implement opassign, fix bugs in pre/postfix, introduce a let* helper

lib/runtime/dart/async.js

 var async;
 (function(exports) {
   'use strict';
   // Function _invokeErrorHandler: (Function, Object, StackTrace) → dynamic
   function _invokeErrorHandler(errorHandler, error, stackTrace) {
     if (dart.is(errorHandler, ZoneBinaryCallback)) {
       return dart.dinvokef(errorHandler, error, stackTrace);
     } else {
       return dart.dinvokef(errorHandler, error);
     }
@@ skipping 25 matching lines @@
       if (stackTrace != null)
         return stackTrace;
       if (dart.is(error, core.Error)) {
         return dart.as(dart.dload(error, 'stackTrace'), core.StackTrace);
       }
       return null;
     }
     toString() {
       let result = `Uncaught Error: ${this.error}`;
       if (this.stackTrace != null) {
-        result = `\nStack Trace:\n${this.stackTrace}`;
+        result = core.String['+'](result, `\nStack Trace:\n${this.stackTrace}`);
       }
       return result;
     }
   }
   let _controller = Symbol('_controller');
   let _createSubscription = Symbol('_createSubscription');
   let _subscribe = Symbol('_subscribe');
   let _onListen = Symbol('_onListen');
   let _add = Symbol('_add');
   let _closeUnchecked = Symbol('_closeUnchecked');
@@ skipping 26 matching lines @@
           computation = null;
         if (computation == null)
           computation = dart.as((i) => null, dart.throw_("Unimplemented type (int) → T"));
         let timer = null;
         let computationCount = 0;
         let controller = null;
         let watch = new core.Stopwatch();
         // Function sendEvent: () → void
         function sendEvent() {
           watch.reset();
-          let data = computation(((x) => computationCount = dart.notNull(x) + 1, x)(computationCount));
+          let data = computation(((x) => (x = computationCount, computationCount = dart.notNull(x) + 1, x))());
           controller.add(data);
         }
         // Function startPeriodicTimer: () → void
         function startPeriodicTimer() {
           dart.assert(timer == null);
           timer = new Timer.periodic(period, (timer) => {
             sendEvent();
           });
         }
         controller = new (StreamController$(T))({
@@ skipping 578 matching lines @@
         if (dart.notNull(!(typeof index == 'number')) || dart.notNull(index) < 0)
           throw new core.ArgumentError(index);
         let future = new (_Future$(T))();
         let subscription = null;
         let elementIndex = 0;
         subscription = this.listen((value) => {
           if (index == elementIndex) {
             _cancelAndValue(subscription, future, value);
             return;
           }
-          elementIndex = 1;
+          elementIndex = dart.notNull(elementIndex) + 1;
         }, {
           onError: future[_completeError],
           onDone: (() => {
             future[_completeError](new core.RangeError.index(index, this, "index", null, elementIndex));
           }).bind(this),
           cancelOnError: true
         });
         return future;
       }
       timeout(timeLimit, opts) {
@@ skipping 193 matching lines @@
         this.onData(onData);
         this.onError(onError);
         this.onDone(onDone);
       }
       [_setPendingEvents](pendingEvents) {
         dart.assert(this[_pending] == null);
         if (pendingEvents == null)
           return;
         this[_pending] = pendingEvents;
         if (!dart.notNull(pendingEvents.isEmpty)) {
-          this[_state] = _BufferingStreamSubscription[_STATE_HAS_PENDING];
+          this[_state] = dart.notNull(this[_state]) | dart.notNull(_BufferingStreamSubscription[_STATE_HAS_PENDING]);
           this[_pending].schedule(this);
         }
       }
       [_extractPending]() {
         dart.assert(this[_isCanceled]);
         let events = this[_pending];
         this[_pending] = null;
         return events;
       }
       onData(handleData) {
@@ skipping 29 matching lines @@
       resume() {
         if (this[_isCanceled])
           return;
         if (this[_isPaused]) {
           this[_decrementPauseCount]();
           if (!dart.notNull(this[_isPaused])) {
             if (dart.notNull(this[_hasPending]) && !dart.notNull(this[_pending].isEmpty)) {
