Revert "Enhance dart:js interop in a backwards compatible manner."

sdk/lib/js/dartium/js_dartium.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Support for interoperating with JavaScript.
  * 
  * This library provides access to JavaScript objects from Dart, allowing
  * Dart code to get and set properties, and call methods of JavaScript objects
  * and invoke JavaScript functions. The library takes care of converting
@@ skipping 71 matching lines @@
  *     var jsMap = new JsObject.jsify({'a': 1, 'b': 2});
  * 
  * This expression creates a JavaScript array:
  *
  *     var jsArray = new JsObject.jsify([1, 2, 3]);
  */
 library dart.js;
 
 import 'dart:collection' show ListMixin;
 import 'dart:nativewrappers';
-import 'dart:math' as math;
-import 'dart:mirrors' as mirrors;
-
-// Pretend we are always in checked mode as we aren't interested in users
-// running Dartium code outside of checked mode.
-final bool CHECK_JS_INVOCATIONS = true;
-
-final _allowedMethods = new Map<Symbol, _DeclarationSet>();
-final _allowedGetters = new Map<Symbol, _DeclarationSet>();
-final _allowedSetters = new Map<Symbol, _DeclarationSet>();
-
-final _jsInterfaceTypes = new Set<Type>();
-Iterable<Type> get jsInterfaceTypes => _jsInterfaceTypes;
-
-/// A collection of methods where all methods have the same name.
-/// This class is intended to optimize whether a specific invocation is
-/// appropritate for at least some of the methods in the collection.
-class _DeclarationSet {
-  _DeclarationSet() : _members = <mirrors.DeclarationMirror>[];
-
-  static bool _checkType(obj, mirrors.TypeMirror type) {
-    if (obj == null) return true;
-    return mirrors.reflectType(obj.runtimeType).isSubtypeOf(type);
-  }
-
-  /// Returns whether the return [value] has a type is consistent with the
-  /// return type from at least one of the members matching the DeclarationSet.
-  bool _checkReturnType(value) {
-    if (value == null) return true;
-    var valueMirror = mirrors.reflectType(value.runtimeType);
-    for (var member in _members) {
-      if (member is mirrors.VariableMirror || member.isGetter) {
-        // TODO(jacobr): actually check return types for getters that return
-        // function types.
-        return true;
-      } else {
-        if (valueMirror.isSubtypeOf(member.returnType)) return true;
-      }
-    }
-    return false;
-  }
-
-  /**
-   * Check whether the [invocation] is consistent with the [member] mirror.
-   */
-  bool _checkDeclaration(
-      Invocation invocation, mirrors.DeclarationMirror member) {
-    if (member is mirrors.VariableMirror || member.isGetter) {
-      // TODO(jacobr): actually check method types against the function type
-      // returned by the getter or field.
-      return true;
-    }
-    var parameters = member.parameters;
-    var positionalArguments = invocation.positionalArguments;
-    // Too many arguments
-    if (parameters.length < positionalArguments.length) return false;
-    // Too few required arguments.
-    if (parameters.length > positionalArguments.length &&
-        !parameters[positionalArguments.length].isOptional) return false;
-    for (var i = 0; i < positionalArguments.length; i++) {
-      if (parameters[i].isNamed) {
-        // Not enough positional arguments.
-        return false;
-      }
-      if (!_checkType(
-          invocation.positionalArguments[i], parameters[i].type)) return false;
-    }
-    if (invocation.namedArguments.isNotEmpty) {
-      var startNamed;
-      for (startNamed = parameters.length - 1; startNamed >= 0; startNamed--) {
-        if (!parameters[startNamed].isNamed) break;
-      }
-      startNamed++;
-
-      // TODO(jacobr): we are unneccessarily using an O(n^2) algorithm here.
-      // If we have JS APIs with a lange number of named parameters we should
-      // optimize this. Either use a HashSet or invert this, walking over
-      // parameters, querying invocation, and making sure we match
-      //invocation.namedArguments.size keys.
-      for (var name in invocation.namedArguments.keys) {
-        bool match = false;
-        for (var j = startNamed; j < parameters.length; j++) {
-          var p = parameters[j];
-          if (p.simpleName == name) {
-            if (!_checkType(invocation.namedArguments[name],
-                parameters[j].type)) return false;
-            match = true;
-            break;
-          }
-        }
-        if (match == false) return false;
