support the JS builtin

test/codegen/expect/_interceptors/_interceptors.js

 var _interceptors;
 (function(_interceptors) {
   'use strict';
   // Function _symbolToString: (Symbol) → String
   function _symbolToString(symbol) {
     return _internal.Symbol.getName(dart.as(symbol, _internal.Symbol));
   }
   // Function _symbolMapToStringMap: (Map<Symbol, dynamic>) → dynamic
   function _symbolMapToStringMap(map) {
     if (map === null)
       return null;
     let result = new core.Map();
     map.forEach((key, value) => {
       result.set(_symbolToString(key), value);
     });
     return result;
   }
   // Function getInterceptor: (dynamic) → dynamic
   function getInterceptor(object) {
-    return _foreign_helper.JS('', 'void 0');
+    return void 0;
   }
   // Function getDispatchProperty: (dynamic) → dynamic
   function getDispatchProperty(object) {
-    return _foreign_helper.JS('', '#[#]', object, _foreign_helper.JS_EMBEDDED_GLOBAL('String', dart.as(_js_embedded_names.DISPATCH_PROPERTY_NAME, core.String)));
+    return object[_foreign_helper.JS_EMBEDDED_GLOBAL('String', dart.as(_js_embedded_names.DISPATCH_PROPERTY_NAME, core.String))];
   }
   // Function setDispatchProperty: (dynamic, dynamic) → dynamic
   function setDispatchProperty(object, value) {
     _js_helper.defineProperty(object, dart.as(_foreign_helper.JS_EMBEDDED_GLOBAL('String', dart.as(_js_embedded_names.DISPATCH_PROPERTY_NAME, core.String)), core.String), value);
   }
   // Function makeDispatchRecord: (dynamic, dynamic, dynamic, dynamic) → dynamic
   function makeDispatchRecord(interceptor, proto, extension, indexability) {
-    return _foreign_helper.JS('', '{i: #, p: #, e: #, x: #}', interceptor, proto, extension, indexability);
+    return {i: interceptor, p: proto, e: extension, x: indexability};
   }
   // Function dispatchRecordInterceptor: (dynamic) → dynamic
   function dispatchRecordInterceptor(record) {
-    return _foreign_helper.JS('', '#.i', record);
+    return record.i;
   }
   // Function dispatchRecordProto: (dynamic) → dynamic
   function dispatchRecordProto(record) {
-    return _foreign_helper.JS('', '#.p', record);
+    return record.p;
   }
   // Function dispatchRecordExtension: (dynamic) → dynamic
   function dispatchRecordExtension(record) {
-    return _foreign_helper.JS('', '#.e', record);
+    return record.e;
   }
   // Function dispatchRecordIndexability: (dynamic) → dynamic
   function dispatchRecordIndexability(record) {
-    return _foreign_helper.JS('bool|Null', '#.x', record);
+    return record.x;
   }
   // Function getNativeInterceptor: (dynamic) → dynamic
   function getNativeInterceptor(object) {
     let record = getDispatchProperty(object);
     if (record === null) {
       if (_js_helper.initNativeDispatchFlag === null) {
         _js_helper.initNativeDispatch();
         record = getDispatchProperty(object);
       }
     }
     if (record !== null) {
       let proto = dispatchRecordProto(record);
       if (false === proto)
         return dispatchRecordInterceptor(record);
       if (true === proto)
         return object;
-      let objectProto = _foreign_helper.JS('', 'Object.getPrototypeOf(#)', object);
-      if (_foreign_helper.JS('bool', '# === #', proto, objectProto)) {
+      let objectProto = Object.getPrototypeOf(object);
+      if (proto === objectProto) {
         return dispatchRecordInterceptor(record);
       }
       let extension = dispatchRecordExtension(record);
-      if (_foreign_helper.JS('bool', '# === #', extension, objectProto)) {
-        let discriminatedTag = _foreign_helper.JS('', '(#)(#, #)', proto, object, record);
+      if (extension === objectProto) {
+        let discriminatedTag = proto(object, record);
         throw new core.UnimplementedError(`Return interceptor for ${discriminatedTag}`);
       }
     }
     let interceptor = _js_helper.lookupAndCacheInterceptor(object);
     if (interceptor === null) {
-      let proto = _foreign_helper.JS('', 'Object.getPrototypeOf(#)', object);
-      if (_foreign_helper.JS('bool', '# == null || # === Object.prototype', proto, proto)) {
+      let proto = Object.getPrototypeOf(object);
+      if (proto == null || proto === Object.prototype) {
         return _foreign_helper.JS_INTERCEPTOR_CONSTANT(PlainJavaScriptObject);
       } else {
         return _foreign_helper.JS_INTERCEPTOR_CONSTANT(UnknownJavaScriptObject);
       }
     }
     return interceptor;
   }
   dart.copyProperties(_interceptors, {
     get mapTypeToInterceptor() {
       return _foreign_helper.JS_EMBEDDED_GLOBAL('', dart.as(_js_embedded_names.MAP_TYPE_TO_INTERCEPTOR, core.String));
     }
   });
   // Function findIndexForNativeSubclassType: (Type) → int
   function findIndexForNativeSubclassType(type) {
-    if (_foreign_helper.JS('bool', '# == null', _interceptors.mapTypeToInterceptor))
+    if (_interceptors.mapTypeToInterceptor == null)
       return dart.as(null, core.int);
-    let map = dart.as(_foreign_helper.JS('JSFixedArray', '#', _interceptors.mapTypeToInterceptor), core.List);
+    let map = dart.as(_interceptors.mapTypeToInterceptor, core.List);
     for (let i = 0; i + 1 < map.length; i = 3) {
       if (dart.equals(type, map.get(i))) {
         return i;
       }
     }
     return dart.as(null, core.int);
   }
   // Function findInterceptorConstructorForType: (Type) → dynamic
   function findInterceptorConstructorForType(type) {
     let index = findIndexForNativeSubclassType(type);
     if (index === null)
       return null;
-    let map = dart.as(_foreign_helper.JS('JSFixedArray', '#', _interceptors.mapTypeToInterceptor), core.List);
