fixes browser/runtime_test, and a few extension member fixes

lib/runtime/dart/_interceptors.js

 var _interceptors = dart.defineLibrary(_interceptors, {});
 var core = dart.import(core);
 var _internal = dart.import(_internal);
 var _js_helper = dart.lazyImport(_js_helper);
 var collection = dart.import(collection);
 var math = dart.import(math);
 (function(exports, core, _internal, _js_helper, collection, math) {
   'use strict';
   let JSArray$ = dart.generic(function(E) {
+    dart.defineExtensionNames([
+      'checkGrowable',
+      'add',
+      'removeAt',
+      'insert',
+      'insertAll',
+      'setAll',
+      'removeLast',
+      'remove',
+      'removeWhere',
+      'retainWhere',
+      'where',
+      'expand',
+      'addAll',
+      'clear',
+      'forEach',
+      'map',
+      'join',
+      'take',
+      'takeWhile',
+      'skip',
+      'skipWhile',
+      'reduce',
+      'fold',
+      'firstWhere',
+      'lastWhere',
+      'singleWhere',
+      'elementAt',
+      'sublist',
+      'getRange',
+      'first',
+      'last',
+      'single',
+      'removeRange',
+      'setRange',
+      'fillRange',
+      'replaceRange',
+      'any',
+      'every',
+      'reversed',
+      'sort',
+      'shuffle',
+      'indexOf',
+      'lastIndexOf',
+      'contains',
+      'isEmpty',
+      'isNotEmpty',
+      'toString',
+      'toList',
+      'toSet',
+      'iterator',
+      'hashCode',
+      'length',
+      'length',
+      'get',
+      'set',
+      'asMap'
+    ]);
     class JSArray extends core.Object {
       JSArray() {
       }
       static typed(allocation) {
         return dart.list(allocation, E);
       }
       static markFixed(allocation) {
         return JSArray$(E).typed(JSArray$().markFixedList(dart.as(allocation, core.List)));
       }
       static markGrowable(allocation) {
         return JSArray$().typed(allocation);
       }
       static markFixedList(list) {
         list.fixed$length = Array;
         return list;
       }
-      checkGrowable(reason) {
+      [dartx.checkGrowable](reason) {
         if (this.fixed$length) {
           throw new core.UnsupportedError(dart.as(reason, core.String));
         }
       }
-      add(value) {
+      [dartx.add](value) {
         dart.as(value, E);
         this[dartx.checkGrowable]('add');
         this.push(value);
       }
-      removeAt(index) {
+      [dartx.removeAt](index) {
         if (!(typeof index == 'number'))
           throw new core.ArgumentError(index);
         if (dart.notNull(index) < 0 || dart.notNull(index) >= dart.notNull(this.length)) {
           throw new core.RangeError.value(index);
         }
         this[dartx.checkGrowable]('removeAt');
         return this.splice(index, 1)[0];
       }
-      insert(index, value) {
+      [dartx.insert](index, value) {
         dart.as(value, E);
         if (!(typeof index == 'number'))
           throw new core.ArgumentError(index);
         if (dart.notNull(index) < 0 || dart.notNull(index) > dart.notNull(this.length)) {
           throw new core.RangeError.value(index);
         }
         this[dartx.checkGrowable]('insert');
         this.splice(index, 0, value);
       }
-      insertAll(index, iterable) {
+      [dartx.insertAll](index, iterable) {
         dart.as(iterable, core.Iterable$(E));
         this[dartx.checkGrowable]('insertAll');
         _internal.IterableMixinWorkaround.insertAllList(this, index, iterable);
       }
-      setAll(index, iterable) {
+      [dartx.setAll](index, iterable) {
         dart.as(iterable, core.Iterable$(E));
         _internal.IterableMixinWorkaround.setAllList(this, index, iterable);
       }
-      removeLast() {
+      [dartx.removeLast]() {
         this[dartx.checkGrowable]('removeLast');
         if (this.length == 0)
           throw new core.RangeError.value(-1);
         return dart.as(this.pop(), E);
       }
-      remove(element) {
+      [dartx.remove](element) {
         this[dartx.checkGrowable]('remove');
         for (let i = 0; dart.notNull(i) < dart.notNull(this.length); i = dart.notNull(i) + 1) {
           if (dart.equals(this[dartx.get](i), element)) {
             this.splice(i, 1);
             return true;
           }
         }
         return false;
       }
-      removeWhere(test) {
+      [dartx.removeWhere](test) {
         dart.as(test, dart.functionType(core.bool, [E]));
         _internal.IterableMixinWorkaround.removeWhereList(this, test);
       }
-      retainWhere(test) {
+      [dartx.retainWhere](test) {
         dart.as(test, dart.functionType(core.bool, [E]));
         _internal.IterableMixinWorkaround.removeWhereList(this, dart.fn(element => !dart.notNull(test(element)), core.bool, [E]));
       }
-      where(f) {
+      [dartx.where](f) {
         dart.as(f, dart.functionType(core.bool, [E]));
         return new (_internal.IterableMixinWorkaround$(E))().where(this, f);
       }
-      expand(f) {
+      [dartx.expand](f) {
         dart.as(f, dart.functionType(core.Iterable, [E]));
         return _internal.IterableMixinWorkaround.expand(this, f);
       }
-      addAll(collection) {
+      [dartx.addAll](collection) {
         dart.as(collection, core.Iterable$(E));
         for (let e of collection) {
           this[dartx.add](e);
         }
       }
-      clear() {
+      [dartx.clear]() {
         this.length = 0;
       }
-      forEach(f) {
+      [dartx.forEach](f) {
         dart.as(f, dart.functionType(dart.void, [E]));
         let length = this.length;
         for (let i = 0; dart.notNull(i) < dart.notNull(length); i = dart.notNull(i) + 1) {
           f(dart.as(this[i], E));
           if (length != this.length) {
             throw new core.ConcurrentModificationError(this);
           }
         }
       }
-      map(f) {
+      [dartx.map](f) {
         dart.as(f, dart.functionType(core.Object, [E]));
         return _internal.IterableMixinWorkaround.mapList(this, f);
       }
-      join(separator) {
+      [dartx.join](separator) {
         if (separator === void 0)
           separator = "";
         let list = core.List.new(this.length);
         for (let i = 0; dart.notNull(i) < dart.notNull(this.length); i = dart.notNull(i) + 1) {
           list[dartx.set](i, `${this[dartx.get](i)}`);
         }
         return list.join(separator);
       }
-      take(n) {
+      [dartx.take](n) {
         return new (_internal.IterableMixinWorkaround$(E))().takeList(this, n);
       }
-      takeWhile(test) {
+      [dartx.takeWhile](test) {
         dart.as(test, dart.functionType(core.bool, [E]));
         return new (_internal.IterableMixinWorkaround$(E))().takeWhile(this, test);
       }
-      skip(n) {
+      [dartx.skip](n) {
         return new (_internal.IterableMixinWorkaround$(E))().skipList(this, n);
       }
-      skipWhile(test) {
+      [dartx.skipWhile](test) {
         dart.as(test, dart.functionType(core.bool, [E]));
         return new (_internal.IterableMixinWorkaround$(E))().skipWhile(this, test);
       }
-      reduce(combine) {
+      [dartx.reduce](combine) {
         dart.as(combine, dart.functionType(E, [E, E]));
         return dart.as(_internal.IterableMixinWorkaround.reduce(this, combine), E);
       }
-      fold(initialValue, combine) {
+      [dartx.fold](initialValue, combine) {
         dart.as(combine, dart.functionType(core.Object, [dart.bottom, E]));
         return _internal.IterableMixinWorkaround.fold(this, initialValue, combine);