-      }
-    }
-    return true;
-  }
-
-  bool checkInvocation(Invocation invocation) {
-    for (var member in _members) {
-      if (_checkDeclaration(invocation, member)) return true;
-    }
-    return false;
-  }
-
-  void add(mirrors.DeclarationMirror mirror) {
-    _members.add(mirror);
-  }
-
-  final List<mirrors.DeclarationMirror> _members;
-}
-
-/**
- * Temporary method that we hope to remove at some point. This method should
- * generally only be called by machine generated code.
- */
-void registerJsInterfaces(List<Type> classes) {
-  if (_finalized == true) {
-    throw 'JSInterop class registration already finalized';
-  }
-  for (Type type in classes) {
-    if (!_jsInterfaceTypes.add(type)) continue; // Already registered.
-    mirrors.ClassMirror typeMirror = mirrors.reflectType(type);
-    typeMirror.declarations.forEach((symbol, declaration) {
-      if (declaration is mirrors.MethodMirror ||
-          declaration is mirrors.VariableMirror && !declaration.isStatic) {
-        bool treatAsGetter = false;
-        bool treatAsSetter = false;
-        if (declaration is mirrors.VariableMirror) {
-          treatAsGetter = true;
-          if (!declaration.isConst && !declaration.isFinal) {
-            treatAsSetter = true;
-          }
-        } else {
-          if (declaration.isGetter) {
-            treatAsGetter = true;
-          } else if (declaration.isSetter) {
-            treatAsSetter = true;
-          } else if (!declaration.isConstructor) {
-            _allowedMethods
-                .putIfAbsent(symbol, () => new _DeclarationSet())
-                .add(declaration);
-          }
-        }
-        if (treatAsGetter) {
-          _allowedGetters
-              .putIfAbsent(symbol, () => new _DeclarationSet())
-              .add(declaration);
-          _allowedMethods
-              .putIfAbsent(symbol, () => new _DeclarationSet())
-              .add(declaration);
-        }
-        if (treatAsSetter) {
-          _allowedSetters
-              .putIfAbsent(symbol, () => new _DeclarationSet())
-              .add(declaration);
-        }
-      }
-    });
-  }
-}
-
-_finalizeJsInterfaces() native "Js_finalizeJsInterfaces";
-
-/**
- * Generates a part file defining source code for JsObjectImpl and related
- * classes. This calass is needed so that type checks for all registered JavaScript
- * interop classes pass.
- */
-String _generateJsObjectImplPart() {
-  Iterable<Type> types = jsInterfaceTypes;
-  var libraryPrefixes = new Map<mirrors.LibraryMirror, String>();
-  var prefixNames = new Set<String>();
-  var sb = new StringBuffer();
-
-  var implements = <String>[];
-  for (var type in types) {
-    mirrors.ClassMirror typeMirror = mirrors.reflectType(type);
-    mirrors.LibraryMirror libraryMirror = typeMirror.owner;
-    var prefixName;
-    if (libraryPrefixes.containsKey(libraryMirror)) {
-      prefixName = libraryPrefixes[libraryMirror];
-    } else {
-      var basePrefixName =
-          mirrors.MirrorSystem.getName(libraryMirror.simpleName);
-      basePrefixName = basePrefixName.replaceAll('.', '_');
-      if (basePrefixName.isEmpty) basePrefixName = "lib";
-      prefixName = basePrefixName;
-      var i = 1;
-      while (prefixNames.contains(prefixName)) {
-        prefixName = '$basePrefixName$i';
-        i++;
-      }
-      prefixNames.add(prefixName);
-      libraryPrefixes[libraryMirror] = prefixName;
-    }
-    implements.add(
-        '${prefixName}.${mirrors.MirrorSystem.getName(typeMirror.simpleName)}');
-  }
-  libraryPrefixes.forEach((libraryMirror, prefix) {
-    sb.writeln('import "${libraryMirror.uri}" as $prefix;');
-  });
-  var implementsClause =
-      implements.isEmpty ? "" : "implements ${implements.join(', ')}";
-  // TODO(jacobr): only certain classes need to be implemented by
-  // Function and Array.
-  sb.write('''
-class JsObjectImpl extends JsObject $implementsClause {
-  JsObjectImpl.internal() : super.internal();
-}
-
-class JsFunctionImpl extends JsFunction $implementsClause {
-  JsFunctionImpl.internal() : super.internal();
-}
-
-class JsArrayImpl<E> extends JsArray<E> $implementsClause {
-  JsArrayImpl.internal() : super.internal();
-}
-''');
-  return sb.toString();
-}
-
-// Start of block of helper methods facilitating emulating JavaScript Array
-// methods on Dart List objects passed to JavaScript via JS interop.
-// TODO(jacobr): match JS more closely.