               this[_pending].schedule(this);
             } else {
               dart.assert(this[_mayResumeInput]);
-              this[_state] = ~dart.notNull(_BufferingStreamSubscription[_STATE_INPUT_PAUSED]);
+              this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_BufferingStreamSubscription[_STATE_INPUT_PAUSED]);
               if (!dart.notNull(this[_inCallback]))
                 this[_guardCallback](this[_onResume]);
             }
           }
         }
       }
       cancel() {
-        this[_state] = ~dart.notNull(_BufferingStreamSubscription[_STATE_WAIT_FOR_CANCEL]);
+        this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_BufferingStreamSubscription[_STATE_WAIT_FOR_CANCEL]);
         if (this[_isCanceled])
           return this[_cancelFuture];
         this[_cancel]();
         return this[_cancelFuture];
       }
       asFuture(futureValue) {
         if (futureValue === void 0)
           futureValue = null;
         let result = new (_Future$(T))();
         this[_onDone] = () => {
@@ skipping 32 matching lines @@
       get [_mayResumeInput]() {
         return !dart.notNull(this[_isPaused]) && (dart.notNull(this[_pending] == null) || dart.notNull(this[_pending].isEmpty));
       }
       get [_cancelOnError]() {
         return (dart.notNull(this[_state]) & dart.notNull(_BufferingStreamSubscription[_STATE_CANCEL_ON_ERROR])) != 0;
       }
       get isPaused() {
         return this[_isPaused];
       }
       [_cancel]() {
-        this[_state] = _BufferingStreamSubscription[_STATE_CANCELED];
+        this[_state] = dart.notNull(this[_state]) | dart.notNull(_BufferingStreamSubscription[_STATE_CANCELED]);
         if (this[_hasPending]) {
           this[_pending].cancelSchedule();
         }
         if (!dart.notNull(this[_inCallback]))
           this[_pending] = null;
         this[_cancelFuture] = this[_onCancel]();
       }
       [_incrementPauseCount]() {
         this[_state] = dart.notNull(this[_state]) + dart.notNull(_BufferingStreamSubscription[_STATE_PAUSE_COUNT]) | dart.notNull(_BufferingStreamSubscription[_STATE_INPUT_PAUSED]);
       }
       [_decrementPauseCount]() {
         dart.assert(this[_isPaused]);
-        this[_state] = _BufferingStreamSubscription[_STATE_PAUSE_COUNT];
+        this[_state] = dart.notNull(this[_state]) - dart.notNull(_BufferingStreamSubscription[_STATE_PAUSE_COUNT]);
       }
       [_add](data) {
         dart.assert(!dart.notNull(this[_isClosed]));
         if (this[_isCanceled])
           return;
         if (this[_canFire]) {
           this[_sendData](data);
         } else {
           this[_addPending](new _DelayedData(data));
         }
       }
       [_addError](error, stackTrace) {
         if (this[_isCanceled])
           return;
         if (this[_canFire]) {
           this[_sendError](error, stackTrace);
         } else {
           this[_addPending](new _DelayedError(error, stackTrace));
         }
       }
       [_close]() {
         dart.assert(!dart.notNull(this[_isClosed]));
         if (this[_isCanceled])
           return;
-        this[_state] = _BufferingStreamSubscription[_STATE_CLOSED];
+        this[_state] = dart.notNull(this[_state]) | dart.notNull(_BufferingStreamSubscription[_STATE_CLOSED]);
         if (this[_canFire]) {
           this[_sendDone]();
         } else {
           this[_addPending](new _DelayedDone());
         }
       }
       [_onPause]() {
         dart.assert(this[_isInputPaused]);
       }
       [_onResume]() {
         dart.assert(!dart.notNull(this[_isInputPaused]));
       }
       [_onCancel]() {
         dart.assert(this[_isCanceled]);
         return null;
       }
       [_addPending](event) {
         let pending = dart.as(this[_pending], _StreamImplEvents);
         if (this[_pending] == null)
           pending = this[_pending] = new _StreamImplEvents();
         pending.add(event);
         if (!dart.notNull(this[_hasPending])) {
-          this[_state] = _BufferingStreamSubscription[_STATE_HAS_PENDING];
+          this[_state] = dart.notNull(this[_state]) | dart.notNull(_BufferingStreamSubscription[_STATE_HAS_PENDING]);
           if (!dart.notNull(this[_isPaused])) {
             this[_pending].schedule(this);
           }
         }