       }
-      firstWhere(test, opts) {
+      [dartx.firstWhere](test, opts) {
         dart.as(test, dart.functionType(core.bool, [E]));
         let orElse = opts && 'orElse' in opts ? opts.orElse : null;
         dart.as(orElse, dart.functionType(E, []));
         return dart.as(_internal.IterableMixinWorkaround.firstWhere(this, test, orElse), E);
       }
-      lastWhere(test, opts) {
+      [dartx.lastWhere](test, opts) {
         dart.as(test, dart.functionType(core.bool, [E]));
         let orElse = opts && 'orElse' in opts ? opts.orElse : null;
         dart.as(orElse, dart.functionType(E, []));
         return dart.as(_internal.IterableMixinWorkaround.lastWhereList(this, test, orElse), E);
       }
-      singleWhere(test) {
+      [dartx.singleWhere](test) {
         dart.as(test, dart.functionType(core.bool, [E]));
         return dart.as(_internal.IterableMixinWorkaround.singleWhere(this, test), E);
       }
-      elementAt(index) {
+      [dartx.elementAt](index) {
         return this[dartx.get](index);
       }
-      sublist(start, end) {
+      [dartx.sublist](start, end) {
         if (end === void 0)
           end = null;
         _js_helper.checkNull(start);
         if (!(typeof start == 'number'))
           throw new core.ArgumentError(start);
         if (dart.notNull(start) < 0 || dart.notNull(start) > dart.notNull(this.length)) {
           throw new core.RangeError.range(start, 0, this.length);
         }
         if (end == null) {
           end = this.length;
         } else {
           if (!(typeof end == 'number'))
             throw new core.ArgumentError(end);
           if (dart.notNull(end) < dart.notNull(start) || dart.notNull(end) > dart.notNull(this.length)) {
             throw new core.RangeError.range(end, start, this.length);
           }
         }
         if (start == end)
           return dart.list([], E);
         return JSArray$(E).typed(this.slice(start, end));
       }
-      getRange(start, end) {
+      [dartx.getRange](start, end) {
         return new (_internal.IterableMixinWorkaround$(E))().getRangeList(this, start, end);
       }
-      get first() {
+      get [dartx.first]() {
         if (dart.notNull(this.length) > 0)
           return this[dartx.get](0);
         throw new core.StateError("No elements");
       }
-      get last() {
+      get [dartx.last]() {
         if (dart.notNull(this.length) > 0)
           return this[dartx.get](dart.notNull(this.length) - 1);
         throw new core.StateError("No elements");
       }
-      get single() {
+      get [dartx.single]() {
         if (this.length == 1)
           return this[dartx.get](0);
         if (this.length == 0)
           throw new core.StateError("No elements");
         throw new core.StateError("More than one element");
       }
-      removeRange(start, end) {
+      [dartx.removeRange](start, end) {
         this[dartx.checkGrowable]('removeRange');
         let receiverLength = this.length;
         if (dart.notNull(start) < 0 || dart.notNull(start) > dart.notNull(receiverLength)) {
           throw new core.RangeError.range(start, 0, receiverLength);
         }
         if (dart.notNull(end) < dart.notNull(start) || dart.notNull(end) > dart.notNull(receiverLength)) {
           throw new core.RangeError.range(end, start, receiverLength);
         }
         _internal.Lists.copy(this, end, this, start, dart.notNull(receiverLength) - dart.notNull(end));
         this.length = dart.notNull(receiverLength) - (dart.notNull(end) - dart.notNull(start));
       }
-      setRange(start, end, iterable, skipCount) {
+      [dartx.setRange](start, end, iterable, skipCount) {
         dart.as(iterable, core.Iterable$(E));
         if (skipCount === void 0)
           skipCount = 0;
         _internal.IterableMixinWorkaround.setRangeList(this, start, end, iterable, skipCount);
       }
-      fillRange(start, end, fillValue) {
+      [dartx.fillRange](start, end, fillValue) {
         if (fillValue === void 0)
           fillValue = null;
         dart.as(fillValue, E);
         _internal.IterableMixinWorkaround.fillRangeList(this, start, end, fillValue);
       }
-      replaceRange(start, end, iterable) {
+      [dartx.replaceRange](start, end, iterable) {
         dart.as(iterable, core.Iterable$(E));
         _internal.IterableMixinWorkaround.replaceRangeList(this, start, end, iterable);
       }
-      any(f) {
+      [dartx.any](f) {
         dart.as(f, dart.functionType(core.bool, [E]));
         return _internal.IterableMixinWorkaround.any(this, f);
       }
-      every(f) {
+      [dartx.every](f) {
         dart.as(f, dart.functionType(core.bool, [E]));
         return _internal.IterableMixinWorkaround.every(this, f);
       }
-      get reversed() {
+      get [dartx.reversed]() {
         return new (_internal.IterableMixinWorkaround$(E))().reversedList(this);
       }
-      sort(compare) {
+      [dartx.sort](compare) {
         if (compare === void 0)
           compare = null;
         dart.as(compare, dart.functionType(core.int, [E, E]));
         _internal.IterableMixinWorkaround.sortList(this, compare);
       }
-      shuffle(random) {
+      [dartx.shuffle](random) {
         if (random === void 0)
           random = null;
         _internal.IterableMixinWorkaround.shuffleList(this, random);
       }
-      indexOf(element, start) {
+      [dartx.indexOf](element, start) {
         if (start === void 0)
           start = 0;
         return _internal.IterableMixinWorkaround.indexOfList(this, element, start);
       }
-      lastIndexOf(element, start) {
+      [dartx.lastIndexOf](element, start) {
         if (start === void 0)
           start = null;
         return _internal.IterableMixinWorkaround.lastIndexOfList(this, element, start);
       }
-      contains(other) {
+      [dartx.contains](other) {
         for (let i = 0; dart.notNull(i) < dart.notNull(this.length); i = dart.notNull(i) + 1) {
           if (dart.equals(this[dartx.get](i), other))
             return true;
         }
         return false;
       }
-      get isEmpty() {
+      get [dartx.isEmpty]() {
         return this.length == 0;
       }
-      get isNotEmpty() {
+      get [dartx.isNotEmpty]() {
         return !dart.notNull(this[dartx.isEmpty]);
       }
-      toString() {
+      [dartx.toString]() {
         return collection.ListBase.listToString(this);
       }
-      toList(opts) {
+      [dartx.toList](opts) {
         let growable = opts && 'growable' in opts ? opts.growable : true;
         let list = this.slice();
         if (!dart.notNull(growable))
           JSArray$().markFixedList(dart.as(list, core.List));
         return JSArray$(E).typed(list);
       }
-      toSet() {
+      [dartx.toSet]() {
         return core.Set$(E).from(this);
       }
-      get iterator() {
+      get [dartx.iterator]() {
         return new (_internal.ListIterator$(E))(this);
       }
-      get hashCode() {
+      get [dartx.hashCode]() {
         return _js_helper.Primitives.objectHashCode(this);
       }
       get length() {
         return dart.as(this.length, core.int);
       }
       set length(newLength) {
         if (!(typeof newLength == 'number'))
           throw new core.ArgumentError(newLength);
         if (dart.notNull(newLength) < 0)
           throw new core.RangeError.value(newLength);
         this[dartx.checkGrowable]('set length');
         this.length = newLength;
       }
-      get(index) {
