urlParams[key]) { query.push(encodeUriQuery(key) + '=' + encodeUriQuery(value)); } }); url = url.replace(/\/*$/, ''); return url + (query.length ? '?' + query.join('&') : ''); } }; function ResourceFactory(xhr) { this.xhr = xhr; } ResourceFactory.DEFAULT_ACTIONS = { 'get': {method:'GET'}, 'save': {method:'POST'}, 'query': {method:'GET', isArray:true}, 'remove': {method:'DELETE'}, 'delete': {method:'DELETE'} }; ResourceFactory.prototype = { route: function(url, paramDefaults, actions){ var self = this; var route = new Route(url); actions = extend({}, ResourceFactory.DEFAULT_ACTIONS, actions); function extractParams(data){ var ids = {}; forEach(paramDefaults || {}, function(value, key){ ids[key] = value.charAt && value.charAt(0) == '@' ? getter(data, value.substr(1)) : value; }); return ids; } function Resource(value){ copy(value || {}, this); } forEach(actions, function(action, name){ var isPostOrPut = action.method == 'POST' || action.method == 'PUT'; Resource[name] = function(a1, a2, a3, a4) { var params = {}; var data; var success = noop; var error = null; switch(arguments.length) { case 4: error = a4; success = a3; //fallthrough case 3: case 2: if (isFunction(a2)) { if (isFunction(a1)) { success = a1; error = a2; break; } success = a2; error = a3; //fallthrough } else { params = a1; data = a2; success = a3; break; } case 1: if (isFunction(a1)) success = a1; else if (isPostOrPut) data = a1; else params = a1; break; case 0: break; default: throw "Expected between 0-4 arguments [params, data, success, error], got " + arguments.length + " arguments."; } var value = this instanceof Resource ? this : (action.isArray ? [] : new Resource(data)); self.xhr( action.method, route.url(extend({}, extractParams(data), action.params || {}, params)), data, function(status, response) { if (response) { if (action.isArray) { value.length = 0; forEach(response, function(item) { value.push(new Resource(item)); }); } else { copy(response, value); } } (success||noop)(value); }, error || action.verifyCache, action.verifyCache); return value; }; Resource.bind = function(additionalParamDefaults){ return self.route(url, extend({}, paramDefaults, additionalParamDefaults), actions); }; Resource.prototype['$' + name] = function(a1, a2, a3) { var params = extractParams(this), success = noop, error; switch(arguments.length) { case 3: params = a1; success = a2; error = a3; break; case 2: case 1: if (isFunction(a1)) { success = a1; error = a2; } else { params = a1; success = a2 || noop; } case 0: break; default: throw "Expected between 1-3 arguments [params, success, error], got " + arguments.length + " arguments."; } var data = isPostOrPut ? this : undefined; Resource[name].call(this, params, data, success, error); }; }); return Resource; } }; 43' href='#n43'>43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991
'use strict';

/**
 * DESIGN NOTES
 *
 * The design decisions behind the scope are heavily favored for speed and memory consumption.
 *
 * The typical use of scope is to watch the expressions, which most of the time return the same
 * value as last time so we optimize the operation.
 *
 * Closures construction is expensive in terms of speed as well as memory:
 *   - No closures, instead use prototypical inheritance for API
 *   - Internal state needs to be stored on scope directly, which means that private state is
 *     exposed as $$____ properties
 *
 * Loop operations are optimized by using while(count--) { ... }
 *   - this means that in order to keep the same order of execution as addition we have to add
 *     items to the array at the beginning (shift) instead of at the end (push)
 *
 * Child scopes are created and removed often
 *   - Using an array would be slow since inserts in middle are expensive so we use linked list
 *
 * There are few watches then a lot of observers. This is why you don't want the observer to be
 * implemented in the same way as watch. Watch requires return of initialization function which
 * are expensive to construct.
 */


/**
 * @ngdoc object
 * @name ng.$rootScopeProvider
 * @description
 *
 * Provider for the $rootScope service.
 */

/**
 * @ngdoc function
 * @name ng.$rootScopeProvider#digestTtl
 * @methodOf ng.$rootScopeProvider
 * @description
 *
 * Sets the number of `$digest` iterations the scope should attempt to execute before giving up and assuming that the model is unstable.
 *
 * The current default is 10 iterations.
 *
 * In complex applications it's possible that the dependencies between `$watch`s will result in several digest iterations.
 * However if an application needs more than the default 10 digest iterations for its model to stabilize then you should investigate what is causing the model to continuously change during the digest.
 *
 * Increasing the TTL could have performance implications, so you should not change it without proper justification.
 *
 * @param {number} limit The number of digest iterations.
 */