       }
       [_sendData](data) {
         dart.assert(!dart.notNull(this[_isCanceled]));
         dart.assert(!dart.notNull(this[_isPaused]));
         dart.assert(!dart.notNull(this[_inCallback]));
         let wasInputPaused = this[_isInputPaused];
-        this[_state] = _BufferingStreamSubscription[_STATE_IN_CALLBACK];
+        this[_state] = dart.notNull(this[_state]) | dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
         this[_zone].runUnaryGuarded(this[_onData], data);
-        this[_state] = ~dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
+        this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
         this[_checkState](wasInputPaused);
       }
       [_sendError](error, stackTrace) {
         dart.assert(!dart.notNull(this[_isCanceled]));
         dart.assert(!dart.notNull(this[_isPaused]));
         dart.assert(!dart.notNull(this[_inCallback]));
         let wasInputPaused = this[_isInputPaused];
         // Function sendError: () → void
         function sendError() {
           if (dart.notNull(this[_isCanceled]) && !dart.notNull(this[_waitsForCancel]))
             return;
-          this[_state] = _BufferingStreamSubscription[_STATE_IN_CALLBACK];
+          this[_state] = dart.notNull(this[_state]) | dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
           if (dart.is(this[_onError], ZoneBinaryCallback)) {
             this[_zone].runBinaryGuarded(dart.as(this[_onError], dart.throw_("Unimplemented type (dynamic, dynamic) → dynamic")), error, stackTrace);
           } else {
             this[_zone].runUnaryGuarded(dart.as(this[_onError], dart.throw_("Unimplemented type (dynamic) → dynamic")), error);
           }
-          this[_state] = ~dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
+          this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
         }
         if (this[_cancelOnError]) {
-          this[_state] = _BufferingStreamSubscription[_STATE_WAIT_FOR_CANCEL];
+          this[_state] = dart.notNull(this[_state]) | dart.notNull(_BufferingStreamSubscription[_STATE_WAIT_FOR_CANCEL]);
           this[_cancel]();
           if (dart.is(this[_cancelFuture], Future)) {
             this[_cancelFuture].whenComplete(sendError);
           } else {
             sendError();
           }
         } else {
           sendError();
           this[_checkState](wasInputPaused);
         }
       }
       [_sendDone]() {
         dart.assert(!dart.notNull(this[_isCanceled]));
         dart.assert(!dart.notNull(this[_isPaused]));
         dart.assert(!dart.notNull(this[_inCallback]));
         // Function sendDone: () → void
         function sendDone() {
           if (!dart.notNull(this[_waitsForCancel]))
             return;
-          this[_state] = dart.notNull(_BufferingStreamSubscription[_STATE_CANCELED]) | dart.notNull(_BufferingStreamSubscription[_STATE_CLOSED]) | dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
+          this[_state] = dart.notNull(this[_state]) | dart.notNull(_BufferingStreamSubscription[_STATE_CANCELED]) | dart.notNull(_BufferingStreamSubscription[_STATE_CLOSED]) | dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
           this[_zone].runGuarded(this[_onDone]);
-          this[_state] = ~dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
+          this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
         }
         this[_cancel]();
-        this[_state] = _BufferingStreamSubscription[_STATE_WAIT_FOR_CANCEL];
+        this[_state] = dart.notNull(this[_state]) | dart.notNull(_BufferingStreamSubscription[_STATE_WAIT_FOR_CANCEL]);
         if (dart.is(this[_cancelFuture], Future)) {
           this[_cancelFuture].whenComplete(sendDone);
         } else {
           sendDone();
         }
       }
       [_guardCallback](callback) {
         dart.assert(!dart.notNull(this[_inCallback]));
         let wasInputPaused = this[_isInputPaused];
-        this[_state] = _BufferingStreamSubscription[_STATE_IN_CALLBACK];
+        this[_state] = dart.notNull(this[_state]) | dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
         dart.dinvokef(callback);
-        this[_state] = ~dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
+        this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