+      [dartx.get](index) {
         if (!(typeof index == 'number'))
           throw new core.ArgumentError(index);
         if (dart.notNull(index) >= dart.notNull(this.length) || dart.notNull(index) < 0)
           throw new core.RangeError.value(index);
         return dart.as(this[index], E);
       }
-      set(index, value) {
+      [dartx.set](index, value) {
         dart.as(value, E);
         if (!(typeof index == 'number'))
           throw new core.ArgumentError(index);
         if (dart.notNull(index) >= dart.notNull(this.length) || dart.notNull(index) < 0)
           throw new core.RangeError.value(index);
         this[index] = value;
       }
-      asMap() {
+      [dartx.asMap]() {
         return new (_internal.IterableMixinWorkaround$(E))().asMapList(this);
       }
     }
     dart.setBaseClass(JSArray, dart.global.Array);
     JSArray[dart.implements] = () => [core.List$(E), JSIndexable];
     dart.setSignature(JSArray, {
       constructors: () => ({
         JSArray: [JSArray$(E), []],
         typed: [JSArray$(E), [core.Object]],
         markFixed: [JSArray$(E), [core.Object]],
         markGrowable: [JSArray$(E), [core.Object]]
       }),
       methods: () => ({
-        checkGrowable: [core.Object, [core.Object]],
-        add: [dart.void, [E]],
-        removeAt: [E, [core.int]],
-        insert: [dart.void, [core.int, E]],
-        insertAll: [dart.void, [core.int, core.Iterable$(E)]],
-        setAll: [dart.void, [core.int, core.Iterable$(E)]],
-        removeLast: [E, []],
-        remove: [core.bool, [core.Object]],
-        removeWhere: [dart.void, [dart.functionType(core.bool, [E])]],
-        retainWhere: [dart.void, [dart.functionType(core.bool, [E])]],
-        where: [core.Iterable$(E), [dart.functionType(core.bool, [E])]],
-        expand: [core.Iterable, [dart.functionType(core.Iterable, [E])]],
-        addAll: [dart.void, [core.Iterable$(E)]],
-        clear: [dart.void, []],
-        forEach: [dart.void, [dart.functionType(dart.void, [E])]],
-        map: [core.Iterable, [dart.functionType(core.Object, [E])]],
-        join: [core.String, [], [core.String]],
-        take: [core.Iterable$(E), [core.int]],
-        takeWhile: [core.Iterable$(E), [dart.functionType(core.bool, [E])]],
-        skip: [core.Iterable$(E), [core.int]],
-        skipWhile: [core.Iterable$(E), [dart.functionType(core.bool, [E])]],
-        reduce: [E, [dart.functionType(E, [E, E])]],
-        fold: [core.Object, [core.Object, dart.functionType(core.Object, [dart.bottom, E])]],
-        firstWhere: [E, [dart.functionType(core.bool, [E])], {orElse: dart.functionType(E, [])}],
-        lastWhere: [E, [dart.functionType(core.bool, [E])], {orElse: dart.functionType(E, [])}],
-        singleWhere: [E, [dart.functionType(core.bool, [E])]],
-        elementAt: [E, [core.int]],
-        sublist: [core.List$(E), [core.int], [core.int]],
-        getRange: [core.Iterable$(E), [core.int, core.int]],
-        removeRange: [dart.void, [core.int, core.int]],
-        setRange: [dart.void, [core.int, core.int, core.Iterable$(E)], [core.int]],
-        fillRange: [dart.void, [core.int, core.int], [E]],
-        replaceRange: [dart.void, [core.int, core.int, core.Iterable$(E)]],
-        any: [core.bool, [dart.functionType(core.bool, [E])]],
-        every: [core.bool, [dart.functionType(core.bool, [E])]],
-        sort: [dart.void, [], [dart.functionType(core.int, [E, E])]],
-        shuffle: [dart.void, [], [math.Random]],
-        indexOf: [core.int, [core.Object], [core.int]],
-        lastIndexOf: [core.int, [core.Object], [core.int]],
-        contains: [core.bool, [core.Object]],
-        toList: [core.List$(E), [], {growable: core.bool}],
-        toSet: [core.Set$(E), []],
-        get: [E, [core.int]],
-        set: [dart.void, [core.int, E]],
-        asMap: [core.Map$(core.int, E), []]
+        [dartx.checkGrowable]: [core.Object, [core.Object]],
+        [dartx.add]: [dart.void, [E]],
+        [dartx.removeAt]: [E, [core.int]],
+        [dartx.insert]: [dart.void, [core.int, E]],
+        [dartx.insertAll]: [dart.void, [core.int, core.Iterable$(E)]],
+        [dartx.setAll]: [dart.void, [core.int, core.Iterable$(E)]],
+        [dartx.removeLast]: [E, []],
+        [dartx.remove]: [core.bool, [core.Object]],
+        [dartx.removeWhere]: [dart.void, [dart.functionType(core.bool, [E])]],
+        [dartx.retainWhere]: [dart.void, [dart.functionType(core.bool, [E])]],
+        [dartx.where]: [core.Iterable$(E), [dart.functionType(core.bool, [E])]],
+        [dartx.expand]: [core.Iterable, [dart.functionType(core.Iterable, [E])]],
+        [dartx.addAll]: [dart.void, [core.Iterable$(E)]],
+        [dartx.clear]: [dart.void, []],
+        [dartx.forEach]: [dart.void, [dart.functionType(dart.void, [E])]],
+        [dartx.map]: [core.Iterable, [dart.functionType(core.Object, [E])]],
+        [dartx.join]: [core.String, [], [core.String]],
+        [dartx.take]: [core.Iterable$(E), [core.int]],
+        [dartx.takeWhile]: [core.Iterable$(E), [dart.functionType(core.bool, [E])]],
+        [dartx.skip]: [core.Iterable$(E), [core.int]],
+        [dartx.skipWhile]: [core.Iterable$(E), [dart.functionType(core.bool, [E])]],
+        [dartx.reduce]: [E, [dart.functionType(E, [E, E])]],
+        [dartx.fold]: [core.Object, [core.Object, dart.functionType(core.Object, [dart.bottom, E])]],
+        [dartx.firstWhere]: [E, [dart.functionType(core.bool, [E])], {orElse: dart.functionType(E, [])}],
+        [dartx.lastWhere]: [E, [dart.functionType(core.bool, [E])], {orElse: dart.functionType(E, [])}],
+        [dartx.singleWhere]: [E, [dart.functionType(core.bool, [E])]],
+        [dartx.elementAt]: [E, [core.int]],
+        [dartx.sublist]: [core.List$(E), [core.int], [core.int]],
+        [dartx.getRange]: [core.Iterable$(E), [core.int, core.int]],
+        [dartx.removeRange]: [dart.void, [core.int, core.int]],
+        [dartx.setRange]: [dart.void, [core.int, core.int, core.Iterable$(E)], [core.int]],
+        [dartx.fillRange]: [dart.void, [core.int, core.int], [E]],
+        [dartx.replaceRange]: [dart.void, [core.int, core.int, core.Iterable$(E)]],
+        [dartx.any]: [core.bool, [dart.functionType(core.bool, [E])]],
+        [dartx.every]: [core.bool, [dart.functionType(core.bool, [E])]],
+        [dartx.sort]: [dart.void, [], [dart.functionType(core.int, [E, E])]],
+        [dartx.shuffle]: [dart.void, [], [math.Random]],
+        [dartx.indexOf]: [core.int, [core.Object], [core.int]],
+        [dartx.lastIndexOf]: [core.int, [core.Object], [core.int]],
+        [dartx.contains]: [core.bool, [core.Object]],
+        [dartx.toList]: [core.List$(E), [], {growable: core.bool}],
+        [dartx.toSet]: [core.Set$(E), []],
+        [dartx.get]: [E, [core.int]],
+        [dartx.set]: [dart.void, [core.int, E]],
+        [dartx.asMap]: [core.Map$(core.int, E), []]
       }),
       statics: () => ({markFixedList: [core.List, [core.List]]}),
       names: ['markFixedList']
     });
     return JSArray;
   });
   let JSArray = JSArray$();
   dart.registerExtension(dart.global.Array, JSArray);
   let JSMutableArray$ = dart.generic(function(E) {
     class JSMutableArray extends JSArray$(E) {
@@ skipping 26 matching lines @@
   let _tdivFast = Symbol('_tdivFast');
   let _tdivSlow = Symbol('_tdivSlow');
   let _shlPositive = Symbol('_shlPositive');
   let _shrReceiverPositive = Symbol('_shrReceiverPositive');
   let _shrOtherPositive = Symbol('_shrOtherPositive');