+    let map = dart.as(_interceptors.mapTypeToInterceptor, core.List);
     return map.get(index + 1);
   }
   // Function findConstructorForNativeSubclassType: (Type, String) → dynamic
   function findConstructorForNativeSubclassType(type, name) {
     let index = findIndexForNativeSubclassType(type);
     if (index === null)
       return null;
-    let map = dart.as(_foreign_helper.JS('JSFixedArray', '#', _interceptors.mapTypeToInterceptor), core.List);
+    let map = dart.as(_interceptors.mapTypeToInterceptor, core.List);
     let constructorMap = map.get(index + 2);
-    let constructorFn = _foreign_helper.JS('', '#[#]', constructorMap, name);
+    let constructorFn = constructorMap[name];
     return constructorFn;
   }
   // Function findInterceptorForType: (Type) → dynamic
   function findInterceptorForType(type) {
     let constructor = findInterceptorConstructorForType(type);
     if (constructor === null)
       return null;
-    return _foreign_helper.JS('', '#.prototype', constructor);
+    return constructor.prototype;
   }
   class Interceptor extends dart.Object {
     Interceptor() {
     }
     ['=='](other) {
       return core.identical(this, other);
     }
     get hashCode() {
       return _js_helper.Primitives.objectHashCode(this);
     }
     toString() {
       return _js_helper.Primitives.objectToString(this);
     }
     noSuchMethod(invocation) {
       throw new core.NoSuchMethodError(this, invocation.memberName, invocation.positionalArguments, invocation.namedArguments);
     }
     get runtimeType() {
       return _js_helper.getRuntimeType(this);
     }
   }
   class JSBool extends Interceptor {
     JSBool() {
       super.Interceptor();
     }
     toString() {
-      return dart.as(_foreign_helper.JS('String', 'String(#)', this), core.String);
+      return String(this);
     }
     get hashCode() {
       return this ? 2 * 3 * 23 * 3761 : 269 * 811;
     }
     get runtimeType() {
       return core.bool;
     }
   }
   class JSNull extends Interceptor {
     JSNull() {
@@ skipping 35 matching lines @@
   class PlainJavaScriptObject extends JavaScriptObject {
     PlainJavaScriptObject() {
       super.JavaScriptObject();
     }
   }
   class UnknownJavaScriptObject extends JavaScriptObject {
     UnknownJavaScriptObject() {
       super.JavaScriptObject();
     }
     toString() {
-      return dart.as(_foreign_helper.JS('String', 'String(#)', this), core.String);
+      return String(this);
     }
   }
   let JSArray$ = dart.generic(function(E) {
     class JSArray extends Interceptor {
       JSArray() {
         super.Interceptor();
       }
       JSArray$fixed(length) {
         if (dart.notNull(!(typeof length == number)) || dart.notNull(length < 0)) {
           throw new core.ArgumentError(`Length must be a non-negative integer: ${length}`);
         }
-        return new JSArray.markFixed(_foreign_helper.JS('', 'new Array(#)', length));
+        return new JSArray.markFixed(new Array(length));
       }
       JSArray$emptyGrowable() {
-        return new JSArray.markGrowable(_foreign_helper.JS('', '[]'));
+        return new JSArray.markGrowable([]);
       }
       JSArray$growable(length) {
         if (dart.notNull(!(typeof length == number)) || dart.notNull(length < 0)) {
           throw new core.ArgumentError(`Length must be a non-negative integer: ${length}`);
         }
-        return new JSArray.markGrowable(_foreign_helper.JS('', 'new Array(#)', length));
+        return new JSArray.markGrowable(new Array(length));
       }
       JSArray$typed(allocation) {
-        return dart.as(_foreign_helper.JS('JSArray', '#', allocation), JSArray$(E));
+        return dart.as(allocation, JSArray$(E));
       }
       JSArray$markFixed(allocation) {
-        return dart.as(_foreign_helper.JS('JSFixedArray', '#', markFixedList(new JSArray.typed(allocation))), JSArray$(E));
+        return dart.as(markFixedList(new JSArray.typed(allocation)), JSArray$(E));
       }
       JSArray$markGrowable(allocation) {
-        return dart.as(_foreign_helper.JS('JSExtendableArray', '#', new JSArray.typed(allocation)), JSArray$(E));
+        return dart.as(new JSArray.typed(allocation), JSArray$(E));
       }
       static markFixedList(list) {
-        _foreign_helper.JS('void', '#.fixed$length = Array', list);
-        return dart.as(_foreign_helper.JS('JSFixedArray', '#', list), core.List);
+        list.fixed$length = Array;
+        return dart.as(list, core.List);
       }
       checkMutable(reason) {
         if (!dart.is(this, JSMutableArray)) {
           throw new core.UnsupportedError(dart.as(reason, core.String));
         }
       }
       checkGrowable(reason) {
         if (!dart.is(this, JSExtendableArray)) {
           throw new core.UnsupportedError(dart.as(reason, core.String));
         }
       }
       add(value) {
         this.checkGrowable('add');
-        _foreign_helper.JS('void', '#.push(#)', this, value);
+        this.push(value);
       }
       removeAt(index) {
         if (!(typeof index == number))
           throw new core.ArgumentError(index);
         if (dart.notNull(index < 0) || dart.notNull(index >= this.length)) {
           throw new core.RangeError.value(index);
         }
         this.checkGrowable('removeAt');
-        return dart.as(_foreign_helper.JS('var', '#.splice(#, 1)[0]', this, index), E);
+        return dart.as(this.splice(index, 1)[0], E);
       }
       insert(index, value) {
         if (!(typeof index == number))
           throw new core.ArgumentError(index);
         if (dart.notNull(index < 0) || dart.notNull(index > this.length)) {