-String _toStringJs(obj) => '$obj';
-
-// TODO(jacobr): this might not exactly match JS semantics but should be
-// adequate for now.
-int _toIntJs(obj) {
-  if (obj is int) return obj;
-  if (obj is num) return obj.toInt();
-  return num.parse('$obj'.trim(), (_) => 0).toInt();
-}
-
-// TODO(jacobr): this might not exactly match JS semantics but should be
-// adequate for now.
-num _toNumJs(obj) {
-  return obj is num ? obj : num.parse('$obj'.trim(), (_) => 0);
-}
-
-/// Match the behavior of setting List length in JavaScript with the exception
-/// that Dart does not distinguish undefined and null.
-_setListLength(List list, rawlen) {
-  num len = _toNumJs(rawlen);
-  if (len is! int || len < 0) {
-    throw new RangeError("Invalid array length");
-  }
-  if (len > list.length) {
-    _arrayExtend(list, len);
-  } else if (len < list.length) {
-    list.removeRange(len, list.length);
-  }
-  return rawlen;
-}
-
-// TODO(jacobr): should we really bother with this method instead of just
-// shallow copying to a JS array and calling the JavaScript join method?
-String _arrayJoin(List list, sep) {
-  if (sep == null) {
-    sep = ",";
-  }
-  return list.map((e) => e == null ? "" : e.toString()).join(sep.toString());
-}
-
-// TODO(jacobr): should we really bother with this method instead of just
-// shallow copying to a JS array and using the toString method?
-String _arrayToString(List list) => _arrayJoin(list, ",");
-
-int _arrayPush(List list, e) {
-  list.add(e);
-  return list.length;
-}
-
-_arrayPop(List list) {
-  if (list.length > 0) return list.removeLast();
-}
-
-// TODO(jacobr): would it be better to just copy input to a JS List
-// and call Array.concat?
-List _arrayConcat(List input, List args) {
-  var ret = new List.from(input);
-  for (var e in args) {
-    // TODO(jacobr): technically in ES6 we should use
-    // Symbol.isConcatSpreadable to determine whether call addAll. Once v8
-    // supports it, we can make all Dart classes implementing Iterable
-    // specify isConcatSpreadable and tweak this behavior to allow Iterable.
-    if (e is List) {
-      ret.addAll(e);
-    } else {
-      ret.add(e);
-    }
-  }
-  return ret;
-}
-
-List _arraySplice(List input, List args) {
-  int start = 0;
-  if (args.length > 0) {
-    var rawStart = _toIntJs(args[0]);
-    if (rawStart < 0) {
-      start = math.max(0, input.length - rawStart);
-    } else {
-      start = math.min(input.length, rawStart);
-    }
-  }
-  var end = start;
-  if (args.length > 1) {
-    var rawDeleteCount = _toIntJs(args[1]);
-    if (rawDeleteCount < 0) rawDeleteCount = 0;
-    end = math.min(input.length, start + rawDeleteCount);
-  }
-  var replacement = [];
-  var removedElements = input.getRange(start, end).toList();
-  if (args.length > 2) {
-    replacement = args.getRange(2, args.length);
-  }
-  input.replaceRange(start, end, replacement);
-  return removedElements;
-}
-
-List _arrayReverse(List l) {
-  for (var i = 0, j = l.length - 1; i < j; i++, j--) {
-    var tmp = l[i];
-    l[i] = l[j];
-    l[j] = tmp;
-  }
-  return l;
-}
-
-_arrayShift(List l) {
-  if (l.isEmpty) return null; // Technically we should return undefined.
-  return l.removeAt(0);
-}
-
-int _arrayUnshift(List l, List args) {
-  l.insertAll(0, args);
-  return l.length;
-}
-
-_arrayExtend(List l, int newLength) {
-  for (var i = l.length; i < newLength; i++) {
-    // TODO(jacobr): we'd really like to add undefined to better match
-    // JavaScript semantics.
-    l.add(null);
-  }
-}
-
-List _arraySort(List l, rawCompare) {
-  // TODO(jacobr): alternately we could just copy the Array to JavaScript,
-  // invoke the JS sort method and then copy the result back to Dart.
-  Comparator compare;
-  if (rawCompare == null) {
-    compare = (a, b) => _toStringJs(a).compareTo(_toStringJs(b));
-  } else if (rawCompare is JsFunction) {
-    compare = (a, b) => rawCompare.apply([a, b]);
-  } else {
-    compare = rawCompare;
-  }
-  l.sort(compare);
-  return l;
-}
-// End of block of helper methods to emulate JavaScript Array methods on Dart List.
-
-/**
- * Can be called to provide a predictable point where no more JS interfaces can
- * be added. Creating an instance of JsObject will also automatically trigger
- * all JsObjects to be finalized.
- */
-void finalizeJsInterfaces() {
-  if (_finalized == true) {
-    throw 'JSInterop class registration already finalized';
-  }
-  _finalizeJsInterfaces();
-}
 