/**
 * @ngdoc object
 * @name ng.$rootScope
 * @description
 *
 * Every application has a single root {@link ng.$rootScope.Scope scope}.
 * All other scopes are descendant scopes of the root scope. Scopes provide separation
 * between the model and the view, via a mechanism for watching the model for changes.
 * They also provide an event emission/broadcast and subscription facility. See the
 * {@link guide/scope developer guide on scopes}.
 */
function $RootScopeProvider(){
  var TTL = 10;
  var $rootScopeMinErr = minErr('$rootScope');

  this.digestTtl = function(value) {
    if (arguments.length) {
      TTL = value;
    }
    return TTL;
  };

  this.$get = ['$injector', '$exceptionHandler', '$parse', '$browser',
      function( $injector,   $exceptionHandler,   $parse,   $browser) {

    /**
     * @ngdoc function
     * @name ng.$rootScope.Scope
     *
     * @description
     * A root scope can be retrieved using the {@link ng.$rootScope $rootScope} key from the
     * {@link AUTO.$injector $injector}. Child scopes are created using the
     * {@link ng.$rootScope.Scope#methods_$new $new()} method. (Most scopes are created automatically when
     * compiled HTML template is executed.)
     *
     * Here is a simple scope snippet to show how you can interact with the scope.
     * <pre>
     * <file src="./test/ng/rootScopeSpec.js" tag="docs1" />
     * </pre>
     *
     * # Inheritance
     * A scope can inherit from a parent scope, as in this example:
     * <pre>
         var parent = $rootScope;
         var child = parent.$new();

         parent.salutation = "Hello";
         child.name = "World";
         expect(child.salutation).toEqual('Hello');

         child.salutation = "Welcome";
         expect(child.salutation).toEqual('Welcome');
         expect(parent.salutation).toEqual('Hello');
     * </pre>
     *
     *
     * @param {Object.<string, function()>=} providers Map of service factory which need to be provided
     *     for the current scope. Defaults to {@link ng}.
     * @param {Object.<string, *>=} instanceCache Provides pre-instantiated services which should
     *     append/override services provided by `providers`. This is handy when unit-testing and having
     *     the need to override a default service.
     * @returns {Object} Newly created scope.
     *
     */
    function Scope() {
      this.$id = nextUid();
      this.$$phase = this.$parent = this.$$watchers =
                     this.$$nextSibling = this.$$prevSibling =
                     this.$$childHead = this.$$childTail = null;
      this['this'] = this.$root =  this;
      this.$$destroyed = false;
      this.$$asyncQueue = [];
      this.$$postDigestQueue = [];
      this.$$listeners = {};
      this.$$isolateBindings = {};
    }

    /**
     * @ngdoc property
     * @name ng.$rootScope.Scope#$id
     * @propertyOf ng.$rootScope.Scope
     * @returns {number} Unique scope ID (monotonically increasing alphanumeric sequence) useful for
     *   debugging.
     */


    Scope.prototype = {
      constructor: Scope,
      /**
       * @ngdoc function
       * @name ng.$rootScope.Scope#$new
       * @methodOf ng.$rootScope.Scope
       * @function
       *
       * @description
       * Creates a new child {@link ng.$rootScope.Scope scope}.
       *
       * The parent scope will propagate the {@link ng.$rootScope.Scope#$digest $digest()} and
       * {@link ng.$rootScope.Scope#$digest $digest()} events. The scope can be removed from the scope
       * hierarchy using {@link ng.$rootScope.Scope#$destroy $destroy()}.
       *
       * {@link ng.$rootScope.Scope#$destroy $destroy()} must be called on a scope when it is desired for
       * the scope and its child scopes to be permanently detached from the parent and thus stop
       * participating in model change detection and listener notification by invoking.
       *
       * @param {boolean} isolate If true, then the scope does not prototypically inherit from the
       *         parent scope. The scope is isolated, as it can not see parent scope properties.
       *         When creating widgets, it is useful for the widget to not accidentally read parent
       *         state.
       *
       * @returns {Object} The newly created child scope.
       *
       */
      $new: function(isolate) {
        var Child,
            child;

        if (isolate) {
          child = new Scope();
          child.$root = this.$root;
          // ensure that there is just one async queue per $rootScope and its children
          child.$$asyncQueue = this.$$asyncQueue;
          child.$$postDigestQueue = this.$$postDigestQueue;
        } else {
          Child = function() {}; // should be anonymous; This is so that when the minifier munges
            // the name it does not become random set of chars. This will then show up as class
            // name in the debugger.
          Child.prototype = this;
          child = new Child();
          child.$id = nextUid();
        }
        child['this'] = child;
        child.$$listeners = {};
        child.$parent = this;
        child.$$watchers = child.$$nextSibling = child.$$childHead = child.$$childTail = null;
        child.$$prevSibling = this.$$childTail;
        if (this.$$childHead) {
          this.$$childTail.$$nextSibling = child;
          this.$$childTail = child;
        } else {
          this.$$childHead = this.$$childTail = child;
        }
        return child;
      },