         this[_checkState](wasInputPaused);
       }
       [_checkState](wasInputPaused) {
         dart.assert(!dart.notNull(this[_inCallback]));
         if (dart.notNull(this[_hasPending]) && dart.notNull(this[_pending].isEmpty)) {
-          this[_state] = ~dart.notNull(_BufferingStreamSubscription[_STATE_HAS_PENDING]);
+          this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_BufferingStreamSubscription[_STATE_HAS_PENDING]);
           if (dart.notNull(this[_isInputPaused]) && dart.notNull(this[_mayResumeInput])) {
-            this[_state] = ~dart.notNull(_BufferingStreamSubscription[_STATE_INPUT_PAUSED]);
+            this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_BufferingStreamSubscription[_STATE_INPUT_PAUSED]);
           }
         }
         while (true) {
           if (this[_isCanceled]) {
             this[_pending] = null;
             return;
           }
           let isInputPaused = this[_isInputPaused];
           if (wasInputPaused == isInputPaused)
             break;
-          this[_state] = _BufferingStreamSubscription[_STATE_IN_CALLBACK];
+          this[_state] = dart.notNull(this[_state]) ^ dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
           if (isInputPaused) {
             this[_onPause]();
           } else {
             this[_onResume]();
           }
-          this[_state] = ~dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
+          this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_BufferingStreamSubscription[_STATE_IN_CALLBACK]);
           wasInputPaused = isInputPaused;
         }
         if (dart.notNull(this[_hasPending]) && !dart.notNull(this[_isPaused])) {
           this[_pending].schedule(this);
         }
       }
     }
     _BufferingStreamSubscription[dart.implements] = () => [StreamSubscription$(T), _EventSink$(T), _EventDispatch$(T)];
     _BufferingStreamSubscription._STATE_CANCEL_ON_ERROR = 1;
     _BufferingStreamSubscription._STATE_CLOSED = 2;
@@ skipping 35 matching lines @@
         super._ControllerSubscription(dart.as(controller, _StreamControllerLifecycle$(T)), onData, onError, onDone, cancelOnError);
         this[_next] = this[_previous] = this;
       }
       get [_controller]() {
         return dart.as(super[_controller], _BroadcastStreamController);
       }
       [_expectsEvent](eventId) {
         return (dart.notNull(this[_eventState]) & dart.notNull(_BroadcastSubscription[_STATE_EVENT_ID])) == eventId;
       }
       [_toggleEventId]() {
-        this[_eventState] = _BroadcastSubscription[_STATE_EVENT_ID];
+        this[_eventState] = dart.notNull(this[_eventState]) ^ dart.notNull(_BroadcastSubscription[_STATE_EVENT_ID]);
       }
       get [_isFiring]() {
         return (dart.notNull(this[_eventState]) & dart.notNull(_BroadcastSubscription[_STATE_FIRING])) != 0;
       }
       [_setRemoveAfterFiring]() {
         dart.assert(this[_isFiring]);
-        this[_eventState] = _BroadcastSubscription[_STATE_REMOVE_AFTER_FIRING];
+        this[_eventState] = dart.notNull(this[_eventState]) | dart.notNull(_BroadcastSubscription[_STATE_REMOVE_AFTER_FIRING]);
       }
       get [_removeAfterFiring]() {
         return (dart.notNull(this[_eventState]) & dart.notNull(_BroadcastSubscription[_STATE_REMOVE_AFTER_FIRING])) != 0;
       }
       [_onPause]() {}
       [_onResume]() {}
     }
     _BroadcastSubscription[dart.implements] = () => [_BroadcastSubscriptionLink];
     _BroadcastSubscription._STATE_EVENT_ID = 1;
     _BroadcastSubscription._STATE_FIRING = 2;
@@ skipping 137 matching lines @@
         }
         this[_sendError](error, stackTrace);
       }
       close() {
         if (this.isClosed) {
           dart.assert(this[_doneFuture] != null);
           return this[_doneFuture];
         }
         if (!dart.notNull(this[_mayAddEvent]))
           throw this[_addEventError]();
-        this[_state] = _BroadcastStreamController[_STATE_CLOSED];
+        this[_state] = dart.notNull(this[_state]) | dart.notNull(_BroadcastStreamController[_STATE_CLOSED]);
         let doneFuture = this[_ensureDoneFuture]();
         this[_sendDone]();
         return doneFuture;
       }
       get done() {
         return this[_ensureDoneFuture]();
       }
       addStream(stream, opts) {