 JsObject _cachedContext;
 
 JsObject get _context native "Js_context_Callback";
 
-bool get _finalized native "Js_interfacesFinalized_Callback";
-
 JsObject get context {
   if (_cachedContext == null) {
     _cachedContext = _context;
   }
   return _cachedContext;
 }
 
 /**
  * Proxies a JavaScript object to Dart.
  *
  * The properties of the JavaScript object are accessible via the `[]` and
  * `[]=` operators. Methods are callable via [callMethod].
  */
 class JsObject extends NativeFieldWrapperClass2 {
   JsObject.internal();
 
   /**
    * Constructs a new JavaScript object from [constructor] and returns a proxy
    * to it.
    */
-  factory JsObject(JsFunction constructor, [List arguments]) =>
-      _create(constructor, arguments);
+  factory JsObject(JsFunction constructor, [List arguments]) => _create(constructor, arguments);
 
-  static JsObject _create(
-      JsFunction constructor, arguments) native "JsObject_constructorCallback";
-
-  _buildArgs(Invocation invocation) {
-    if (invocation.namedArguments.isEmpty) {
-      return invocation.positionalArguments;
-    } else {
-      var varArgs = new Map<String, Object>();
-      invocation.namedArguments.forEach((symbol, val) {
-        varArgs[mirrors.MirrorSystem.getName(symbol)] = val;
-      });
-      return invocation.positionalArguments.toList()
-        ..add(new JsObject.jsify(varArgs));
-    }
-  }
+  static JsObject _create(JsFunction constructor, arguments) native "JsObject_constructorCallback";
 