      /**
       * @ngdoc function
       * @name ng.$rootScope.Scope#$watch
       * @methodOf ng.$rootScope.Scope
       * @function
       *
       * @description
       * Registers a `listener` callback to be executed whenever the `watchExpression` changes.
       *
       * - The `watchExpression` is called on every call to {@link ng.$rootScope.Scope#$digest $digest()} and
       *   should return the value that will be watched. (Since {@link ng.$rootScope.Scope#$digest $digest()}
       *   reruns when it detects changes the `watchExpression` can execute multiple times per
       *   {@link ng.$rootScope.Scope#$digest $digest()} and should be idempotent.)
       * - The `listener` is called only when the value from the current `watchExpression` and the
       *   previous call to `watchExpression` are not equal (with the exception of the initial run,
       *   see below). The inequality is determined according to
       *   {@link angular.equals} function. To save the value of the object for later comparison, the
       *   {@link angular.copy} function is used. It also means that watching complex options will
       *   have adverse memory and performance implications.
       * - The watch `listener` may change the model, which may trigger other `listener`s to fire. This
       *   is achieved by rerunning the watchers until no changes are detected. The rerun iteration
       *   limit is 10 to prevent an infinite loop deadlock.
       *
       *
       * If you want to be notified whenever {@link ng.$rootScope.Scope#$digest $digest} is called,
       * you can register a `watchExpression` function with no `listener`. (Since `watchExpression`
       * can execute multiple times per {@link ng.$rootScope.Scope#$digest $digest} cycle when a change is
       * detected, be prepared for multiple calls to your listener.)
       *
       * After a watcher is registered with the scope, the `listener` fn is called asynchronously
       * (via {@link ng.$rootScope.Scope#$evalAsync $evalAsync}) to initialize the
       * watcher. In rare cases, this is undesirable because the listener is called when the result
       * of `watchExpression` didn't change. To detect this scenario within the `listener` fn, you
       * can compare the `newVal` and `oldVal`. If these two values are identical (`===`) then the
       * listener was called due to initialization.
       *
       *
       * # Example
       * <pre>
           // let's assume that scope was dependency injected as the $rootScope
           var scope = $rootScope;
           scope.name = 'misko';
           scope.counter = 0;

           expect(scope.counter).toEqual(0);
           scope.$watch('name', function(newValue, oldValue) { scope.counter = scope.counter + 1; });
           expect(scope.counter).toEqual(0);

           scope.$digest();
           // no variable change
           expect(scope.counter).toEqual(0);

           scope.name = 'adam';
           scope.$digest();
           expect(scope.counter).toEqual(1);
       * </pre>
       *
       *
       *
       * @param {(function()|string)} watchExpression Expression that is evaluated on each
       *    {@link ng.$rootScope.Scope#$digest $digest} cycle. A change in the return value triggers a
       *    call to the `listener`.
       *
       *    - `string`: Evaluated as {@link guide/expression expression}
       *    - `function(scope)`: called with current `scope` as a parameter.
       * @param {(function()|string)=} listener Callback called whenever the return value of
       *   the `watchExpression` changes.
       *
       *    - `string`: Evaluated as {@link guide/expression expression}
       *    - `function(newValue, oldValue, scope)`: called with current and previous values as parameters.
       *
       * @param {boolean=} objectEquality Compare object for equality rather than for reference.
       * @returns {function()} Returns a deregistration function for this listener.
       */
      $watch: function(watchExp, listener, objectEquality) {
        var scope = this,
            get = compileToFn(watchExp, 'watch'),
            array = scope.$$watchers,
            watcher = {
              fn: listener,
              last: initWatchVal,
              get: get,
              exp: watchExp,
              eq: !!objectEquality
            };