   let _shrBothPositive = Symbol('_shrBothPositive');
   class JSNumber extends Interceptor {
     JSNumber() {
       super.Interceptor();
     }
-    compareTo(b) {
+    [dartx.compareTo](b) {
       if (!dart.is(b, core.num))
         throw new core.ArgumentError(b);
       if (dart.notNull(this[dartx['<']](b))) {
         return -1;
       } else if (dart.notNull(this[dartx['>']](b))) {
         return 1;
       } else if (dart.equals(this, b)) {
         if (dart.equals(this, 0)) {
           let bIsNegative = b[dartx.isNegative];
           if (this[dartx.isNegative] == bIsNegative)
             return 0;
           if (dart.notNull(this[dartx.isNegative]))
             return -1;
           return 1;
         }
         return 0;
       } else if (dart.notNull(this[dartx.isNaN])) {
         if (dart.notNull(b[dartx.isNaN])) {
           return 0;
         }
         return 1;
       } else {
         return -1;
       }
     }
-    get isNegative() {
+    get [dartx.isNegative]() {
       return dart.equals(this, 0) ? (1)[dartx['/']](this) < 0 : this[dartx['<']](0);
     }
-    get isNaN() {
+    get [dartx.isNaN]() {
       return isNaN(this);
     }
-    get isInfinite() {
+    get [dartx.isInfinite]() {
       return this == Infinity || this == -Infinity;
     }
-    get isFinite() {
+    get [dartx.isFinite]() {
       return isFinite(this);
     }
-    remainder(b) {
+    [dartx.remainder](b) {
       _js_helper.checkNull(b);
       if (!dart.is(b, core.num))
         throw new core.ArgumentError(b);
       return this % b;
     }
-    abs() {
+    [dartx.abs]() {
       return Math.abs(this);
     }
-    get sign() {
+    get [dartx.sign]() {
       return dart.notNull(this[dartx['>']](0)) ? 1 : dart.notNull(this[dartx['<']](0)) ? -1 : this;
     }
-    toInt() {
+    [dartx.toInt]() {
       if (dart.notNull(this[dartx['>=']](JSNumber._MIN_INT32)) && dart.notNull(this[dartx['<=']](JSNumber._MAX_INT32))) {
         return this | 0;
       }
       if (isFinite(this)) {
         return this[dartx.truncateToDouble]() + 0;
       }
       throw new core.UnsupportedError('' + this);
     }
-    truncate() {
+    [dartx.truncate]() {
       return this[dartx.toInt]();
     }
-    ceil() {
+    [dartx.ceil]() {
       return this[dartx.ceilToDouble]()[dartx.toInt]();
     }
-    floor() {
+    [dartx.floor]() {
       return this[dartx.floorToDouble]()[dartx.toInt]();
     }
-    round() {
+    [dartx.round]() {
       return this[dartx.roundToDouble]()[dartx.toInt]();
     }
-    ceilToDouble() {
+    [dartx.ceilToDouble]() {
       return Math.ceil(this);
     }
-    floorToDouble() {
+    [dartx.floorToDouble]() {
       return Math.floor(this);
     }
-    roundToDouble() {
+    [dartx.roundToDouble]() {
       if (dart.notNull(this[dartx['<']](0))) {
         return -Math.round(-this);
       } else {
         return Math.round(this);
       }
     }
-    truncateToDouble() {
+    [dartx.truncateToDouble]() {
       return dart.notNull(this[dartx['<']](0)) ? this[dartx.ceilToDouble]() : this[dartx.floorToDouble]();
     }
-    clamp(lowerLimit, upperLimit) {
+    [dartx.clamp](lowerLimit, upperLimit) {
       if (!dart.is(lowerLimit, core.num))
         throw new core.ArgumentError(lowerLimit);
       if (!dart.is(upperLimit, core.num))
         throw new core.ArgumentError(upperLimit);
       if (dart.notNull(lowerLimit[dartx.compareTo](upperLimit)) > 0) {
         throw new core.ArgumentError(lowerLimit);
       }
       if (dart.notNull(this[dartx.compareTo](lowerLimit)) < 0)
         return lowerLimit;
       if (dart.notNull(this[dartx.compareTo](upperLimit)) > 0)
         return upperLimit;
       return this;
     }
-    toDouble() {
+    [dartx.toDouble]() {
       return this;
     }
-    toStringAsFixed(fractionDigits) {
+    [dartx.toStringAsFixed](fractionDigits) {
       _js_helper.checkInt(fractionDigits);
       if (dart.notNull(fractionDigits) < 0 || dart.notNull(fractionDigits) > 20) {
         throw new core.RangeError(fractionDigits);
       }
       let result = this.toFixed(fractionDigits);
       if (dart.equals(this, 0) && dart.notNull(this[dartx.isNegative]))
         return `-${result}`;
       return result;
     }
-    toStringAsExponential(fractionDigits) {
+    [dartx.toStringAsExponential](fractionDigits) {
       if (fractionDigits === void 0)
         fractionDigits = null;
       let result = null;
       if (fractionDigits != null) {
         _js_helper.checkInt(fractionDigits);
         if (dart.notNull(fractionDigits) < 0 || dart.notNull(fractionDigits) > 20) {
           throw new core.RangeError(fractionDigits);
         }
         result = this.toExponential(fractionDigits);
       } else {
         result = this.toExponential();
       }
       if (dart.equals(this, 0) && dart.notNull(this[dartx.isNegative]))
         return `-${result}`;
       return result;
     }
-    toStringAsPrecision(precision) {
+    [dartx.toStringAsPrecision](precision) {
       _js_helper.checkInt(precision);
       if (dart.notNull(precision) < 1 || dart.notNull(precision) > 21) {
         throw new core.RangeError(precision);
       }
       let result = this.toPrecision(precision);
       if (dart.equals(this, 0) && dart.notNull(this[dartx.isNegative]))
         return `-${result}`;
       return result;
     }
-    toRadixString(radix) {
+    [dartx.toRadixString](radix) {
       _js_helper.checkInt(radix);
       if (dart.notNull(radix) < 2 || dart.notNull(radix) > 36)
         throw new core.RangeError(radix);
       let result = this.toString(radix);
       let rightParenCode = 41;
       if (result[dartx.codeUnitAt](dart.notNull(result.length) - 1) != rightParenCode) {
         return result;
       }
       return JSNumber._handleIEtoString(result);
     }
     static _handleIEtoString(result) {
       let match = /^([\da-z]+)(?:\.([\da-z]+))?\(e\+(\d+)\)$/.exec(result);
       if (match == null) {
         throw new core.UnsupportedError(`Unexpected toString result: ${result}`);
       }
       result = dart.dindex(match, 1);
       let exponent = +dart.dindex(match, 3);
       if (dart.dindex(match, 2) != null) {
         result = result + dart.dindex(match, 2);
         exponent = dart.notNull(exponent) - dart.dindex(match, 2).length;
       }
       return dart.notNull(result) + "0"[dartx['*']](exponent);
     }
-    toString() {
+    [dartx.toString]() {
       if (dart.equals(this, 0) && 1 / this < 0) {
         return '-0.0';
       } else {
         return "" + this;
       }
     }
-    get hashCode() {
+    get [dartx.hashCode]() {
       return this & 0x1FFFFFFF;
     }
-    ['unary-']() {
+    [dartx['unary-']]() {
       return -this;
     }
-    ['+'](other) {
+    [dartx['+']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return this + other;
     }
-    ['-'](other) {
+    [dartx['-']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return this - other;
     }
-    ['/'](other) {
+    [dartx['/']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return this / other;
     }
-    ['*'](other) {
+    [dartx['*']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return this * other;
     }
-    ['%'](other) {
+    [dartx['%']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       let result = this % other;
       if (result == 0)
         return 0;
       if (dart.notNull(result) > 0)
         return result;
       if (other < 0) {
         return dart.notNull(result) - other;