           throw new core.RangeError.value(index);
         }
         this.checkGrowable('insert');
-        _foreign_helper.JS('void', '#.splice(#, 0, #)', this, index, value);
+        this.splice(index, 0, value);
       }
       insertAll(index, iterable) {
         this.checkGrowable('insertAll');
         _internal.IterableMixinWorkaround.insertAllList(this, index, iterable);
       }
       setAll(index, iterable) {
         this.checkMutable('setAll');
         _internal.IterableMixinWorkaround.setAllList(this, index, iterable);
       }
       removeLast() {
         this.checkGrowable('removeLast');
         if (this.length === 0)
           throw new core.RangeError.value(-1);
-        return dart.as(_foreign_helper.JS('var', '#.pop()', this), E);
+        return dart.as(this.pop(), E);
       }
       remove(element) {
         this.checkGrowable('remove');
         for (let i = 0; i < this.length; i++) {
           if (dart.equals(this.get(i), element)) {
-            _foreign_helper.JS('var', '#.splice(#, 1)', this, i);
+            this.splice(i, 1);
             return true;
           }
         }
         return false;
       }
       removeWhere(test) {
         _internal.IterableMixinWorkaround.removeWhereList(this, dart.as(test, dart.throw_("Unimplemented type (dynamic) → bool")));
       }
       retainWhere(test) {
         _internal.IterableMixinWorkaround.removeWhereList(this, dart.as((element) => !dart.notNull(test(element)), dart.throw_("Unimplemented type (dynamic) → bool")));
       }
       where(f) {
         return new _internal.IterableMixinWorkaround().where(this, dart.as(f, dart.throw_("Unimplemented type (dynamic) → bool")));
       }
       expand(f) {
         return _internal.IterableMixinWorkaround.expand(this, dart.as(f, dart.throw_("Unimplemented type (dynamic) → Iterable<dynamic>")));
       }
       addAll(collection) {
         for (let e of collection) {
           this.add(e);
         }
       }
       clear() {
         this.length = 0;
       }
       forEach(f) {
         let length = this.length;
         for (let i = 0; i < length; i++) {
-          f(dart.as(_foreign_helper.JS('', '#[#]', this, i), E));
+          f(dart.as(this[i], E));
           if (length !== this.length) {
             throw new core.ConcurrentModificationError(this);
           }
         }
       }
       map(f) {
         return _internal.IterableMixinWorkaround.mapList(this, dart.as(f, dart.throw_("Unimplemented type (dynamic) → dynamic")));
       }
       join(separator) {
         if (separator === void 0)
           separator = "";
         let list = new core.List(this.length);
         for (let i = 0; i < this.length; i++) {
           list.set(i, `${this.get(i)}`);
         }
-        return dart.as(_foreign_helper.JS('String', "#.join(#)", list, separator), core.String);
+        return list.join(separator);
       }
       take(n) {
         return new _internal.IterableMixinWorkaround().takeList(this, n);
       }
       takeWhile(test) {
         return new _internal.IterableMixinWorkaround().takeWhile(this, dart.as(test, dart.throw_("Unimplemented type (dynamic) → bool")));
       }
       skip(n) {
         return new _internal.IterableMixinWorkaround().skipList(this, n);
       }
@@ skipping 33 matching lines @@
           end = this.length;
         } else {
           if (!(typeof end == number))
             throw new core.ArgumentError(end);
           if (dart.notNull(end < start) || dart.notNull(end > this.length)) {
             throw new core.RangeError.range(end, start, this.length);
           }
         }
         if (start === end)
           return new List.from([]);
-        return new JSArray.markGrowable(_foreign_helper.JS('', '#.slice(#, #)', this, start, end));
+        return new JSArray.markGrowable(this.slice(start, end));
       }
       getRange(start, end) {
         return new _internal.IterableMixinWorkaround().getRangeList(this, start, end);
       }
       get first() {
         if (this.length > 0)
           return this.get(0);
         throw new core.StateError("No elements");
       }
       get last() {
@@ skipping 78 matching lines @@
       }
       get isNotEmpty() {
         return !dart.notNull(this.isEmpty);
       }
       toString() {
         return collection.ListBase.listToString(this);
       }
       toList(opt$) {
         let growable = opt$.growable === void 0 ? true : opt$.growable;
         if (growable) {
-          return new JSArray.markGrowable(_foreign_helper.JS('', '#.slice()', this));
+          return new JSArray.markGrowable(this.slice());
         } else {
-          return new JSArray.markFixed(_foreign_helper.JS('', '#.slice()', this));
+          return new JSArray.markFixed(this.slice());
         }
       }
       toSet() {
         return new core.Set.from(this);
       }
       get iterator() {
         return new _internal.ListIterator(this);
       }
       get hashCode() {
         return _js_helper.Primitives.objectHashCode(this);
       }
       get length() {
-        return dart.as(_foreign_helper.JS('JSUInt32', '#.length', this), core.int);
+        return dart.as(this.length, core.int);
       }
       set length(newLength) {
         if (!(typeof newLength == number))
           throw new core.ArgumentError(newLength);
         if (newLength < 0)
           throw new core.RangeError.value(newLength);
         this.checkGrowable('set length');
-        _foreign_helper.JS('void', '#.length = #', this, newLength);
+        this.length = newLength;
       }
       get(index) {
         if (!(typeof index == number))