        // in the case user pass string, we need to compile it, do we really need this ?
        if (!isFunction(listener)) {
          var listenFn = compileToFn(listener || noop, 'listener');
          watcher.fn = function(newVal, oldVal, scope) {listenFn(scope);};
        }

        if (typeof watchExp == 'string' && get.constant) {
          var originalFn = watcher.fn;
          watcher.fn = function(newVal, oldVal, scope) {
            originalFn.call(this, newVal, oldVal, scope);
            arrayRemove(array, watcher);
          };
        }

        if (!array) {
          array = scope.$$watchers = [];
        }
        // we use unshift since we use a while loop in $digest for speed.
        // the while loop reads in reverse order.
        array.unshift(watcher);

        return function() {
          arrayRemove(array, watcher);
        };
      },


      /**
       * @ngdoc function
       * @name ng.$rootScope.Scope#$watchCollection
       * @methodOf ng.$rootScope.Scope
       * @function
       *
       * @description
       * Shallow watches the properties of an object and fires whenever any of the properties change
       * (for arrays, this implies watching the array items; for object maps, this implies watching the properties).
       * If a change is detected, the `listener` callback is fired.
       *
       * - The `obj` collection is observed via standard $watch operation and is examined on every call to $digest() to
       *   see if any items have been added, removed, or moved.
       * - The `listener` is called whenever anything within the `obj` has changed. Examples include adding, removing,
       *   and moving items belonging to an object or array.
       *
       *
       * # Example
       * <pre>
          $scope.names = ['igor', 'matias', 'misko', 'james'];
          $scope.dataCount = 4;

          $scope.$watchCollection('names', function(newNames, oldNames) {
            $scope.dataCount = newNames.length;
          });

          expect($scope.dataCount).toEqual(4);
          $scope.$digest();

          //still at 4 ... no changes
          expect($scope.dataCount).toEqual(4);

          $scope.names.pop();
          $scope.$digest();

          //now there's been a change
          expect($scope.dataCount).toEqual(3);
       * </pre>
       *
       *
       * @param {string|Function(scope)} obj Evaluated as {@link guide/expression expression}. The expression value
       *    should evaluate to an object or an array which is observed on each
       *    {@link ng.$rootScope.Scope#$digest $digest} cycle. Any shallow change within the collection will trigger
       *    a call to the `listener`.
       *
       * @param {function(newCollection, oldCollection, scope)} listener a callback function that is fired with both
       *    the `newCollection` and `oldCollection` as parameters.
       *    The `newCollection` object is the newly modified data obtained from the `obj` expression and the
       *    `oldCollection` object is a copy of the former collection data.
       *    The `scope` refers to the current scope.
       *
       * @returns {function()} Returns a de-registration function for this listener. When the de-registration function
       * is executed, the internal watch operation is terminated.
       */
      $watchCollection: function(obj, listener) {
        var self = this;
        var oldValue;
        var newValue;
        var changeDetected = 0;
        var objGetter = $parse(obj);
        var internalArray = [];
        var internalObject = {};
        var oldLength = 0;

        function $watchCollectionWatch() {
          newValue = objGetter(self);
          var newLength, key;

          if (!isObject(newValue)) {
            if (oldValue !== newValue) {
              oldValue = newValue;
              changeDetected++;
            }
          } else if (isArrayLike(newValue)) {
            if (oldValue !== internalArray) {
              // we are transitioning from something which was not an array into array.
              oldValue = internalArray;
              oldLength = oldValue.length = 0;
              changeDetected++;
            }

            newLength = newValue.length;

            if (oldLength !== newLength) {
              // if lengths do not match we need to trigger change notification
              changeDetected++;
              oldValue.length = oldLength = newLength;
            }
            // copy the items to oldValue and look for changes.
            for (var i = 0; i < newLength; i++) {
              if (oldValue[i] !== newValue[i]) {
                changeDetected++;
                oldValue[i] = newValue[i];
              }
            }
          } else {
            if (oldValue !== internalObject) {
              // we are transitioning from something which was not an object into object.
              oldValue = internalObject = {};
              oldLength = 0;
              changeDetected++;
            }
            // copy the items to oldValue and look for changes.
            newLength = 0;
            for (key in newValue) {
              if (newValue.hasOwnProperty(key)) {
                newLength++;
                if (oldValue.hasOwnProperty(key)) {
                  if (oldValue[key] !== newValue[key]) {
                    changeDetected++;
                    oldValue[key] = newValue[key];
                  }
                } else {
                  oldLength++;
                  oldValue[key] = newValue[key];
                  changeDetected++;
                }
              }
            }
            if (oldLength > newLength) {
              // we used to have more keys, need to find them and destroy them.
              changeDetected++;
              for(key in oldValue) {
                if (oldValue.hasOwnProperty(key) && !newValue.hasOwnProperty(key)) {
                  oldLength--;
                  delete oldValue[key];
                }
              }
            }
          }
          return changeDetected;
        }