       } else {
         return dart.notNull(result) + other;
       }
     }
     [_isInt32](value) {
       return (value | 0) === value;
     }
-    ['~/'](other) {
+    [dartx['~/']](other) {
       if (false)
         this[_tdivFast](other);
       if (dart.notNull(this[_isInt32](this)) && dart.notNull(this[_isInt32](other)) && 0 != other && -1 != other) {
         return this / other | 0;
       } else {
         return this[_tdivSlow](other);
       }
     }
     [_tdivFast](other) {
       return dart.notNull(this[_isInt32](this)) ? this / other | 0 : (this / other)[dartx.toInt]();
     }
     [_tdivSlow](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return (this / other)[dartx.toInt]();
     }
-    ['<<'](other) {
+    [dartx['<<']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       if (other < 0)
         throw new core.ArgumentError(other);
       return this[_shlPositive](other);
     }
     [_shlPositive](other) {
       return other > 31 ? 0 : dart.as(this << other >>> 0, core.num);
     }
-    ['>>'](other) {
+    [dartx['>>']](other) {
       if (false)
         this[_shrReceiverPositive](other);
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       if (other < 0)
         throw new core.ArgumentError(other);
       return this[_shrOtherPositive](other);
     }
     [_shrOtherPositive](other) {
       return this > 0 ? this[_shrBothPositive](other) : dart.as(this >> (dart.notNull(other) > 31 ? 31 : other) >>> 0, core.num);
     }
     [_shrReceiverPositive](other) {
       if (other < 0)
         throw new core.ArgumentError(other);
       return this[_shrBothPositive](other);
     }
     [_shrBothPositive](other) {
       return other > 31 ? 0 : dart.as(this >>> other, core.num);
     }
-    ['&'](other) {
+    [dartx['&']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return dart.as((this & other) >>> 0, core.num);
     }
-    ['|'](other) {
+    [dartx['|']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return dart.as((this | other) >>> 0, core.num);
     }
-    ['^'](other) {
+    [dartx['^']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return dart.as((this ^ other) >>> 0, core.num);
     }
-    ['<'](other) {
+    [dartx['<']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return this < other;
     }
-    ['>'](other) {
+    [dartx['>']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return this > other;
     }
-    ['<='](other) {
+    [dartx['<=']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return this <= other;
     }
-    ['>='](other) {
+    [dartx['>=']](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
       return this >= other;
     }
-    get runtimeType() {
+    get [dartx.runtimeType]() {
       return core.num;
     }
   }
   JSNumber[dart.implements] = () => [core.num];
   dart.setSignature(JSNumber, {
     constructors: () => ({JSNumber: [JSNumber, []]}),
     methods: () => ({
-      compareTo: [core.int, [core.num]],
-      remainder: [core.num, [core.num]],
-      abs: [core.num, []],
-      toInt: [core.int, []],
-      truncate: [core.int, []],
-      ceil: [core.int, []],
-      floor: [core.int, []],
-      round: [core.int, []],
-      ceilToDouble: [core.double, []],
-      floorToDouble: [core.double, []],
-      roundToDouble: [core.double, []],
-      truncateToDouble: [core.double, []],
-      clamp: [core.num, [core.num, core.num]],
-      toDouble: [core.double, []],
-      toStringAsFixed: [core.String, [core.int]],
-      toStringAsExponential: [core.String, [], [core.int]],
-      toStringAsPrecision: [core.String, [core.int]],
-      toRadixString: [core.String, [core.int]],
-      'unary-': [core.num, []],
-      '+': [core.num, [core.num]],
-      '-': [core.num, [core.num]],
-      '/': [core.double, [core.num]],
-      '*': [core.num, [core.num]],
-      '%': [core.num, [core.num]],
+      [dartx.compareTo]: [core.int, [core.num]],
+      [dartx.remainder]: [core.num, [core.num]],
+      [dartx.abs]: [core.num, []],
+      [dartx.toInt]: [core.int, []],
+      [dartx.truncate]: [core.int, []],
+      [dartx.ceil]: [core.int, []],
+      [dartx.floor]: [core.int, []],
+      [dartx.round]: [core.int, []],
+      [dartx.ceilToDouble]: [core.double, []],
+      [dartx.floorToDouble]: [core.double, []],
+      [dartx.roundToDouble]: [core.double, []],
+      [dartx.truncateToDouble]: [core.double, []],
+      [dartx.clamp]: [core.num, [core.num, core.num]],
+      [dartx.toDouble]: [core.double, []],
+      [dartx.toStringAsFixed]: [core.String, [core.int]],
+      [dartx.toStringAsExponential]: [core.String, [], [core.int]],
+      [dartx.toStringAsPrecision]: [core.String, [core.int]],
+      [dartx.toRadixString]: [core.String, [core.int]],
+      [dartx['unary-']]: [core.num, []],
+      [dartx['+']]: [core.num, [core.num]],
+      [dartx['-']]: [core.num, [core.num]],
+      [dartx['/']]: [core.double, [core.num]],
+      [dartx['*']]: [core.num, [core.num]],
+      [dartx['%']]: [core.num, [core.num]],
       [_isInt32]: [core.bool, [core.Object]],
-      '~/': [core.int, [core.num]],
+      [dartx['~/']]: [core.int, [core.num]],
       [_tdivFast]: [core.int, [core.num]],
       [_tdivSlow]: [core.int, [core.num]],
-      '<<': [core.num, [core.num]],
+      [dartx['<<']]: [core.num, [core.num]],
       [_shlPositive]: [core.num, [core.num]],
-      '>>': [core.num, [core.num]],
+      [dartx['>>']]: [core.num, [core.num]],
       [_shrOtherPositive]: [core.num, [core.num]],
       [_shrReceiverPositive]: [core.num, [core.num]],
       [_shrBothPositive]: [core.num, [core.num]],
-      '&': [core.num, [core.num]],
-      '|': [core.num, [core.num]],
-      '^': [core.num, [core.num]],
-      '<': [core.bool, [core.num]],
-      '>': [core.bool, [core.num]],
-      '<=': [core.bool, [core.num]],
-      '>=': [core.bool, [core.num]]
+      [dartx['&']]: [core.num, [core.num]],
+      [dartx['|']]: [core.num, [core.num]],
+      [dartx['^']]: [core.num, [core.num]],
+      [dartx['<']]: [core.bool, [core.num]],
+      [dartx['>']]: [core.bool, [core.num]],
+      [dartx['<=']]: [core.bool, [core.num]],
+      [dartx['>=']]: [core.bool, [core.num]]
     }),
     statics: () => ({_handleIEtoString: [core.String, [core.String]]}),
     names: ['_handleIEtoString']
   });
   JSNumber._MIN_INT32 = -2147483648;
   JSNumber._MAX_INT32 = 2147483647;
+  dart.defineExtensionNames([
+    'isEven',
+    'isOdd',
+    'toUnsigned',
+    'toSigned',
+    'bitLength',
+    'runtimeType',
+    '~'
+  ]);
   class JSInt extends JSNumber {
     JSInt() {
       super.JSNumber();
     }
-    get isEven() {
+    get [dartx.isEven]() {
       return this[dartx['&']](1) == 0;
     }
-    get isOdd() {
+    get [dartx.isOdd]() {
       return this[dartx['&']](1) == 1;
     }
-    toUnsigned(width) {
+    [dartx.toUnsigned](width) {
       return this[dartx['&']]((1 << dart.notNull(width)) - 1);
     }
-    toSigned(width) {
+    [dartx.toSigned](width) {
       let signMask = 1 << dart.notNull(width) - 1;
       return dart.notNull(this[dartx['&']](dart.notNull(signMask) - 1)) - dart.notNull(this[dartx['&']](signMask));
     }
-    get bitLength() {
+    get [dartx.bitLength]() {
       let nonneg = dart.notNull(this[dartx['<']](0)) ? dart.notNull(this[dartx['unary-']]()) - 1 : this;
       if (dart.notNull(nonneg) >= 4294967296) {
         nonneg = (dart.notNull(nonneg) / 4294967296).truncate();
         return dart.notNull(JSInt._bitCount(JSInt._spread(nonneg))) + 32;