           throw new core.ArgumentError(index);
         if (dart.notNull(index >= this.length) || dart.notNull(index < 0))
           throw new core.RangeError.value(index);
-        return dart.as(_foreign_helper.JS('var', '#[#]', this, index), E);
+        return dart.as(this[index], E);
       }
       set(index, value) {
         this.checkMutable('indexed set');
         if (!(typeof index == number))
           throw new core.ArgumentError(index);
         if (dart.notNull(index >= this.length) || dart.notNull(index < 0))
           throw new core.RangeError.value(index);
-        _foreign_helper.JS('void', '#[#] = #', this, index, value);
+        this[index] = value;
       }
       asMap() {
         return new _internal.IterableMixinWorkaround().asMapList(this);
       }
     }
     dart.defineNamedConstructor(JSArray, 'fixed');
     dart.defineNamedConstructor(JSArray, 'emptyGrowable');
     dart.defineNamedConstructor(JSArray, 'growable');
     dart.defineNamedConstructor(JSArray, 'typed');
     dart.defineNamedConstructor(JSArray, 'markFixed');
@@ skipping 46 matching lines @@
         }
         return 1;
       } else {
         return -1;
       }
     }
     get isNegative() {
       return dart.equals(this, 0) ? 1['/'](this) < 0 : this['<'](0);
     }
     get isNaN() {
-      return dart.as(_foreign_helper.JS('bool', 'isNaN(#)', this), core.bool);
+      return isNaN(this);
     }
     get isInfinite() {
-      return dart.dbinary(_foreign_helper.JS('bool', '# == Infinity', this), '||', _foreign_helper.JS('bool', '# == -Infinity', this));
+      return dart.notNull(this == Infinity) || dart.notNull(this == -Infinity);
     }
     get isFinite() {
-      return dart.as(_foreign_helper.JS('bool', 'isFinite(#)', this), core.bool);
+      return isFinite(this);
     }
     remainder(b) {
       _js_helper.checkNull(b);
       if (!dart.is(b, core.num))
         throw new core.ArgumentError(b);
-      return dart.as(_foreign_helper.JS('num', '# % #', this, b), core.num);
+      return this % b;
     }
     abs() {
-      return dart.as(_foreign_helper.JS('num', 'Math.abs(#)', this), core.num);
+      return Math.abs(this);
     }
     get sign() {
       return this['>'](0) ? 1 : this['<'](0) ? -1 : this;
     }
     toInt() {
       if (dart.notNull(this['>='](_MIN_INT32)) && dart.notNull(this['<='](_MAX_INT32))) {
-        return dart.as(_foreign_helper.JS('int', '# | 0', this), core.int);
+        return this | 0;
       }
-      if (_foreign_helper.JS('bool', 'isFinite(#)', this)) {
-        return dart.as(_foreign_helper.JS('int', '# + 0', this.truncateToDouble()), core.int);
+      if (isFinite(this)) {
+        return this.truncateToDouble() + 0;
       }
-      throw new core.UnsupportedError(dart.as(_foreign_helper.JS("String", "''+#", this), core.String));
+      throw new core.UnsupportedError('' + this);
     }
     truncate() {
       return this.toInt();
     }
     ceil() {
       return this.ceilToDouble().toInt();
     }
     floor() {
       return this.floorToDouble().toInt();
     }
     round() {
       return this.roundToDouble().toInt();
     }
     ceilToDouble() {
-      return dart.as(_foreign_helper.JS('num', 'Math.ceil(#)', this), core.double);
+      return dart.notNull(Math.ceil(this));
     }
     floorToDouble() {
-      return dart.as(_foreign_helper.JS('num', 'Math.floor(#)', this), core.double);
+      return dart.notNull(Math.floor(this));
     }
     roundToDouble() {
       if (this['<'](0)) {
-        return dart.as(_foreign_helper.JS('num', '-Math.round(-#)', this), core.double);
+        return dart.notNull(-Math.round(-this));
       } else {
-        return dart.as(_foreign_helper.JS('num', 'Math.round(#)', this), core.double);
+        return dart.notNull(Math.round(this));
       }
     }
     truncateToDouble() {
       return this['<'](0) ? this.ceilToDouble() : this.floorToDouble();
     }
     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.dbinary(dart.dinvoke(lowerLimit, 'compareTo', upperLimit), '>', 0)) {
         throw new core.ArgumentError(lowerLimit);
       }
       if (this.compareTo(dart.as(lowerLimit, core.num)) < 0)
         return dart.as(lowerLimit, core.num);
       if (this.compareTo(dart.as(upperLimit, core.num)) > 0)
         return dart.as(upperLimit, core.num);
       return this;
     }
     toDouble() {
       return this;
     }
     toStringAsFixed(fractionDigits) {
       _js_helper.checkInt(fractionDigits);
       if (dart.notNull(fractionDigits < 0) || dart.notNull(fractionDigits > 20)) {
         throw new core.RangeError(fractionDigits);
       }
-      let result = dart.as(_foreign_helper.JS('String', '#.toFixed(#)', this, fractionDigits), core.String);
+      let result = this.toFixed(fractionDigits);
       if (dart.notNull(dart.equals(this, 0)) && dart.notNull(this.isNegative))
         return `-${result}`;
       return result;
     }
     toStringAsExponential(fractionDigits) {
       if (fractionDigits === void 0)
         fractionDigits = null;
       let result = null;
       if (fractionDigits !== null) {
         _js_helper.checkInt(fractionDigits);
         if (dart.notNull(fractionDigits < 0) || dart.notNull(fractionDigits > 20)) {
           throw new core.RangeError(fractionDigits);
         }
-        result = dart.as(_foreign_helper.JS('String', '#.toExponential(#)', this, fractionDigits), core.String);
+        result = this.toExponential(fractionDigits);
       } else {
-        result = dart.as(_foreign_helper.JS('String', '#.toExponential()', this), core.String);
+        result = this.toExponential();
       }