        function $watchCollectionAction() {
          listener(newValue, oldValue, self);
        }

        return this.$watch($watchCollectionWatch, $watchCollectionAction);
      },

      /**
       * @ngdoc function
       * @name ng.$rootScope.Scope#$digest
       * @methodOf ng.$rootScope.Scope
       * @function
       *
       * @description
       * Processes all of the {@link ng.$rootScope.Scope#$watch watchers} of the current scope and its children.
       * Because a {@link ng.$rootScope.Scope#$watch watcher}'s listener can change the model, the
       * `$digest()` keeps calling the {@link ng.$rootScope.Scope#$watch watchers} until no more listeners are
       * firing. This means that it is possible to get into an infinite loop. This function will throw
       * `'Maximum iteration limit exceeded.'` if the number of iterations exceeds 10.
       *
       * Usually, you don't call `$digest()` directly in
       * {@link ng.directive:ngController controllers} or in
       * {@link ng.$compileProvider#methods_directive directives}.
       * Instead, you should call {@link ng.$rootScope.Scope#$apply $apply()} (typically from within a
       * {@link ng.$compileProvider#methods_directive directives}), which will force a `$digest()`.
       *
       * If you want to be notified whenever `$digest()` is called,
       * you can register a `watchExpression` function with {@link ng.$rootScope.Scope#$watch $watch()}
       * with no `listener`.
       *
       * In unit tests, you may need to call `$digest()` to simulate the scope life cycle.
       *
       * # Example
       * <pre>
           var scope = ...;
           scope.name = 'misko';
           scope.counter = 0;

           expect(scope.counter).toEqual(0);
           scope.$watch('name', function(newValue, oldValue) {
             scope.counter = scope.counter + 1;
           });
           expect(scope.counter).toEqual(0);

           scope.$digest();
           // no variable change
           expect(scope.counter).toEqual(0);

           scope.name = 'adam';
           scope.$digest();
           expect(scope.counter).toEqual(1);
       * </pre>
       *
       */
      $digest: function() {
        var watch, value, last,
            watchers,
            asyncQueue = this.$$asyncQueue,
            postDigestQueue = this.$$postDigestQueue,
            length,
            dirty, ttl = TTL,
            next, current, target = this,
            watchLog = [],
            logIdx, logMsg, asyncTask;

        beginPhase('$digest');

        do { // "while dirty" loop
          dirty = false;
          current = target;

          while(asyncQueue.length) {
            try {
              asyncTask = asyncQueue.shift();
              asyncTask.scope.$eval(asyncTask.expression);
            } catch (e) {
              $exceptionHandler(e);
            }
          }

          do { // "traverse the scopes" loop
            if ((watchers = current.$$watchers)) {
              // process our watches
              length = watchers.length;
              while (length--) {
                try {
                  watch = watchers[length];
                  // Most common watches are on primitives, in which case we can short
                  // circuit it with === operator, only when === fails do we use .equals
                  if (watch && (value = watch.get(current)) !== (last = watch.last) &&
                      !(watch.eq
                          ? equals(value, last)
                          : (typeof value == 'number' && typeof last == 'number'
                             && isNaN(value) && isNaN(last)))) {
                    dirty = true;
                    watch.last = watch.eq ? copy(value) : value;
                    watch.fn(value, ((last === initWatchVal) ? value : last), current);
                    if (ttl < 5) {
                      logIdx = 4 - ttl;
                      if (!watchLog[logIdx]) watchLog[logIdx] = [];
                      logMsg = (isFunction(watch.exp))
                          ? 'fn: ' + (watch.exp.name || watch.exp.toString())
                          : watch.exp;
                      logMsg += '; newVal: ' + toJson(value) + '; oldVal: ' + toJson(last);
                      watchLog[logIdx].push(logMsg);
                    }
                  }
                } catch (e) {
                  $exceptionHandler(e);
                }
              }
            }

            // Insanity Warning: scope depth-first traversal
            // yes, this code is a bit crazy, but it works and we have tests to prove it!
            // this piece should be kept in sync with the traversal in $broadcast
            if (!(next = (current.$$childHead || (current !== target && current.$$nextSibling)))) {
              while(current !== target && !(next = current.$$nextSibling)) {
                current = current.$parent;
              }
            }
          } while ((current = next));

          if(dirty && !(ttl--)) {
            clearPhase();
            throw $rootScopeMinErr('infdig',
                '{0} $digest() iterations reached. Aborting!\nWatchers fired in the last 5 iterations: {1}',
                TTL, toJson(watchLog));
          }
        } while (dirty || asyncQueue.length);

        clearPhase();

        while(postDigestQueue.length) {
          try {
            postDigestQueue.shift()();
          } catch (e) {
            $exceptionHandler(e);
          }
        }
      },