       }
       return JSInt._bitCount(JSInt._spread(nonneg));
     }
     static _bitCount(i) {
       i = dart.notNull(JSInt._shru(i, 0)) - (dart.notNull(JSInt._shru(i, 1)) & 1431655765);
       i = (dart.notNull(i) & 858993459) + (dart.notNull(JSInt._shru(i, 2)) & 858993459);
@@ skipping 12 matching lines @@
       return a | b;
     }
     static _spread(i) {
       i = JSInt._ors(i, JSInt._shrs(i, 1));
       i = JSInt._ors(i, JSInt._shrs(i, 2));
       i = JSInt._ors(i, JSInt._shrs(i, 4));
       i = JSInt._ors(i, JSInt._shrs(i, 8));
       i = JSInt._shru(JSInt._ors(i, JSInt._shrs(i, 16)), 0);
       return i;
     }
-    get runtimeType() {
+    get [dartx.runtimeType]() {
       return core.int;
     }
-    ['~']() {
+    [dartx['~']]() {
       return dart.as(~this >>> 0, core.int);
     }
   }
   JSInt[dart.implements] = () => [core.int, core.double];
   dart.setSignature(JSInt, {
     constructors: () => ({JSInt: [JSInt, []]}),
     methods: () => ({
-      toUnsigned: [core.int, [core.int]],
-      toSigned: [core.int, [core.int]],
-      '~': [core.int, []]
+      [dartx.toUnsigned]: [core.int, [core.int]],
+      [dartx.toSigned]: [core.int, [core.int]],
+      [dartx['~']]: [core.int, []]
     }),
     statics: () => ({
       _bitCount: [core.int, [core.int]],
       _shru: [core.int, [core.int, core.int]],
       _shrs: [core.int, [core.int, core.int]],
       _ors: [core.int, [core.int, core.int]],
       _spread: [core.int, [core.int]]
     }),
     names: ['_bitCount', '_shru', '_shrs', '_ors', '_spread']
   });
   dart.registerExtension(dart.global.Number, JSInt);
   class JSDouble extends JSNumber {
     JSDouble() {
       super.JSNumber();
     }
-    get runtimeType() {
+    get [dartx.runtimeType]() {
       return core.double;
     }
   }
   JSDouble[dart.implements] = () => [core.double];
   dart.setSignature(JSDouble, {
     constructors: () => ({JSDouble: [JSDouble, []]})
   });
   class JSPositiveInt extends JSInt {
     JSPositiveInt() {
       super.JSInt();
     }
   }
   class JSUInt32 extends JSPositiveInt {}
   class JSUInt31 extends JSUInt32 {}
   let _defaultSplit = Symbol('_defaultSplit');
+  dart.defineExtensionNames([
+    'codeUnitAt',
+    'allMatches',
+    'matchAsPrefix',
+    '+',
+    'endsWith',
+    'replaceAll',
+    'replaceAllMapped',
+    'splitMapJoin',
+    'replaceFirst',
+    'split',
+    'startsWith',
+    'substring',
+    'toLowerCase',
+    'toUpperCase',
+    'trim',
+    'trimLeft',
+    'trimRight',
+    '*',
+    'padLeft',
+    'padRight',
+    'codeUnits',
+    'runes',
+    'indexOf',
+    'lastIndexOf',
+    'contains',
+    'isEmpty',
+    'isNotEmpty',
+    'compareTo',
+    'toString',
+    'hashCode',
+    'runtimeType',
+    'length',
+    'get'
+  ]);
   class JSString extends Interceptor {
     JSString() {
       super.Interceptor();
     }
-    codeUnitAt(index) {
+    [dartx.codeUnitAt](index) {
       if (!(typeof index == 'number'))
         throw new core.ArgumentError(index);
       if (dart.notNull(index) < 0)
         throw new core.RangeError.value(index);
       if (dart.notNull(index) >= dart.notNull(this.length))
         throw new core.RangeError.value(index);
       return dart.as(this.charCodeAt(index), core.int);
     }
-    allMatches(string, start) {
+    [dartx.allMatches](string, start) {
       if (start === void 0)
         start = 0;
       _js_helper.checkString(string);
       _js_helper.checkInt(start);
       if (0 > dart.notNull(start) || dart.notNull(start) > dart.notNull(string.length)) {
         throw new core.RangeError.range(start, 0, string.length);
       }
       return _js_helper.allMatchesInStringUnchecked(this, string, start);
     }
-    matchAsPrefix(string, start) {
+    [dartx.matchAsPrefix](string, start) {
       if (start === void 0)
         start = 0;
       if (dart.notNull(start) < 0 || dart.notNull(start) > dart.notNull(string.length)) {
         throw new core.RangeError.range(start, 0, string.length);
       }
       if (dart.notNull(start) + dart.notNull(this.length) > dart.notNull(string.length))
         return null;
       for (let i = 0; dart.notNull(i) < dart.notNull(this.length); i = dart.notNull(i) + 1) {
         if (string[dartx.codeUnitAt](dart.notNull(start) + dart.notNull(i)) != this[dartx.codeUnitAt](i)) {
           return null;
         }
       }
       return new _js_helper.StringMatch(start, string, this);
     }
-    ['+'](other) {
+    [dartx['+']](other) {
       if (!(typeof other == 'string'))
         throw new core.ArgumentError(other);
       return this + other;
     }
-    endsWith(other) {
+    [dartx.endsWith](other) {
       _js_helper.checkString(other);
       let otherLength = other.length;
       if (dart.notNull(otherLength) > dart.notNull(this.length))
         return false;
       return other == this[dartx.substring](dart.notNull(this.length) - dart.notNull(otherLength));
     }
-    replaceAll(from, to) {
+    [dartx.replaceAll](from, to) {
       _js_helper.checkString(to);
       return dart.as(_js_helper.stringReplaceAllUnchecked(this, from, to), core.String);
     }
-    replaceAllMapped(from, convert) {
+    [dartx.replaceAllMapped](from, convert) {
       return this[dartx.splitMapJoin](from, {onMatch: convert});
     }
-    splitMapJoin(from, opts) {
+    [dartx.splitMapJoin](from, opts) {
       let onMatch = opts && 'onMatch' in opts ? opts.onMatch : null;
       let onNonMatch = opts && 'onNonMatch' in opts ? opts.onNonMatch : null;
       return dart.as(_js_helper.stringReplaceAllFuncUnchecked(this, from, onMatch, onNonMatch), core.String);
     }
-    replaceFirst(from, to, startIndex) {
+    [dartx.replaceFirst](from, to, startIndex) {
       if (startIndex === void 0)
         startIndex = 0;
       _js_helper.checkString(to);
       _js_helper.checkInt(startIndex);
       if (dart.notNull(startIndex) < 0 || dart.notNull(startIndex) > dart.notNull(this.length)) {
         throw new core.RangeError.range(startIndex, 0, this.length);
       }
       return dart.as(_js_helper.stringReplaceFirstUnchecked(this, from, to, startIndex), core.String);
     }
-    split(pattern) {
+    [dartx.split](pattern) {
       _js_helper.checkNull(pattern);
       if (typeof pattern == 'string') {
         return dart.as(this.split(pattern), core.List$(core.String));
       } else if (dart.is(pattern, _js_helper.JSSyntaxRegExp) && _js_helper.regExpCaptureCount(pattern) == 0) {
         let re = _js_helper.regExpGetNative(pattern);
         return dart.as(this.split(re), core.List$(core.String));
       } else {
         return this[_defaultSplit](pattern);
       }
     }
@@ skipping 10 matching lines @@
         }
         let end = matchStart;
         result[dartx.add](this[dartx.substring](start, end));
         start = matchEnd;
       }
       if (dart.notNull(start) < dart.notNull(this.length) || dart.notNull(length) > 0) {
         result[dartx.add](this[dartx.substring](start));
       }
       return result;
     }
-    startsWith(pattern, index) {
+    [dartx.startsWith](pattern, index) {
       if (index === void 0)
         index = 0;
       _js_helper.checkInt(index);
       if (dart.notNull(index) < 0 || dart.notNull(index) > dart.notNull(this.length)) {
         throw new core.RangeError.range(index, 0, this.length);
       }
       if (typeof pattern == 'string') {
         let other = pattern;
         let otherLength = other.length;