         let cancelOnError = opts && 'cancelOnError' in opts ? opts.cancelOnError : true;
         if (!dart.notNull(this[_mayAddEvent]))
           throw this[_addEventError]();
-        this[_state] = _BroadcastStreamController[_STATE_ADDSTREAM];
+        this[_state] = dart.notNull(this[_state]) | dart.notNull(_BroadcastStreamController[_STATE_ADDSTREAM]);
         this[_addStreamState] = dart.as(new _AddStreamState(this, stream, cancelOnError), _AddStreamState$(T));
         return this[_addStreamState].addStreamFuture;
       }
       [_add](data) {
         this[_sendData](data);
       }
       [_addError](error, stackTrace) {
         this[_sendError](error, stackTrace);
       }
       [_close]() {
         dart.assert(this[_isAddingStream]);
         let addState = this[_addStreamState];
         this[_addStreamState] = null;
-        this[_state] = ~dart.notNull(_BroadcastStreamController[_STATE_ADDSTREAM]);
+        this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_BroadcastStreamController[_STATE_ADDSTREAM]);
         addState.complete();
       }
       [_forEachListener](action) {
         if (this[_isFiring]) {
           throw new core.StateError("Cannot fire new event. Controller is already firing an event");
         }
         if (this[_isEmpty])
           return;
         let id = dart.notNull(this[_state]) & dart.notNull(_BroadcastStreamController[_STATE_EVENT_ID]);
-        this[_state] = dart.notNull(_BroadcastStreamController[_STATE_EVENT_ID]) | dart.notNull(_BroadcastStreamController[_STATE_FIRING]);
+        this[_state] = dart.notNull(this[_state]) ^ (dart.notNull(_BroadcastStreamController[_STATE_EVENT_ID]) | dart.notNull(_BroadcastStreamController[_STATE_FIRING]));
         let link = this[_next];
         while (!dart.notNull(core.identical(link, this))) {
           let subscription = dart.as(link, _BroadcastSubscription$(T));
           if (subscription[_expectsEvent](id)) {
-            subscription[_eventState] = _BroadcastSubscription[_STATE_FIRING];
+            subscription[_eventState] = dart.notNull(subscription[_eventState]) | dart.notNull(_BroadcastSubscription[_STATE_FIRING]);
             action(subscription);
             subscription[_toggleEventId]();
             link = subscription[_next];
             if (subscription[_removeAfterFiring]) {
               this[_removeListener](subscription);
             }
-            subscription[_eventState] = ~dart.notNull(_BroadcastSubscription[_STATE_FIRING]);
+            subscription[_eventState] = dart.notNull(subscription[_eventState]) & ~dart.notNull(_BroadcastSubscription[_STATE_FIRING]);
           } else {
             link = subscription[_next];
           }
         }
-        this[_state] = ~dart.notNull(_BroadcastStreamController[_STATE_FIRING]);
+        this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_BroadcastStreamController[_STATE_FIRING]);
         if (this[_isEmpty]) {
           this[_callOnCancel]();
         }
       }
       [_callOnCancel]() {
         dart.assert(this[_isEmpty]);
         if (dart.notNull(this.isClosed) && dart.notNull(this[_doneFuture][_mayComplete])) {
           this[_doneFuture][_asyncComplete](null);
         }
         _runGuarded(this[_onCancel]);
@@ skipping 10 matching lines @@
   let _BroadcastStreamController = _BroadcastStreamController$();
   let _SyncBroadcastStreamController$ = dart.generic(function(T) {
     class _SyncBroadcastStreamController extends _BroadcastStreamController$(T) {
       _SyncBroadcastStreamController(onListen, onCancel) {
         super._BroadcastStreamController(onListen, onCancel);
       }
       [_sendData](data) {
         if (this[_isEmpty])
           return;
         if (this[_hasOneListener]) {
-          this[_state] = _BroadcastStreamController[_STATE_FIRING];
+          this[_state] = dart.notNull(this[_state]) | dart.notNull(_BroadcastStreamController[_STATE_FIRING]);
           let subscription = dart.as(this[_next], _BroadcastSubscription);
           subscription[_add](data);
-          this[_state] = ~dart.notNull(_BroadcastStreamController[_STATE_FIRING]);
+          this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_BroadcastStreamController[_STATE_FIRING]);
           if (this[_isEmpty]) {