      /**
       * @ngdoc event
       * @name ng.$rootScope.Scope#$destroy
       * @eventOf ng.$rootScope.Scope
       * @eventType broadcast on scope being destroyed
       *
       * @description
       * Broadcasted when a scope and its children are being destroyed.
       *
       * Note that, in AngularJS, there is also a `$destroy` jQuery event, which can be used to
       * clean up DOM bindings before an element is removed from the DOM.
       */

      /**
       * @ngdoc function
       * @name ng.$rootScope.Scope#$destroy
       * @methodOf ng.$rootScope.Scope
       * @function
       *
       * @description
       * Removes the current scope (and all of its children) from the parent scope. Removal implies
       * that calls to {@link ng.$rootScope.Scope#$digest $digest()} will no longer
       * propagate to the current scope and its children. Removal also implies that the current
       * scope is eligible for garbage collection.
       *
       * The `$destroy()` is usually used by directives such as
       * {@link ng.directive:ngRepeat ngRepeat} for managing the
       * unrolling of the loop.
       *
       * Just before a scope is destroyed, a `$destroy` event is broadcasted on this scope.
       * Application code can register a `$destroy` event handler that will give it a chance to
       * perform any necessary cleanup.
       *
       * Note that, in AngularJS, there is also a `$destroy` jQuery event, which can be used to
       * clean up DOM bindings before an element is removed from the DOM.
       */
      $destroy: function() {
        // we can't destroy the root scope or a scope that has been already destroyed
        if ($rootScope == this || this.$$destroyed) return;
        var parent = this.$parent;

        this.$broadcast('$destroy');
        this.$$destroyed = true;

        if (parent.$$childHead == this) parent.$$childHead = this.$$nextSibling;
        if (parent.$$childTail == this) parent.$$childTail = this.$$prevSibling;
        if (this.$$prevSibling) this.$$prevSibling.$$nextSibling = this.$$nextSibling;
        if (this.$$nextSibling) this.$$nextSibling.$$prevSibling = this.$$prevSibling;

        // This is bogus code that works around Chrome's GC leak
        // see: https://github.com/angular/angular.js/issues/1313#issuecomment-10378451
        this.$parent = this.$$nextSibling = this.$$prevSibling = this.$$childHead =
            this.$$childTail = null;
      },

      /**
       * @ngdoc function
       * @name ng.$rootScope.Scope#$eval
       * @methodOf ng.$rootScope.Scope
       * @function
       *
       * @description
       * Executes the `expression` on the current scope and returns the result. Any exceptions in the
       * expression are propagated (uncaught). This is useful when evaluating Angular expressions.
       *
       * # Example
       * <pre>
           var scope = ng.$rootScope.Scope();
           scope.a = 1;
           scope.b = 2;

           expect(scope.$eval('a+b')).toEqual(3);
           expect(scope.$eval(function(scope){ return scope.a + scope.b; })).toEqual(3);
       * </pre>
       *
       * @param {(string|function())=} expression An angular expression to be executed.
       *
       *    - `string`: execute using the rules as defined in  {@link guide/expression expression}.
       *    - `function(scope)`: execute the function with the current `scope` parameter.
       *
       * @returns {*} The result of evaluating the expression.
       */
      $eval: function(expr, locals) {
        return $parse(expr)(this, locals);
      },

      /**
       * @ngdoc function
       * @name ng.$rootScope.Scope#$evalAsync
       * @methodOf ng.$rootScope.Scope
       * @function
       *
       * @description
       * Executes the expression on the current scope at a later point in time.
       *
       * The `$evalAsync` makes no guarantees as to when the `expression` will be executed, only that:
       *
       *   - it will execute after the function that scheduled the evaluation (preferably before DOM rendering).
       *   - at least one {@link ng.$rootScope.Scope#$digest $digest cycle} will be performed after `expression` execution.
       *
       * Any exceptions from the execution of the expression are forwarded to the
       * {@link ng.$exceptionHandler $exceptionHandler} service.
       *
       * __Note:__ if this function is called outside of a `$digest` cycle, a new `$digest` cycle will be scheduled.
       * However, it is encouraged to always call code that changes the model from within an `$apply` call.
       * That includes code evaluated via `$evalAsync`.
       *
       * @param {(string|function())=} expression An angular expression to be executed.
       *
       *    - `string`: execute using the rules as defined in {@link guide/expression expression}.
       *    - `function(scope)`: execute the function with the current `scope` parameter.
       *
       */
      $evalAsync: function(expr) {
        // if we are outside of an $digest loop and this is the first time we are scheduling async task also schedule
        // async auto-flush
        if (!$rootScope.$$phase && !$rootScope.$$asyncQueue.length) {
          $browser.defer(function() {
            if ($rootScope.$$asyncQueue.length) {
              $rootScope.$digest();
            }
          });
        }