         let endIndex = dart.notNull(index) + dart.notNull(otherLength);
         if (dart.notNull(endIndex) > dart.notNull(this.length))
           return false;
         return other == this.substring(index, endIndex);
       }
       return pattern[dartx.matchAsPrefix](this, index) != null;
     }
-    substring(startIndex, endIndex) {
+    [dartx.substring](startIndex, endIndex) {
       if (endIndex === void 0)
         endIndex = null;
       _js_helper.checkInt(startIndex);
       if (endIndex == null)
         endIndex = this.length;
       _js_helper.checkInt(endIndex);
       if (dart.notNull(startIndex) < 0)
         throw new core.RangeError.value(startIndex);
       if (dart.notNull(startIndex) > dart.notNull(endIndex))
         throw new core.RangeError.value(startIndex);
       if (dart.notNull(endIndex) > dart.notNull(this.length))
         throw new core.RangeError.value(endIndex);
       return this.substring(startIndex, endIndex);
     }
-    toLowerCase() {
+    [dartx.toLowerCase]() {
       return this.toLowerCase();
     }
-    toUpperCase() {
+    [dartx.toUpperCase]() {
       return this.toUpperCase();
     }
     static _isWhitespace(codeUnit) {
       if (dart.notNull(codeUnit) < 256) {
         switch (codeUnit) {
           case 9:
           case 10:
           case 11:
           case 12:
           case 13:
@@ skipping 55 matching lines @@
       let CARRIAGE_RETURN = 13;
       while (dart.notNull(index) > 0) {
         let codeUnit = string[dartx.codeUnitAt](dart.notNull(index) - 1);
         if (codeUnit != SPACE && codeUnit != CARRIAGE_RETURN && !dart.notNull(JSString._isWhitespace(codeUnit))) {
           break;
         }
         index = dart.notNull(index) - 1;
       }
       return index;
     }
-    trim() {
+    [dartx.trim]() {
       let NEL = 133;
       let result = this.trim();
       if (result.length == 0)
         return result;
       let firstCode = result[dartx.codeUnitAt](0);
       let startIndex = 0;
       if (firstCode == NEL) {
         startIndex = JSString._skipLeadingWhitespace(result, 1);
         if (startIndex == result.length)
           return "";
       }
       let endIndex = result.length;
       let lastCode = result[dartx.codeUnitAt](dart.notNull(endIndex) - 1);
       if (lastCode == NEL) {
         endIndex = JSString._skipTrailingWhitespace(result, dart.notNull(endIndex) - 1);
       }
       if (startIndex == 0 && endIndex == result.length)
         return result;
       return result.substring(startIndex, endIndex);
     }
-    trimLeft() {
+    [dartx.trimLeft]() {
       let NEL = 133;
       let result = null;
       let startIndex = 0;
       if (typeof this.trimLeft != "undefined") {
         result = this.trimLeft();
         if (result.length == 0)
           return result;
         let firstCode = result[dartx.codeUnitAt](0);
         if (firstCode == NEL) {
           startIndex = JSString._skipLeadingWhitespace(result, 1);
         }
       } else {
         result = this;
         startIndex = JSString._skipLeadingWhitespace(this, 0);
       }
       if (startIndex == 0)
         return result;
       if (startIndex == result.length)
         return "";
       return result.substring(startIndex);
     }
-    trimRight() {
+    [dartx.trimRight]() {
       let NEL = 133;
       let result = null;
       let endIndex = null;
       if (typeof this.trimRight != "undefined") {
         result = this.trimRight();
         endIndex = result.length;
         if (endIndex == 0)
           return result;
         let lastCode = result[dartx.codeUnitAt](dart.notNull(endIndex) - 1);
         if (lastCode == NEL) {
           endIndex = JSString._skipTrailingWhitespace(result, dart.notNull(endIndex) - 1);
         }
       } else {
         result = this;
         endIndex = JSString._skipTrailingWhitespace(this, this.length);
       }
       if (endIndex == result.length)
         return result;
       if (endIndex == 0)
         return "";
       return result.substring(0, endIndex);
     }
-    ['*'](times) {
+    [dartx['*']](times) {
       if (0 >= dart.notNull(times))
         return '';
       if (times == 1 || this.length == 0)
         return this;
       if (!dart.equals(times, times >>> 0)) {
         throw dart.const(new core.OutOfMemoryError());
       }
       let result = '';
       let s = this;
       while (true) {
         if ((dart.notNull(times) & 1) == 1)
           result = s[dartx['+']](result);
         times = dart.as(times >>> 1, core.int);
         if (times == 0)
           break;
         s = s[dartx['+']](s);
       }
       return result;
     }
-    padLeft(width, padding) {
+    [dartx.padLeft](width, padding) {
       if (padding === void 0)
         padding = ' ';
       let delta = dart.notNull(width) - dart.notNull(this.length);
       if (dart.notNull(delta) <= 0)
         return this;
       return padding[dartx['*']](delta) + this;
     }
-    padRight(width, padding) {
+    [dartx.padRight](width, padding) {
       if (padding === void 0)
         padding = ' ';
       let delta = dart.notNull(width) - dart.notNull(this.length);
       if (dart.notNull(delta) <= 0)
         return this;
       return this[dartx['+']](padding[dartx['*']](delta));
     }
-    get codeUnits() {
+    get [dartx.codeUnits]() {
       return new _CodeUnits(this);
     }
-    get runes() {
+    get [dartx.runes]() {
       return new core.Runes(this);
     }
-    indexOf(pattern, start) {
+    [dartx.indexOf](pattern, start) {
       if (start === void 0)
         start = 0;
       _js_helper.checkNull(pattern);
       if (!(typeof start == 'number'))
         throw new core.ArgumentError(start);
       if (dart.notNull(start) < 0 || dart.notNull(start) > dart.notNull(this.length)) {
         throw new core.RangeError.range(start, 0, this.length);
       }
       if (typeof pattern == 'string') {
         return this.indexOf(pattern, start);
       }
       if (dart.is(pattern, _js_helper.JSSyntaxRegExp)) {
         let re = pattern;
         let match = _js_helper.firstMatchAfter(re, this, start);
         return match == null ? -1 : match.start;
       }
       for (let i = start; dart.notNull(i) <= dart.notNull(this.length); i = dart.notNull(i) + 1) {
         if (pattern[dartx.matchAsPrefix](this, i) != null)
           return i;
       }
       return -1;
     }
-    lastIndexOf(pattern, start) {
+    [dartx.lastIndexOf](pattern, start) {
       if (start === void 0)
         start = null;
       _js_helper.checkNull(pattern);
       if (start == null) {
         start = this.length;
       } else if (!(typeof start == 'number')) {
         throw new core.ArgumentError(start);
       } else if (dart.notNull(start) < 0 || dart.notNull(start) > dart.notNull(this.length)) {
         throw new core.RangeError.range(start, 0, this.length);
       }
       if (typeof pattern == 'string') {
         let other = pattern;
         if (dart.notNull(start) + dart.notNull(other.length) > dart.notNull(this.length)) {
           start = dart.notNull(this.length) - dart.notNull(other.length);
         }
         return dart.as(_js_helper.stringLastIndexOfUnchecked(this, other, start), core.int);
       }
       for (let i = start; dart.notNull(i) >= 0; i = dart.notNull(i) - 1) {
         if (pattern[dartx.matchAsPrefix](this, i) != null)
           return i;
       }
       return -1;
     }
-    contains(other, startIndex) {
+    [dartx.contains](other, startIndex) {