   /**
    * Constructs a [JsObject] that proxies a native Dart object; _for expert use
    * only_.
    *
    * Use this constructor only if you wish to get access to JavaScript
    * properties attached to a browser host object, such as a Node or Blob, that
    * is normally automatically converted into a native Dart object.
    * 
    * An exception will be thrown if [object] either is `null` or has the type
    * `bool`, `num`, or `String`.
    */
   factory JsObject.fromBrowserObject(object) {
     if (object is num || object is String || object is bool || object == null) {
-      throw new ArgumentError("object cannot be a num, string, bool, or null");
+      throw new ArgumentError(
+        "object cannot be a num, string, bool, or null");
     }
     return _fromBrowserObject(object);
   }
 
   /**
    * Recursively converts a JSON-like collection of Dart objects to a
    * collection of JavaScript objects and returns a [JsObject] proxy to it.
    *
    * [object] must be a [Map] or [Iterable], the contents of which are also
    * converted. Maps and Iterables are copied to a new JavaScript object.
    * Primitives and other transferrable values are directly converted to their
    * JavaScript type, and all other objects are proxied.
    */
   factory JsObject.jsify(object) {
     if ((object is! Map) && (object is! Iterable)) {
       throw new ArgumentError("object must be a Map or Iterable");
     }
     return _jsify(object);
   }
 
   static JsObject _jsify(object) native "JsObject_jsify";
 
-  static JsObject _fromBrowserObject(
-      object) native "JsObject_fromBrowserObject";
+  static JsObject _fromBrowserObject(object) native "JsObject_fromBrowserObject";
 
   /**
    * Returns the value associated with [property] from the proxied JavaScript
    * object.
    *
    * The type of [property] must be either [String] or [num].
    */
-  operator [](property) native "JsObject_[]";
+  operator[](property) native "JsObject_[]";
 
   /**
    * Sets the value associated with [property] on the proxied JavaScript
    * object.
    *
    * The type of [property] must be either [String] or [num].
    */
-  operator []=(property, value) native "JsObject_[]=";
+  operator[]=(property, value) native "JsObject_[]=";
 
   int get hashCode native "JsObject_hashCode";
 
-  operator ==(other) => other is JsObject && _identityEquality(this, other);
+  operator==(other) => other is JsObject && _identityEquality(this, other);
 
-  static bool _identityEquality(
-      JsObject a, JsObject b) native "JsObject_identityEquality";
+  static bool _identityEquality(JsObject a, JsObject b) native "JsObject_identityEquality";
 
   /**
    * Returns `true` if the JavaScript object contains the specified property
    * either directly or though its prototype chain.
    *
    * This is the equivalent of the `in` operator in JavaScript.
    */
   bool hasProperty(String property) native "JsObject_hasProperty";
 
   /**
    * Removes [property] from the JavaScript object.
    *
    * This is the equivalent of the `delete` operator in JavaScript.
    */
   void deleteProperty(String property) native "JsObject_deleteProperty";
 
   /**
    * Returns `true` if the JavaScript object has [type] in its prototype chain.
    *
    * This is the equivalent of the `instanceof` operator in JavaScript.
    */
   bool instanceof(JsFunction type) native "JsObject_instanceof";
 
   /**
    * Returns the result of the JavaScript objects `toString` method.
    */
   String toString() {
     try {
       return _toString();
-    } catch (e) {
+    } catch(e) {
       return super.toString();
     }
   }
 
   String _toString() native "JsObject_toString";
 
   /**
    * Calls [method] on the JavaScript object with the arguments [args] and
    * returns the result.
    *
    * The type of [method] must be either [String] or [num].
    */
   callMethod(String method, [List args]) {
     try {
       return _callMethod(method, args);
-    } catch (e) {
+    } catch(e) {
       if (hasProperty(method)) {
         rethrow;
       } else {
         throw new NoSuchMethodError(this, new Symbol(method), args, null);
       }
     }
   }
 