        this.$$asyncQueue.push({scope: this, expression: expr});
      },

      $$postDigest : function(fn) {
        this.$$postDigestQueue.push(fn);
      },

      /**
       * @ngdoc function
       * @name ng.$rootScope.Scope#$apply
       * @methodOf ng.$rootScope.Scope
       * @function
       *
       * @description
       * `$apply()` is used to execute an expression in angular from outside of the angular framework.
       * (For example from browser DOM events, setTimeout, XHR or third party libraries).
       * Because we are calling into the angular framework we need to perform proper scope life cycle
       * of {@link ng.$exceptionHandler exception handling},
       * {@link ng.$rootScope.Scope#$digest executing watches}.
       *
       * ## Life cycle
       *
       * # Pseudo-Code of `$apply()`
       * <pre>
           function $apply(expr) {
             try {
               return $eval(expr);
             } catch (e) {
               $exceptionHandler(e);
             } finally {
               $root.$digest();
             }
           }
       * </pre>
       *
       *
       * Scope's `$apply()` method transitions through the following stages:
       *
       * 1. The {@link guide/expression expression} is executed using the
       *    {@link ng.$rootScope.Scope#$eval $eval()} method.
       * 2. Any exceptions from the execution of the expression are forwarded to the
       *    {@link ng.$exceptionHandler $exceptionHandler} service.
       * 3. The {@link ng.$rootScope.Scope#$watch watch} listeners are fired immediately after the expression
       *    was executed using the {@link ng.$rootScope.Scope#$digest $digest()} method.
       *
       *
       * @param {(string|function())=} exp An angular expression to be executed.
       *
       *    - `string`: execute using the rules as defined in {@link guide/expression expression}.
       *    - `function(scope)`: execute the function with current `scope` parameter.
       *
       * @returns {*} The result of evaluating the expression.
       */
      $apply: function(expr) {
        try {
          beginPhase('$apply');
          return this.$eval(expr);
        } catch (e) {
          $exceptionHandler(e);
        } finally {
          clearPhase();
          try {
            $rootScope.$digest();
          } catch (e) {
            $exceptionHandler(e);
            throw e;
          }
        }
      },

      /**
       * @ngdoc function
       * @name ng.$rootScope.Scope#$on
       * @methodOf ng.$rootScope.Scope
       * @function
       *
       * @description
       * Listens on events of a given type. See {@link ng.$rootScope.Scope#$emit $emit} for discussion of
       * event life cycle.
       *
       * The event listener function format is: `function(event, args...)`. The `event` object
       * passed into the listener has the following attributes:
       *
       *   - `targetScope` - `{Scope}`: the scope on which the event was `$emit`-ed or `$broadcast`-ed.
       *   - `currentScope` - `{Scope}`: the current scope which is handling the event.
       *   - `name` - `{string}`: name of the event.
       *   - `stopPropagation` - `{function=}`: calling `stopPropagation` function will cancel further event
       *     propagation (available only for events that were `$emit`-ed).
       *   - `preventDefault` - `{function}`: calling `preventDefault` sets `defaultPrevented` flag to true.
       *   - `defaultPrevented` - `{boolean}`: true if `preventDefault` was called.
       *
       * @param {string} name Event name to listen on.
       * @param {function(event, args...)} listener Function to call when the event is emitted.
       * @returns {function()} Returns a deregistration function for this listener.
       */
      $on: function(name, listener) {
        var namedListeners = this.$$listeners[name];
        if (!namedListeners) {
          this.$$listeners[name] = namedListeners = [];
        }
        namedListeners.push(listener);

        return function() {
          namedListeners[indexOf(namedListeners, listener)] = null;
        };
      },