       if (dart.notNull(dart.equals(this, 0)) && dart.notNull(this.isNegative))
         return `-${result}`;
       return result;
     }
     toStringAsPrecision(precision) {
       _js_helper.checkInt(precision);
       if (dart.notNull(precision < 1) || dart.notNull(precision > 21)) {
         throw new core.RangeError(precision);
       }
-      let result = dart.as(_foreign_helper.JS('String', '#.toPrecision(#)', this, precision), core.String);
+      let result = this.toPrecision(precision);
       if (dart.notNull(dart.equals(this, 0)) && dart.notNull(this.isNegative))
         return `-${result}`;
       return result;
     }
     toRadixString(radix) {
       _js_helper.checkInt(radix);
       if (dart.notNull(radix < 2) || dart.notNull(radix > 36))
         throw new core.RangeError(radix);
-      let result = dart.as(_foreign_helper.JS('String', '#.toString(#)', this, radix), core.String);
+      let result = this.toString(radix);
       let rightParenCode = 41;
       if (result.codeUnitAt(result.length - 1) !== rightParenCode) {
         return result;
       }
       return _handleIEtoString(result);
     }
     static _handleIEtoString(result) {
-      let match = _foreign_helper.JS('List|Null', '/^([\\da-z]+)(?:\\.([\\da-z]+))?\\(e\\+(\\d+)\\)$/.exec(#)', result);
+      let match = /^([\da-z]+)(?:\.([\da-z]+))?\(e\+(\d+)\)$/.exec(result);
       if (match === null) {
         throw new core.UnsupportedError(`Unexpected toString result: ${result}`);
       }
-      let result = dart.as(_foreign_helper.JS('String', '#', dart.dindex(match, 1)), core.String);
-      let exponent = dart.as(_foreign_helper.JS("int", "+#", dart.dindex(match, 3)), core.int);
+      let result = dart.dindex(match, 1);
+      let exponent = +dart.dindex(match, 3);
       if (dart.dindex(match, 2) !== null) {
-        result = dart.as(_foreign_helper.JS('String', '# + #', result, dart.dindex(match, 2)), core.String);
-        exponent = dart.as(_foreign_helper.JS('int', '#.length', dart.dindex(match, 2)), core.int);
+        result = result + dart.dindex(match, 2);
+        exponent = dart.dindex(match, 2).length;
       }
       return core.String['+'](result, core.String['*']("0", exponent));
     }
     toString() {
-      if (core.bool['&&'](dart.equals(this, 0), _foreign_helper.JS('bool', '(1 / #) < 0', this))) {
+      if (dart.notNull(dart.equals(this, 0)) && dart.notNull(1 / this < 0)) {
         return '-0.0';
       } else {
-        return dart.as(_foreign_helper.JS('String', '"" + (#)', this), core.String);
+        return "" + this;
       }
     }
     get hashCode() {
-      return dart.as(_foreign_helper.JS('int', '# & 0x1FFFFFFF', this), core.int);
+      return this & 0x1FFFFFFF;
     }
     ['-']() {
-      return dart.as(_foreign_helper.JS('num', '-#', this), core.num);
+      return -this;
     }
     ['+'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      return dart.as(_foreign_helper.JS('num', '# + #', this, other), core.num);
+      return this + other;
     }
     ['-'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      return dart.as(_foreign_helper.JS('num', '# - #', this, other), core.num);
+      return this - other;
     }
     ['/'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      return dart.as(_foreign_helper.JS('num', '# / #', this, other), core.num);
+      return this / other;
     }
     ['*'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      return dart.as(_foreign_helper.JS('num', '# * #', this, other), core.num);
+      return this * other;
     }
     ['%'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      let result = dart.as(_foreign_helper.JS('num', '# % #', this, other), core.num);
+      let result = this % other;
       if (result === 0)
         return 0;
       if (dart.notNull(result) > 0)
         return result;
-      if (dart.dbinary(_foreign_helper.JS('num', '#', other), '<', 0)) {
-        return core.num['-'](result, _foreign_helper.JS('num', '#', other));
+      if (dart.notNull(other) < 0) {
+        return dart.notNull(result) - dart.notNull(other);
       } else {
-        return core.num['+'](result, _foreign_helper.JS('num', '#', other));
+        return dart.notNull(result) + dart.notNull(other);
       }
     }
     _isInt32(value) {
-      return dart.as(_foreign_helper.JS('bool', '(# | 0) === #', value, value), core.bool);
+      return (value | 0) === value;
     }
     ['~/'](other) {
       if (false)
         this._tdivFast(other);
       if (dart.notNull(dart.notNull(dart.notNull(this._isInt32(this)) && dart.notNull(this._isInt32(other))) && dart.notNull(0 !== other)) && dart.notNull(-1 !== other)) {
-        return dart.as(_foreign_helper.JS('int', '(# / #) | 0', this, other), core.int);
+        return this / other | 0;
       } else {
         return this._tdivSlow(other);
       }
     }
     _tdivFast(other) {
-      return dart.as(this._isInt32(this) ? _foreign_helper.JS('int', '(# / #) | 0', this, other) : dart.dinvoke(_foreign_helper.JS('num', '# / #', this, other), 'toInt'), core.int);
+      return this._isInt32(this) ? this / other | 0 : (this / other).toInt();
     }
     _tdivSlow(other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      return dart.as(dart.dinvoke(_foreign_helper.JS('num', '# / #', this, other), 'toInt'), core.int);
+      return (this / other).toInt();
     }
     ['<<'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      if (dart.dbinary(_foreign_helper.JS('num', '#', other), '<', 0))
+      if (dart.notNull(other) < 0)
         throw new core.ArgumentError(other);
       return this._shlPositive(other);