       if (startIndex === void 0)
         startIndex = 0;
       _js_helper.checkNull(other);
       if (dart.notNull(startIndex) < 0 || dart.notNull(startIndex) > dart.notNull(this.length)) {
         throw new core.RangeError.range(startIndex, 0, this.length);
       }
       return dart.as(_js_helper.stringContainsUnchecked(this, other, startIndex), core.bool);
     }
-    get isEmpty() {
+    get [dartx.isEmpty]() {
       return this.length == 0;
     }
-    get isNotEmpty() {
+    get [dartx.isNotEmpty]() {
       return !dart.notNull(this[dartx.isEmpty]);
     }
-    compareTo(other) {
+    [dartx.compareTo](other) {
       if (!(typeof other == 'string'))
         throw new core.ArgumentError(other);
       return dart.equals(this, other) ? 0 : this < other ? -1 : 1;
     }
-    toString() {
+    [dartx.toString]() {
       return this;
     }
-    get hashCode() {
+    get [dartx.hashCode]() {
       let hash = 0;
       for (let i = 0; dart.notNull(i) < dart.notNull(this.length); i = dart.notNull(i) + 1) {
         hash = 536870911 & dart.notNull(hash) + this.charCodeAt(i);
         hash = 536870911 & dart.notNull(hash) + ((524287 & dart.notNull(hash)) << 10);
         hash = hash ^ hash >> 6;
       }
       hash = 536870911 & dart.notNull(hash) + ((67108863 & dart.notNull(hash)) << 3);
       hash = hash ^ hash >> 11;
       return 536870911 & dart.notNull(hash) + ((16383 & dart.notNull(hash)) << 15);
     }
-    get runtimeType() {
+    get [dartx.runtimeType]() {
       return core.String;
     }
     get length() {
       return this.length;
     }
-    get(index) {
+    [dartx.get](index) {
       if (!(typeof index == 'number'))
         throw new core.ArgumentError(index);
       if (dart.notNull(index) >= dart.notNull(this.length) || dart.notNull(index) < 0)
         throw new core.RangeError.value(index);
       return this[index];
     }
   }
   JSString[dart.implements] = () => [core.String, JSIndexable];
   dart.setSignature(JSString, {
     constructors: () => ({JSString: [JSString, []]}),
     methods: () => ({
-      codeUnitAt: [core.int, [core.int]],
-      allMatches: [core.Iterable$(core.Match), [core.String], [core.int]],
-      matchAsPrefix: [core.Match, [core.String], [core.int]],
-      '+': [core.String, [core.String]],
-      endsWith: [core.bool, [core.String]],
-      replaceAll: [core.String, [core.Pattern, core.String]],
-      replaceAllMapped: [core.String, [core.Pattern, dart.functionType(core.String, [core.Match])]],
-      splitMapJoin: [core.String, [core.Pattern], {onMatch: dart.functionType(core.String, [core.Match]), onNonMatch: dart.functionType(core.String, [core.String])}],
-      replaceFirst: [core.String, [core.Pattern, core.String], [core.int]],
-      split: [core.List$(core.String), [core.Pattern]],
+      [dartx.codeUnitAt]: [core.int, [core.int]],
+      [dartx.allMatches]: [core.Iterable$(core.Match), [core.String], [core.int]],
+      [dartx.matchAsPrefix]: [core.Match, [core.String], [core.int]],
+      [dartx['+']]: [core.String, [core.String]],
+      [dartx.endsWith]: [core.bool, [core.String]],
+      [dartx.replaceAll]: [core.String, [core.Pattern, core.String]],
+      [dartx.replaceAllMapped]: [core.String, [core.Pattern, dart.functionType(core.String, [core.Match])]],
+      [dartx.splitMapJoin]: [core.String, [core.Pattern], {onMatch: dart.functionType(core.String, [core.Match]), onNonMatch: dart.functionType(core.String, [core.String])}],
+      [dartx.replaceFirst]: [core.String, [core.Pattern, core.String], [core.int]],
+      [dartx.split]: [core.List$(core.String), [core.Pattern]],
       [_defaultSplit]: [core.List$(core.String), [core.Pattern]],
-      startsWith: [core.bool, [core.Pattern], [core.int]],
-      substring: [core.String, [core.int], [core.int]],
-      toLowerCase: [core.String, []],
-      toUpperCase: [core.String, []],
-      trim: [core.String, []],
-      trimLeft: [core.String, []],
-      trimRight: [core.String, []],
-      '*': [core.String, [core.int]],
-      padLeft: [core.String, [core.int], [core.String]],
-      padRight: [core.String, [core.int], [core.String]],
-      indexOf: [core.int, [core.Pattern], [core.int]],
-      lastIndexOf: [core.int, [core.Pattern], [core.int]],
-      contains: [core.bool, [core.Pattern], [core.int]],
-      compareTo: [core.int, [core.String]],
-      get: [core.String, [core.int]]
+      [dartx.startsWith]: [core.bool, [core.Pattern], [core.int]],
+      [dartx.substring]: [core.String, [core.int], [core.int]],
+      [dartx.toLowerCase]: [core.String, []],
+      [dartx.toUpperCase]: [core.String, []],
+      [dartx.trim]: [core.String, []],
+      [dartx.trimLeft]: [core.String, []],
+      [dartx.trimRight]: [core.String, []],
+      [dartx['*']]: [core.String, [core.int]],
+      [dartx.padLeft]: [core.String, [core.int], [core.String]],
+      [dartx.padRight]: [core.String, [core.int], [core.String]],
+      [dartx.indexOf]: [core.int, [core.Pattern], [core.int]],
+      [dartx.lastIndexOf]: [core.int, [core.Pattern], [core.int]],
+      [dartx.contains]: [core.bool, [core.Pattern], [core.int]],
+      [dartx.compareTo]: [core.int, [core.String]],
+      [dartx.get]: [core.String, [core.int]]
     }),
     statics: () => ({
       _isWhitespace: [core.bool, [core.int]],
       _skipLeadingWhitespace: [core.int, [core.String, core.int]],
       _skipTrailingWhitespace: [core.int, [core.String, core.int]]
     }),
     names: ['_isWhitespace', '_skipLeadingWhitespace', '_skipTrailingWhitespace']
   });
   dart.registerExtension(dart.global.String, JSString);
   let _string = Symbol('_string');
   class _CodeUnits extends _internal.UnmodifiableListBase$(core.int) {
     _CodeUnits(string) {
       this[_string] = string;
     }
     get length() {
       return this[_string].length;
     }
     get(i) {
       return this[_string][dartx.codeUnitAt](i);
     }
   }
   dart.setSignature(_CodeUnits, {
     constructors: () => ({_CodeUnits: [_CodeUnits, [core.String]]}),
     methods: () => ({get: [core.int, [core.int]]})
   });
+  dart.defineExtensionMembers(_CodeUnits, ['get', 'length']);
   function getInterceptor(obj) {
     return obj;
   }
   dart.fn(getInterceptor);
+  dart.defineExtensionNames([
+    'toString',
+    'hashCode',
+    'runtimeType'
+  ]);
   class JSBool extends Interceptor {
     JSBool() {
       super.Interceptor();
     }
-    toString() {
+    [dartx.toString]() {
       return String(this);
     }
-    get hashCode() {
+    get [dartx.hashCode]() {
       return this ? 2 * 3 * 23 * 3761 : 269 * 811;
     }
-    get runtimeType() {
+    get [dartx.runtimeType]() {
       return core.bool;
     }
   }
   JSBool[dart.implements] = () => [core.bool];
   dart.setSignature(JSBool, {
     constructors: () => ({JSBool: [JSBool, []]})
   });
   dart.registerExtension(dart.global.Boolean, JSBool);
   class JSIndexable extends core.Object {}
   class JSMutableIndexable extends JSIndexable {}
@@ skipping 51 matching lines @@
   exports.JSString = JSString;
   exports.getInterceptor = getInterceptor;
   exports.JSBool = JSBool;
   exports.JSIndexable = JSIndexable;
   exports.JSMutableIndexable = JSMutableIndexable;
   exports.JSObject = JSObject;
   exports.JavaScriptObject = JavaScriptObject;
   exports.PlainJavaScriptObject = PlainJavaScriptObject;
   exports.UnknownJavaScriptObject = UnknownJavaScriptObject;
 })(_interceptors, core, _internal, _js_helper, collection, math);