      /**
       * @ngdoc function
       * @name ng.$rootScope.Scope#$emit
       * @methodOf ng.$rootScope.Scope
       * @function
       *
       * @description
       * Dispatches an event `name` upwards through the scope hierarchy notifying the
       * registered {@link ng.$rootScope.Scope#$on} listeners.
       *
       * The event life cycle starts at the scope on which `$emit` was called. All
       * {@link ng.$rootScope.Scope#$on listeners} listening for `name` event on this scope get notified.
       * Afterwards, the event traverses upwards toward the root scope and calls all registered
       * listeners along the way. The event will stop propagating if one of the listeners cancels it.
       *
       * Any exception emitted from the {@link ng.$rootScope.Scope#$on listeners} will be passed
       * onto the {@link ng.$exceptionHandler $exceptionHandler} service.
       *
       * @param {string} name Event name to emit.
       * @param {...*} args Optional set of arguments which will be passed onto the event listeners.
       * @return {Object} Event object (see {@link ng.$rootScope.Scope#$on}).
       */
      $emit: function(name, args) {
        var empty = [],
            namedListeners,
            scope = this,
            stopPropagation = false,
            event = {
              name: name,
              targetScope: scope,
              stopPropagation: function() {stopPropagation = true;},
              preventDefault: function() {
                event.defaultPrevented = true;
              },
              defaultPrevented: false
            },
            listenerArgs = concat([event], arguments, 1),
            i, length;

        do {
          namedListeners = scope.$$listeners[name] || empty;
          event.currentScope = scope;
          for (i=0, length=namedListeners.length; i<length; i++) {

            // if listeners were deregistered, defragment the array
            if (!namedListeners[i]) {
              namedListeners.splice(i, 1);
              i--;
              length--;
              continue;
            }
            try {
              //allow all listeners attached to the current scope to run
              namedListeners[i].apply(null, listenerArgs);
            } catch (e) {
              $exceptionHandler(e);
            }
          }
          //if any listener on the current scope stops propagation, prevent bubbling
          if (stopPropagation) return event;
          //traverse upwards
          scope = scope.$parent;
        } while (scope);

        return event;
      },


      /**
       * @ngdoc function
       * @name ng.$rootScope.Scope#$broadcast
       * @methodOf ng.$rootScope.Scope
       * @function
       *
       * @description
       * Dispatches an event `name` downwards to all child scopes (and their children) notifying the
       * registered {@link ng.$rootScope.Scope#$on} listeners.
       *
       * The event life cycle starts at the scope on which `$broadcast` was called. All
       * {@link ng.$rootScope.Scope#$on listeners} listening for `name` event on this scope get notified.
       * Afterwards, the event propagates to all direct and indirect scopes of the current scope and
       * calls all registered listeners along the way. The event cannot be canceled.
       *
       * Any exception emitted from the {@link ng.$rootScope.Scope#$on listeners} will be passed
       * onto the {@link ng.$exceptionHandler $exceptionHandler} service.
       *
       * @param {string} name Event name to broadcast.
       * @param {...*} args Optional set of arguments which will be passed onto the event listeners.
       * @return {Object} Event object, see {@link ng.$rootScope.Scope#$on}
       */
      $broadcast: function(name, args) {
        var target = this,
            current = target,
            next = target,
            event = {
              name: name,
              targetScope: target,
              preventDefault: function() {
                event.defaultPrevented = true;
              },
              defaultPrevented: false
            },
            listenerArgs = concat([event], arguments, 1),
            listeners, i, length;

        //down while you can, then up and next sibling or up and next sibling until back at root
        do {
          current = next;
          event.currentScope = current;
          listeners = current.$$listeners[name] || [];
          for (i=0, length = listeners.length; i<length; i++) {
            // if listeners were deregistered, defragment the array
            if (!listeners[i]) {
              listeners.splice(i, 1);
              i--;
              length--;
              continue;
            }

            try {
              listeners[i].apply(null, listenerArgs);
            } catch(e) {
              $exceptionHandler(e);
            }
          }

          // Insanity Warning: scope depth-first traversal
          // yes, this code is a bit crazy, but it works and we have tests to prove it!
          // this piece should be kept in sync with the traversal in $digest
          if (!(next = (current.$$childHead || (current !== target && current.$$nextSibling)))) {
            while(current !== target && !(next = current.$$nextSibling)) {
              current = current.$parent;
            }
          }
        } while ((current = next));

        return event;
      }
    };

    var $rootScope = new Scope();

    return $rootScope;


    function beginPhase(phase) {
      if ($rootScope.$$phase) {
        throw $rootScopeMinErr('inprog', '{0} already in progress', $rootScope.$$phase);
      }

      $rootScope.$$phase = phase;
    }

    function clearPhase() {
      $rootScope.$$phase = null;
    }

    function compileToFn(exp, name) {
      var fn = $parse(exp);
      assertArgFn(fn, name);
      return fn;
    }

    /**
     * function used as an initial value for watchers.
     * because it's unique we can easily tell it apart from other values
     */
    function initWatchVal() {}
  }];
}