     }
     _shlPositive(other) {
-      return dart.as(_foreign_helper.JS('bool', '# > 31', other) ? 0 : _foreign_helper.JS('JSUInt32', '(# << #) >>> 0', this, other), core.num);
+      return dart.as(other > 31 ? 0 : this << other >>> 0, core.num);
     }
     ['>>'](other) {
       if (false)
         this._shrReceiverPositive(other);
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      if (dart.dbinary(_foreign_helper.JS('num', '#', other), '<', 0))
+      if (dart.notNull(other) < 0)
         throw new core.ArgumentError(other);
       return this._shrOtherPositive(other);
     }
     _shrOtherPositive(other) {
-      return dart.as(dart.dbinary(_foreign_helper.JS('num', '#', this), '>', 0) ? this._shrBothPositive(other) : _foreign_helper.JS('JSUInt32', '(# >> #) >>> 0', this, dart.notNull(other) > 31 ? 31 : other), core.num);
+      return dart.as(dart.notNull(this) > 0 ? this._shrBothPositive(other) : this >> (dart.notNull(other) > 31 ? 31 : other) >>> 0, core.num);
     }
     _shrReceiverPositive(other) {
-      if (dart.dbinary(_foreign_helper.JS('num', '#', other), '<', 0))
+      if (dart.notNull(other) < 0)
         throw new core.ArgumentError(other);
       return this._shrBothPositive(other);
     }
     _shrBothPositive(other) {
-      return dart.as(_foreign_helper.JS('bool', '# > 31', other) ? 0 : _foreign_helper.JS('JSUInt32', '# >>> #', this, other), core.num);
+      return dart.as(other > 31 ? 0 : this >>> other, core.num);
     }
     ['&'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      return dart.as(_foreign_helper.JS('JSUInt32', '(# & #) >>> 0', this, other), core.num);
+      return dart.as((this & other) >>> 0, core.num);
     }
     ['|'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      return dart.as(_foreign_helper.JS('JSUInt32', '(# | #) >>> 0', this, other), core.num);
+      return dart.as((this | other) >>> 0, core.num);
     }
     ['^'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      return dart.as(_foreign_helper.JS('JSUInt32', '(# ^ #) >>> 0', this, other), core.num);
+      return dart.as((this ^ other) >>> 0, core.num);
     }
     ['<'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      return dart.as(_foreign_helper.JS('bool', '# < #', this, other), core.bool);
+      return this < other;
     }
     ['>'](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      return dart.as(_foreign_helper.JS('bool', '# > #', this, other), core.bool);
+      return this > other;
     }
     ['<='](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      return dart.as(_foreign_helper.JS('bool', '# <= #', this, other), core.bool);
+      return this <= other;
     }
     ['>='](other) {
       if (!dart.is(other, core.num))
         throw new core.ArgumentError(other);
-      return dart.as(_foreign_helper.JS('bool', '# >= #', this, other), core.bool);
+      return this >= other;
     }
     get runtimeType() {
       return core.num;
     }
   }
   JSNumber._MIN_INT32 = -2147483648;
   JSNumber._MAX_INT32 = 2147483647;
   class JSInt extends JSNumber {
     JSInt() {
       super.JSNumber();
@@ skipping 21 matching lines @@
     }
     static _bitCount(i) {
       i = dart.as(dart.dbinary(_shru(i, 0), '-', dart.dbinary(_shru(i, 1), '&', 1431655765)), core.int);
       i = dart.notNull((i & 858993459)['+'](dart.dbinary(_shru(i, 2), '&', 858993459)));
       i = 252645135 & dart.notNull(i['+'](_shru(i, 4)));
       i = dart.as(_shru(i, 8), core.int);
       i = dart.as(_shru(i, 16), core.int);
       return i & 63;
     }
     static _shru(value, shift) {
-      return _foreign_helper.JS('int', '# >>> #', value, shift);
+      return value >>> shift;
     }
     static _shrs(value, shift) {
-      return _foreign_helper.JS('int', '# >> #', value, shift);
+      return value >> shift;
     }
     static _ors(a, b) {
-      return _foreign_helper.JS('int', '# | #', a, b);
+      return a | b;
     }
     static _spread(i) {
       i = dart.as(_ors(i, dart.as(_shrs(i, 1), core.int)), core.int);
       i = dart.as(_ors(i, dart.as(_shrs(i, 2), core.int)), core.int);
       i = dart.as(_ors(i, dart.as(_shrs(i, 4), core.int)), core.int);
       i = dart.as(_ors(i, dart.as(_shrs(i, 8), core.int)), core.int);
       i = dart.as(_shru(dart.as(_ors(i, dart.as(_shrs(i, 16), core.int)), core.int), 0), core.int);
       return i;
     }
     get runtimeType() {
       return core.int;
     }
     ['~']() {
-      return dart.as(_foreign_helper.JS('JSUInt32', '(~#) >>> 0', this), core.int);
+      return dart.as(~this >>> 0, core.int);
     }
   }
   class JSDouble extends JSNumber {
     JSDouble() {
       super.JSNumber();
     }
     get runtimeType() {
       return core.double;
     }
   }
   class JSPositiveInt extends JSInt {
   }
   class JSUInt32 extends JSPositiveInt {
   }
   class JSUInt31 extends JSUInt32 {
   }
   class JSString extends Interceptor {
     JSString() {
       super.Interceptor();
     }
     codeUnitAt(index) {
       if (!(typeof index == number))
         throw new core.ArgumentError(index);
       if (index < 0)
         throw new core.RangeError.value(index);
       if (index >= this.length)
         throw new core.RangeError.value(index);
-      return dart.as(_foreign_helper.JS('JSUInt31', '#.charCodeAt(#)', this, index), core.int);
+      return dart.as(this.charCodeAt(index), core.int);
     }
     allMatches(string, start) {
       if (start === void 0)
         start = 0;
       _js_helper.checkString(string);
       _js_helper.checkInt(start);
       if (dart.notNull(0 > start) || dart.notNull(start > string.length)) {