-  noSuchMethod(Invocation invocation) {
-    throwError() {
-      throw new NoSuchMethodError(this, invocation.memberName,
-          invocation.positionalArguments, invocation.namedArguments);
-    }
-
-    String name = mirrors.MirrorSystem.getName(invocation.memberName);
-    if (invocation.isGetter) {
-      if (CHECK_JS_INVOCATIONS) {
-        var matches = _allowedGetters[invocation.memberName];
-        if (matches == null &&
-            !_allowedMethods.containsKey(invocation.memberName)) {
-          throwError();
-        }
-        var ret = this[name];
-        if (matches != null && matches._checkReturnType(ret)) return ret;
-        if (ret is Function ||
-            (ret is JsFunction /* shouldn't be needed in the future*/) &&
-                _allowedMethods.containsKey(
-                    invocation.memberName)) return ret; // Warning: we have not bound "this"... we could type check on the Function but that is of little value in Dart.
-        throwError();
-      } else {
-        // TODO(jacobr): should we throw if the JavaScript object doesn't have the property?
-        return this[name];
-      }
-    } else if (invocation.isSetter) {
-      if (CHECK_JS_INVOCATIONS) {
-        var matches = _allowedSetters[invocation.memberName];
-        if (matches == null ||
-            !matches.checkInvocation(invocation)) throwError();
-      }
-      assert(name.endsWith("="));
-      name = name.substring(0, name.length - 1);
-      return this[name] = invocation.positionalArguments.first;
-    } else {
-      // TODO(jacobr): also allow calling getters that look like functions.
-      var matches;
-      if (CHECK_JS_INVOCATIONS) {
-        matches = _allowedMethods[invocation.memberName];
-        if (matches == null ||
-            !matches.checkInvocation(invocation)) throwError();
-      }
-      var ret = this.callMethod(name, _buildArgs(invocation));
-      if (CHECK_JS_INVOCATIONS) {
-        if (!matches._checkReturnType(ret)) throwError();
-      }
-      return ret;
-    }
-  }
-
   _callMethod(String name, List args) native "JsObject_callMethod";
 }
 
 /**
  * Proxies a JavaScript Function object.
  */
-class JsFunction extends JsObject implements Function {
+class JsFunction extends JsObject {
   JsFunction.internal() : super.internal();
 
   /**
    * Returns a [JsFunction] that captures its 'this' binding and calls [f]
    * with the value of this passed as the first argument.
    */
   factory JsFunction.withThis(Function f) => _withThis(f);
 
   /**
    * Invokes the JavaScript function with arguments [args]. If [thisArg] is
    * supplied it is the value of `this` for the invocation.
    */
   dynamic apply(List args, {thisArg}) native "JsFunction_apply";
 
-  noSuchMethod(Invocation invocation) {
-    if (invocation.isMethod && invocation.memberName == #call) {
-      return apply(_buildArgs(invocation));
-    }
-    return super.noSuchMethod(invocation);
-  }
-
   /**
    * Internal only version of apply which uses debugger proxies of Dart objects
    * rather than opaque handles. This method is private because it cannot be
    * efficiently implemented in Dart2Js so should only be used by internal
    * tools.
    */
-  _applyDebuggerOnly(List args,
-      {thisArg}) native "JsFunction_applyDebuggerOnly";
+  _applyDebuggerOnly(List args, {thisArg}) native "JsFunction_applyDebuggerOnly";
 
   static JsFunction _withThis(Function f) native "JsFunction_withThis";
 }
 
 /**
  * A [List] proxying a JavaScript Array.
  */
 class JsArray<E> extends JsObject with ListMixin<E> {
-  JsArray.internal() : super.internal();
 
   factory JsArray() => _newJsArray();
 
   static JsArray _newJsArray() native "JsArray_newJsArray";
 