             this[_callOnCancel]();
           }
           return;
         }
         this[_forEachListener]((subscription) => {
           subscription[_add](data);
         });
       }
       [_sendError](error, stackTrace) {
@@ skipping 87 matching lines @@
         if (!dart.notNull(this[_mayAddEvent]))
           throw this[_addEventError]();
         this[_sendError](error, stackTrace);
         while (this[_hasPending]) {
           this[_pending].handleNext(this);
         }
       }
       close() {
         if (!dart.notNull(this.isClosed) && dart.notNull(this[_isFiring])) {
           this[_addPendingEvent](new _DelayedDone());
-          this[_state] = _BroadcastStreamController[_STATE_CLOSED];
+          this[_state] = dart.notNull(this[_state]) | dart.notNull(_BroadcastStreamController[_STATE_CLOSED]);
           return super.done;
         }
         let result = super.close();
         dart.assert(!dart.notNull(this[_hasPending]));
         return result;
       }
       [_callOnCancel]() {
         if (this[_hasPending]) {
           this[_pending].clear();
           this[_pending] = null;
@@ skipping 19 matching lines @@
         if (resumeSignal === void 0)
           resumeSignal = null;
         if (resumeSignal != null)
           resumeSignal.then(this[_resume]);
         this[_pauseCount] = dart.notNull(this[_pauseCount]) + 1;
       }
       resume() {
         this[_resume](null);
       }
       [_resume](_) {
-        if (dart.notNull(this[_pauseCount]) > 0)
+        if (dart.notNull(this[_pauseCount]) > 0) {
           this[_pauseCount] = dart.notNull(this[_pauseCount]) - 1;
+        }
       }
       cancel() {
         return new _Future.immediate(null);
       }
       get isPaused() {
         return dart.notNull(this[_pauseCount]) > 0;
       }
       asFuture(value) {
         if (value === void 0)
           value = null;
@@ skipping 122 matching lines @@
               result[_completeError](theError, dart.as(theStackTrace, core.StackTrace));
             } else {
               error = theError;
               stackTrace = dart.as(theStackTrace, core.StackTrace);
             }
           } else if (remaining == 0 && !dart.notNull(eagerError)) {
             result[_completeError](error, stackTrace);
           }
         }
         for (let future of futures) {
-          let pos = ((x) => remaining = dart.notNull(x) + 1, x)(remaining);
+          let pos = remaining;
+          remaining = dart.notNull(pos) + 1;
           future.then((value) => {
             remaining = dart.notNull(remaining) - 1;
             if (values != null) {
               values[core.$set](pos, value);
               if (remaining == 0) {
                 result[_completeWithValue](values);
               }
             } else {
               if (dart.notNull(cleanUp != null) && dart.notNull(value != null)) {
                 new Future.sync(() => {
@@ skipping 1032 matching lines @@
         return new core.StateError("Cannot add event while adding a stream");
       }
       addStream(source, opts) {
         let cancelOnError = opts && 'cancelOnError' in opts ? opts.cancelOnError : true;
         if (!dart.notNull(this[_mayAddEvent]))
           throw this[_badEventState]();
         if (this[_isCanceled])
           return new _Future.immediate(null);
         let addState = new _StreamControllerAddStreamState(this, this[_varData], source, cancelOnError);
         this[_varData] = addState;
-        this[_state] = _StreamController[_STATE_ADDSTREAM];
+        this[_state] = dart.notNull(this[_state]) | dart.notNull(_StreamController[_STATE_ADDSTREAM]);
         return addState.addStreamFuture;
       }
       get done() {
         return this[_ensureDoneFuture]();
       }
       [_ensureDoneFuture]() {
         if (this[_doneFuture] == null) {
           this[_doneFuture] = this[_isCanceled] ? Future[_nullFuture] : new _Future();
         }
         return this[_doneFuture];
@@ skipping 19 matching lines @@
       close() {
         if (this.isClosed) {
           return this[_ensureDoneFuture]();
         }
         if (!dart.notNull(this[_mayAddEvent]))
           throw this[_badEventState]();
         this[_closeUnchecked]();
         return this[_ensureDoneFuture]();