         throw new core.RangeError.range(start, 0, string.length);
       }
       return _js_helper.allMatchesInStringUnchecked(this, string, start);
     }
     matchAsPrefix(string, start) {
       if (start === void 0)
         start = 0;
       if (dart.notNull(start < 0) || dart.notNull(start > string.length)) {
         throw new core.RangeError.range(start, 0, string.length);
       }
       if (start + this.length > string.length)
         return null;
       for (let i = 0; i < this.length; i++) {
         if (string.codeUnitAt(start + i) !== this.codeUnitAt(i)) {
           return null;
         }
       }
       return new _js_helper.StringMatch(start, string, this);
     }
     ['+'](other) {
       if (!(typeof other == string))
         throw new core.ArgumentError(other);
-      return dart.as(_foreign_helper.JS('String', '# + #', this, other), core.String);
+      return this + other;
     }
     endsWith(other) {
       _js_helper.checkString(other);
       let otherLength = other.length;
       if (otherLength > this.length)
         return false;
       return dart.equals(other, this.substring(this.length - otherLength));
     }
     replaceAll(from, to) {
       _js_helper.checkString(to);
@@ skipping 13 matching lines @@
       _js_helper.checkString(to);
       _js_helper.checkInt(startIndex);
       if (dart.notNull(startIndex < 0) || dart.notNull(startIndex > 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) {
       _js_helper.checkNull(pattern);
       if (typeof pattern == string) {
-        return dart.as(_foreign_helper.JS('JSExtendableArray', '#.split(#)', this, pattern), core.List$(core.String));
+        return dart.as(this.split(pattern), core.List$(core.String));
       } else if (dart.notNull(dart.is(pattern, _js_helper.JSSyntaxRegExp)) && dart.notNull(_js_helper.regExpCaptureCount(pattern) === 0)) {
         let re = _js_helper.regExpGetNative(pattern);
-        return dart.as(_foreign_helper.JS('JSExtendableArray', '#.split(#)', this, re), core.List$(core.String));
+        return dart.as(this.split(re), core.List$(core.String));
       } else {
         return this._defaultSplit(pattern);
       }
     }
     _defaultSplit(pattern) {
       let result = new List.from([]);
       let start = 0;
       let length = 1;
       for (let match of pattern.allMatches(this)) {
         let matchStart = dart.as(dart.dload(match, 'start'), core.int);
@@ skipping 17 matching lines @@
       _js_helper.checkInt(index);
       if (dart.notNull(index < 0) || dart.notNull(index > this.length)) {
         throw new core.RangeError.range(index, 0, this.length);
       }
       if (typeof pattern == string) {
         let other = pattern;
         let otherLength = other.length;
         let endIndex = index + otherLength;
         if (endIndex > this.length)
           return false;
-        return dart.equals(other, _foreign_helper.JS('String', '#.substring(#, #)', this, index, endIndex));
+        return dart.equals(other, this.substring(index, endIndex));
       }
       return pattern.matchAsPrefix(this, index) !== null;
     }
     substring(startIndex, endIndex) {
       if (endIndex === void 0)
         endIndex = null;
       _js_helper.checkInt(startIndex);
       if (endIndex === null)
         endIndex = this.length;
       _js_helper.checkInt(endIndex);
       if (startIndex < 0)
         throw new core.RangeError.value(startIndex);
       if (startIndex > endIndex)
         throw new core.RangeError.value(startIndex);
       if (endIndex > this.length)
         throw new core.RangeError.value(endIndex);
-      return dart.as(_foreign_helper.JS('String', '#.substring(#, #)', this, startIndex, endIndex), core.String);
+      return this.substring(startIndex, endIndex);
     }
     toLowerCase() {
-      return dart.as(_foreign_helper.JS('String', '#.toLowerCase()', this), core.String);
+      return this.toLowerCase();
     }
     toUpperCase() {
-      return dart.as(_foreign_helper.JS('String', '#.toUpperCase()', this), core.String);
+      return this.toUpperCase();
     }
     static _isWhitespace(codeUnit) {
       if (codeUnit < 256) {
         switch (codeUnit) {
           case 9:
           case 10:
           case 11:
           case 12:
           case 13:
           case 32:
@@ skipping 48 matching lines @@
         let codeUnit = string.codeUnitAt(index - 1);
         if (dart.notNull(dart.notNull(codeUnit !== SPACE) && dart.notNull(codeUnit !== CARRIAGE_RETURN)) && dart.notNull(!dart.notNull(_isWhitespace(codeUnit)))) {
           break;
         }
         index--;
       }
       return index;
     }
     trim() {
       let NEL = 133;
-      let result = dart.as(_foreign_helper.JS('String', '#.trim()', this), core.String);
+      let result = this.trim();
       if (result.length === 0)
         return result;
       let firstCode = result.codeUnitAt(0);
       let startIndex = 0;
       if (firstCode === NEL) {
         startIndex = _skipLeadingWhitespace(result, 1);
         if (startIndex === result.length)
           return "";
       }
       let endIndex = result.length;
       let lastCode = result.codeUnitAt(endIndex - 1);
       if (lastCode === NEL) {
         endIndex = _skipTrailingWhitespace(result, endIndex - 1);
       }
       if (dart.notNull(startIndex === 0) && dart.notNull(endIndex === result.length))
         return result;
-      return dart.as(_foreign_helper.JS('String', '#.substring(#, #)', result, startIndex, endIndex), core.String);
+      return result.substring(startIndex, endIndex);
     }
     trimLeft() {
       let NEL = 133;
       let result = null;