-  factory JsArray.from(Iterable<E> other) =>
-      _newJsArrayFromSafeList(new List.from(other));
+  factory JsArray.from(Iterable<E> other) => _newJsArrayFromSafeList(new List.from(other));
 
-  static JsArray _newJsArrayFromSafeList(
-      List list) native "JsArray_newJsArrayFromSafeList";
+  static JsArray _newJsArrayFromSafeList(List list) native "JsArray_newJsArrayFromSafeList";
 
   _checkIndex(int index, {bool insert: false}) {
     int length = insert ? this.length + 1 : this.length;
     if (index is int && (index < 0 || index >= length)) {
       throw new RangeError.range(index, 0, length);
     }
   }
 
   _checkRange(int start, int end) {
     int cachedLength = this.length;
     if (start < 0 || start > cachedLength) {
       throw new RangeError.range(start, 0, cachedLength);
     }
     if (end < start || end > cachedLength) {
       throw new RangeError.range(end, start, cachedLength);
     }
   }
 
   // Methods required by ListMixin
 
   E operator [](index) {
     if (index is int) {
       _checkIndex(index);
     }
     return super[index];
   }
 
   void operator []=(index, E value) {
-    if (index is int) {
+    if(index is int) {
       _checkIndex(index);
     }
     super[index] = value;
   }
 
   int get length native "JsArray_length";
 
-  void set length(int length) {
-    super['length'] = length;
-  }
+  void set length(int length) { super['length'] = length; }
 
   // Methods overriden for better performance
 
   void add(E value) {
     callMethod('push', [value]);
   }
 
   void addAll(Iterable<E> iterable) {
     // TODO(jacobr): this can be optimized slightly.
     callMethod('push', new List.from(iterable));
   }
 
   void insert(int index, E element) {
-    _checkIndex(index, insert: true);
+    _checkIndex(index, insert:true);
     callMethod('splice', [index, 0, element]);
   }
 
   E removeAt(int index) {
     _checkIndex(index);
     return callMethod('splice', [index, 1])[0];
   }
 
   E removeLast() {
     if (length == 0) throw new RangeError(-1);
@@ skipping 18 matching lines @@
     callMethod('sort', [compare]);
   }
 }
 
 /**
  * Placeholder object for cases where we need to determine exactly how many
  * args were passed to a function.
  */
 const _UNDEFINED = const Object();
 
-// TODO(jacobr): this method is a hack to work around the lack of proper dart
+// FIXME(jacobr): this method is a hack to work around the lack of proper dart
 // support for varargs methods.
 List _stripUndefinedArgs(List args) =>
     args.takeWhile((i) => i != _UNDEFINED).toList();
 
 /**
  * Returns a method that can be called with an arbitrary number (for n less
  * than 11) of arguments without violating Dart type checks.
  */
 Function _wrapAsDebuggerVarArgsFunction(JsFunction jsFunction) =>
-    ([a1 = _UNDEFINED, a2 = _UNDEFINED, a3 = _UNDEFINED, a4 = _UNDEFINED,
-        a5 = _UNDEFINED, a6 = _UNDEFINED, a7 = _UNDEFINED, a8 = _UNDEFINED,
-        a9 = _UNDEFINED, a10 = _UNDEFINED]) => jsFunction._applyDebuggerOnly(
-            _stripUndefinedArgs([a1, a2, a3, a4, a5, a6, a7, a8, a9, a10]));
+  ([a1=_UNDEFINED, a2=_UNDEFINED, a3=_UNDEFINED, a4=_UNDEFINED,
+    a5=_UNDEFINED, a6=_UNDEFINED, a7=_UNDEFINED, a8=_UNDEFINED,
+    a9=_UNDEFINED, a10=_UNDEFINED]) =>
+    jsFunction._applyDebuggerOnly(_stripUndefinedArgs(
+        [a1,a2,a3,a4,a5,a6,a7,a8,a9,a10]));