       }
       [_closeUnchecked]() {
-        this[_state] = _StreamController[_STATE_CLOSED];
+        this[_state] = dart.notNull(this[_state]) | dart.notNull(_StreamController[_STATE_CLOSED]);
         if (this.hasListener) {
           this[_sendDone]();
         } else if (this[_isInitialState]) {
           this[_ensurePendingEvents]().add(new _DelayedDone());
         }
       }
       [_add](value) {
         if (this.hasListener) {
           this[_sendData](value);
         } else if (this[_isInitialState]) {
           this[_ensurePendingEvents]().add(new (_DelayedData$(T))(value));
         }
       }
       [_addError](error, stackTrace) {
         if (this.hasListener) {
           this[_sendError](error, stackTrace);
         } else if (this[_isInitialState]) {
           this[_ensurePendingEvents]().add(new _DelayedError(error, stackTrace));
         }
       }
       [_close]() {
         dart.assert(this[_isAddingStream]);
         let addState = dart.as(this[_varData], _StreamControllerAddStreamState);
         this[_varData] = addState.varData;
-        this[_state] = ~dart.notNull(_StreamController[_STATE_ADDSTREAM]);
+        this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_StreamController[_STATE_ADDSTREAM]);
         addState.complete();
       }
       [_subscribe](onData, onError, onDone, cancelOnError) {
         if (!dart.notNull(this[_isInitialState])) {
           throw new core.StateError("Stream has already been listened to.");
         }
         let subscription = new _ControllerSubscription(this, onData, onError, onDone, cancelOnError);
         let pendingEvents = this[_pendingEvents];
-        this[_state] = _StreamController[_STATE_SUBSCRIBED];
+        this[_state] = dart.notNull(this[_state]) | dart.notNull(_StreamController[_STATE_SUBSCRIBED]);
         if (this[_isAddingStream]) {
           let addState = dart.as(this[_varData], _StreamControllerAddStreamState);
           addState.varData = subscription;
           addState.resume();
         } else {
           this[_varData] = subscription;
         }
         subscription[_setPendingEvents](pendingEvents);
         subscription[_guardCallback]((() => {
           _runGuarded(this[_onListen]);
         }).bind(this));
         return dart.as(subscription, StreamSubscription$(T));
       }
       [_recordCancel](subscription) {
         let result = null;
         if (this[_isAddingStream]) {
           let addState = dart.as(this[_varData], _StreamControllerAddStreamState);
           result = addState.cancel();
         }
         this[_varData] = null;
         this[_state] = dart.notNull(this[_state]) & ~(dart.notNull(_StreamController[_STATE_SUBSCRIBED]) | dart.notNull(_StreamController[_STATE_ADDSTREAM])) | dart.notNull(_StreamController[_STATE_CANCELED]);
         if (this[_onCancel] != null) {
           if (result == null) {
             try {
               result = dart.as(this[_onCancel](), Future);
             } catch (e) {
               let s = dart.stackTrace(e);
-              result = ((_$) => {
-                _$[_asyncCompleteError](e, s);
-                return _$;
-              })(new _Future());
+              result = new _Future();
+              result[_asyncCompleteError](e, s);
             }
 
           } else {
             result = result.whenComplete(this[_onCancel]);
           }
         }
         // Function complete: () → void
         function complete() {
           if (dart.notNull(this[_doneFuture] != null) && dart.notNull(this[_doneFuture][_mayComplete])) {
             this[_doneFuture][_asyncComplete](null);
@@ skipping 214 matching lines @@
     class _GeneratedStreamImpl extends _StreamImpl$(T) {
       _GeneratedStreamImpl(pending$) {
         this[_pending] = pending$;
         this[_isUsed] = false;
         super._StreamImpl();
       }
       [_createSubscription](onData, onError, onDone, cancelOnError) {
         if (this[_isUsed])
           throw new core.StateError("Stream has already been listened to.");
         this[_isUsed] = true;
-        return ((_$) => {
-          _$[_setPendingEvents](this[_pending]());
-          return _$;
-        }).bind(this)(new _BufferingStreamSubscription(onData, onError, onDone, cancelOnError));