       let startIndex = 0;
-      if (_foreign_helper.JS('bool', 'typeof #.trimLeft != "undefined"', this)) {
-        result = dart.as(_foreign_helper.JS('String', '#.trimLeft()', this), core.String);
+      if (typeof this.trimLeft != "undefined") {
+        result = this.trimLeft();
         if (result.length === 0)
           return result;
         let firstCode = result.codeUnitAt(0);
         if (firstCode === NEL) {
           startIndex = _skipLeadingWhitespace(result, 1);
         }
       } else {
         result = this;
         startIndex = _skipLeadingWhitespace(this, 0);
       }
       if (startIndex === 0)
         return result;
       if (startIndex === result.length)
         return "";
-      return dart.as(_foreign_helper.JS('String', '#.substring(#)', result, startIndex), core.String);
+      return result.substring(startIndex);
     }
     trimRight() {
       let NEL = 133;
       let result = null;
       let endIndex = null;
-      if (_foreign_helper.JS('bool', 'typeof #.trimRight != "undefined"', this)) {
-        result = dart.as(_foreign_helper.JS('String', '#.trimRight()', this), core.String);
+      if (typeof this.trimRight != "undefined") {
+        result = this.trimRight();
         endIndex = result.length;
         if (endIndex === 0)
           return result;
         let lastCode = result.codeUnitAt(endIndex - 1);
         if (lastCode === NEL) {
           endIndex = _skipTrailingWhitespace(result, endIndex - 1);
         }
       } else {
         result = this;
         endIndex = _skipTrailingWhitespace(this, this.length);
       }
       if (endIndex === result.length)
         return result;
       if (endIndex === 0)
         return "";
-      return dart.as(_foreign_helper.JS('String', '#.substring(#, #)', result, 0, endIndex), core.String);
+      return result.substring(0, endIndex);
     }
     ['*'](times) {
       if (0 >= times)
         return '';
       if (dart.notNull(times === 1) || dart.notNull(this.length === 0))
         return this;
-      if (times !== _foreign_helper.JS('JSUInt32', '# >>> 0', times)) {
+      if (times !== times >>> 0) {
         throw new core.OutOfMemoryError();
       }
       let result = '';
       let s = this;
       while (true) {
         if ((times & 1) === 1)
           result = s['+'](result);
-        times = dart.as(_foreign_helper.JS('JSUInt31', '# >>> 1', times), core.int);
+        times = dart.as(times >>> 1, core.int);
         if (times === 0)
           break;
         s = s;
       }
       return result;
     }
     padLeft(width, padding) {
       if (padding === void 0)
         padding = ' ';
       let delta = width - this.length;
@@ skipping 18 matching lines @@
     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 > this.length)) {
         throw new core.RangeError.range(start, 0, this.length);
       }
       if (typeof pattern == string) {
-        return dart.as(_foreign_helper.JS('int', '#.indexOf(#, #)', this, pattern, start), core.int);
+        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; i <= this.length; i++) {
         if (pattern.matchAsPrefix(this, i) !== null)
           return i;
       }
@@ skipping 34 matching lines @@
     }
     get isEmpty() {
       return this.length === 0;
     }
     get isNotEmpty() {
       return !dart.notNull(this.isEmpty);
     }
     compareTo(other) {
       if (!(typeof other == string))
         throw new core.ArgumentError(other);
-      return dart.equals(this, other) ? 0 : _foreign_helper.JS('bool', '# < #', this, other) ? -1 : 1;
+      return dart.equals(this, other) ? 0 : this < other ? -1 : 1;
     }
     toString() {
       return this;
     }
     get hashCode() {
       let hash = 0;
       for (let i = 0; i < this.length; i++) {
-        hash = 536870911 & dart.notNull(hash['+'](_foreign_helper.JS('int', '#.charCodeAt(#)', this, i)));
+        hash = 536870911 & hash + this.charCodeAt(i);
         hash = 536870911 & hash + ((524287 & hash) << 10);
-        hash = dart.as(_foreign_helper.JS('int', '# ^ (# >> 6)', hash, hash), core.int);
+        hash = hash ^ hash >> 6;
       }
       hash = 536870911 & hash + ((67108863 & hash) << 3);
-      hash = dart.as(_foreign_helper.JS('int', '# ^ (# >> 11)', hash, hash), core.int);
+      hash = hash ^ hash >> 11;
       return 536870911 & hash + ((16383 & hash) << 15);
     }
     get runtimeType() {
       return core.String;
     }
     get length() {
-      return dart.as(_foreign_helper.JS('int', '#.length', this), core.int);
+      return this.length;
     }
     get(index) {
       if (!(typeof index == number))
         throw new core.ArgumentError(index);
       if (dart.notNull(index >= this.length) || dart.notNull(index < 0))
         throw new core.RangeError.value(index);
-      return dart.as(_foreign_helper.JS('String', '#[#]', this, index), core.String);
+      return this[index];
     }
   }
   class _CodeUnits extends _internal.UnmodifiableListBase$(core.int) {
     _CodeUnits(_string) {
       this._string = _string;
       super.UnmodifiableListBase();
     }
     get length() {
       return this._string.length;
     }
@@ skipping 34 matching lines @@
   _interceptors.JSExtendableArray = JSExtendableArray;
   _interceptors.JSExtendableArray$ = JSExtendableArray$;
   _interceptors.JSNumber = JSNumber;
   _interceptors.JSInt = JSInt;
   _interceptors.JSDouble = JSDouble;
   _interceptors.JSPositiveInt = JSPositiveInt;
   _interceptors.JSUInt32 = JSUInt32;
   _interceptors.JSUInt31 = JSUInt31;
   _interceptors.JSString = JSString;
 })(_interceptors || (_interceptors = {}));