+        let _$ = new _BufferingStreamSubscription(onData, onError, onDone, cancelOnError);
+        _$[_setPendingEvents](this[_pending]());
+        return _$;
       }
     }
     return _GeneratedStreamImpl;
   });
   let _GeneratedStreamImpl = _GeneratedStreamImpl$();
   let _iterator = Symbol('_iterator');
   let _STATE_UNSCHEDULED = Symbol('_STATE_UNSCHEDULED');
   let _STATE_SCHEDULED = Symbol('_STATE_SCHEDULED');
   let _eventScheduled = Symbol('_eventScheduled');
   class _PendingEvents extends core.Object {
@@ skipping 203 matching lines @@
       get [_isScheduled]() {
         return (dart.notNull(this[_state]) & dart.notNull(_DoneStreamSubscription[_SCHEDULED])) != 0;
       }
       get isPaused() {
         return dart.notNull(this[_state]) >= dart.notNull(_DoneStreamSubscription[_PAUSED]);
       }
       [_schedule]() {
         if (this[_isScheduled])
           return;
         this[_zone].scheduleMicrotask(this[_sendDone]);
-        this[_state] = _DoneStreamSubscription[_SCHEDULED];
+        this[_state] = dart.notNull(this[_state]) | dart.notNull(_DoneStreamSubscription[_SCHEDULED]);
       }
       onData(handleData) {}
       onError(handleError) {}
       onDone(handleDone) {
         this[_onDone] = handleDone;
       }
       pause(resumeSignal) {
         if (resumeSignal === void 0)
           resumeSignal = null;
-        this[_state] = _DoneStreamSubscription[_PAUSED];
+        this[_state] = dart.notNull(this[_state]) + dart.notNull(_DoneStreamSubscription[_PAUSED]);
         if (resumeSignal != null)
           resumeSignal.whenComplete(this.resume);
       }
       resume() {
         if (this.isPaused) {
-          this[_state] = _DoneStreamSubscription[_PAUSED];
+          this[_state] = dart.notNull(this[_state]) - dart.notNull(_DoneStreamSubscription[_PAUSED]);
           if (!dart.notNull(this.isPaused) && !dart.notNull(this[_isSent])) {
             this[_schedule]();
           }
         }
       }
       cancel() {
         return null;
       }
       asFuture(futureValue) {
         if (futureValue === void 0)
           futureValue = null;
         let result = new _Future();
         this[_onDone] = () => {
           result[_completeWithValue](null);
         };
         return result;
       }
       [_sendDone]() {
-        this[_state] = ~dart.notNull(_DoneStreamSubscription[_SCHEDULED]);
+        this[_state] = dart.notNull(this[_state]) & ~dart.notNull(_DoneStreamSubscription[_SCHEDULED]);
         if (this.isPaused)
           return;
-        this[_state] = _DoneStreamSubscription[_DONE_SENT];
+        this[_state] = dart.notNull(this[_state]) | dart.notNull(_DoneStreamSubscription[_DONE_SENT]);
         if (this[_onDone] != null)
           this[_zone].runGuarded(this[_onDone]);
       }
     }
     _DoneStreamSubscription[dart.implements] = () => [StreamSubscription$(T)];
     _DoneStreamSubscription._DONE_SENT = 1;
     _DoneStreamSubscription._SCHEDULED = 2;
     _DoneStreamSubscription._PAUSED = 4;
     return _DoneStreamSubscription;
   });
@@ skipping 509 matching lines @@
     class _TakeStream extends _ForwardingStream$(T, T) {
       _TakeStream(source, count) {
         this[_remaining] = count;
         super._ForwardingStream(source);
         if (!(typeof count == 'number'))
           throw new core.ArgumentError(count);
       }
       [_handleData](inputEvent, sink) {
         if (dart.notNull(this[_remaining]) > 0) {
           sink[_add](inputEvent);
-          this[_remaining] = 1;
+          this[_remaining] = dart.notNull(this[_remaining]) - 1;
           if (this[_remaining] == 0) {
             sink[_close]();
           }
         }
       }
     }
     return _TakeStream;
   });
   let _TakeStream = _TakeStream$();
   let _TakeWhileStream$ = dart.generic(function(T) {
@@ skipping 1220 matching lines @@
   exports.ScheduleMicrotaskHandler = ScheduleMicrotaskHandler;
   exports.CreateTimerHandler = CreateTimerHandler;
   exports.CreatePeriodicTimerHandler = CreatePeriodicTimerHandler;
   exports.PrintHandler = PrintHandler;
   exports.ForkHandler = ForkHandler;
   exports.ZoneSpecification = ZoneSpecification;
   exports.ZoneDelegate = ZoneDelegate;
   exports.Zone = Zone;
   exports.runZoned = runZoned;
 })(async || (async = {}));