Explicitly implementing some DOM iterable APIs for performance

sdk/lib/html/dartium/html_dartium.dart

 /// The Dart HTML library.
 library dart.dom.html;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:_collection-dev' hide Symbol;
 import 'dart:html_common';
 import 'dart:indexed_db';
 import 'dart:isolate';
 import 'dart:json' as json;
@@ skipping 7229 matching lines @@
 
 @DocsEditable
 @DomName('DOMStringList')
 class DomStringList extends NativeFieldWrapperClass1 with ListMixin<String>, ImmutableListMixin<String> implements List<String> {
   DomStringList.internal();
 
   @DomName('DOMStringList.length')
   @DocsEditable
   int get length native "DOMStringList_length_Getter";
 
-  String operator[](int index) native "DOMStringList_item_Callback";
+  String operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  String _nativeIndexedGetter(int index) native "DOMStringList_item_Callback";
 
   void operator[]=(int index, String value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<String> mixins.
   // String is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  String get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  String get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  String get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  String elementAt(int index) => this[index];
   // -- end List<String> mixins.
 
   @DomName('DOMStringList.contains')
   @DocsEditable
   bool contains(String string) native "DOMStringList_contains_Callback";
 
   @DomName('DOMStringList.item')
   @DocsEditable
   String item(int index) native "DOMStringList_item_Callback";
 
@@ skipping 2487 matching lines @@
 
 @DocsEditable
 @DomName('FileList')
 class FileList extends NativeFieldWrapperClass1 with ListMixin<File>, ImmutableListMixin<File> implements List<File> {
   FileList.internal();
 
   @DomName('FileList.length')
   @DocsEditable
   int get length native "FileList_length_Getter";
 
-  File operator[](int index) native "FileList_item_Callback";
+  File operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  File _nativeIndexedGetter(int index) native "FileList_item_Callback";
 
   void operator[]=(int index, File value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<File> mixins.
   // File is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  File get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  File get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  File get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  File elementAt(int index) => this[index];
   // -- end List<File> mixins.
 
   @DomName('FileList.item')
   @DocsEditable
   File item(int index) native "FileList_item_Callback";
 
 }
 // Copyright (c) 2012, 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.
@@ skipping 813 matching lines @@
 
 @DocsEditable
 @DomName('HTMLAllCollection')
 class HtmlAllCollection extends NativeFieldWrapperClass1 with ListMixin<Node>, ImmutableListMixin<Node> implements List<Node> {
   HtmlAllCollection.internal();
 
   @DomName('HTMLAllCollection.length')
   @DocsEditable
   int get length native "HTMLAllCollection_length_Getter";
 
-  Node operator[](int index) native "HTMLAllCollection_item_Callback";
+  Node operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  Node _nativeIndexedGetter(int index) native "HTMLAllCollection_item_Callback";
 
   void operator[]=(int index, Node value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<Node> mixins.
   // Node is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  Node get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  Node get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  Node get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  Node elementAt(int index) => this[index];
   // -- end List<Node> mixins.
 
   @DomName('HTMLAllCollection.item')
   @DocsEditable
   Node item(int index) native "HTMLAllCollection_item_Callback";
 
   @DomName('HTMLAllCollection.namedItem')
   @DocsEditable
   Node namedItem(String name) native "HTMLAllCollection_namedItem_Callback";
 
@@ skipping 11 matching lines @@
 
 @DocsEditable
 @DomName('HTMLCollection')
 class HtmlCollection extends NativeFieldWrapperClass1 with ListMixin<Node>, ImmutableListMixin<Node> implements List<Node> {
   HtmlCollection.internal();
 
   @DomName('HTMLCollection.length')
   @DocsEditable
   int get length native "HTMLCollection_length_Getter";
 
-  Node operator[](int index) native "HTMLCollection_item_Callback";
+  Node operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  Node _nativeIndexedGetter(int index) native "HTMLCollection_item_Callback";
 
   void operator[]=(int index, Node value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<Node> mixins.
   // Node is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  Node get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  Node get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  Node get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  Node elementAt(int index) => this[index];
   // -- end List<Node> mixins.
 
   @DomName('HTMLCollection.item')
   @DocsEditable
   Node item(int index) native "HTMLCollection_item_Callback";
 
   @DomName('HTMLCollection.namedItem')
   @DocsEditable
   Node namedItem(String name) native "HTMLCollection_namedItem_Callback";
 
@@ skipping 4102 matching lines @@
 
 @DocsEditable
 @DomName('MimeTypeArray')
 class MimeTypeArray extends NativeFieldWrapperClass1 with ListMixin<MimeType>, ImmutableListMixin<MimeType> implements List<MimeType> {
   MimeTypeArray.internal();
 
   @DomName('MimeTypeArray.length')
   @DocsEditable
   int get length native "DOMMimeTypeArray_length_Getter";
 
-  MimeType operator[](int index) native "DOMMimeTypeArray_item_Callback";
+  MimeType operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  MimeType _nativeIndexedGetter(int index) native "DOMMimeTypeArray_item_Callback";
 
   void operator[]=(int index, MimeType value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<MimeType> mixins.
   // MimeType is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  MimeType get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  MimeType get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  MimeType get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  MimeType elementAt(int index) => this[index];
   // -- end List<MimeType> mixins.
 
   @DomName('MimeTypeArray.item')
   @DocsEditable
   MimeType item(int index) native "DOMMimeTypeArray_item_Callback";
 
   @DomName('MimeTypeArray.namedItem')
   @DocsEditable
   MimeType namedItem(String name) native "DOMMimeTypeArray_namedItem_Callback";
 
@@ skipping 1140 matching lines @@
 
 @DocsEditable
 @DomName('NodeList')
 class NodeList extends NativeFieldWrapperClass1 with ListMixin<Node>, ImmutableListMixin<Node> implements List<Node> {
   NodeList.internal();
 
   @DomName('NodeList.length')
   @DocsEditable
   int get length native "NodeList_length_Getter";
 
-  Node operator[](int index) native "NodeList_item_Callback";
+  Node operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  Node _nativeIndexedGetter(int index) native "NodeList_item_Callback";
 
   void operator[]=(int index, Node value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<Node> mixins.
   // Node is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  Node get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  Node get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  Node get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  Node elementAt(int index) => this[index];
   // -- end List<Node> mixins.
 
   @DomName('NodeList.item')
   @DocsEditable
   Node _item(int index) native "NodeList_item_Callback";
 
 }
 // Copyright (c) 2012, 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.
@@ skipping 1104 matching lines @@
 
 @DocsEditable
 @DomName('PluginArray')
 class PluginArray extends NativeFieldWrapperClass1 with ListMixin<Plugin>, ImmutableListMixin<Plugin> implements List<Plugin> {
   PluginArray.internal();
 
   @DomName('PluginArray.length')
   @DocsEditable
   int get length native "DOMPluginArray_length_Getter";
 
-  Plugin operator[](int index) native "DOMPluginArray_item_Callback";
+  Plugin operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  Plugin _nativeIndexedGetter(int index) native "DOMPluginArray_item_Callback";
 
   void operator[]=(int index, Plugin value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<Plugin> mixins.
   // Plugin is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  Plugin get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  Plugin get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  Plugin get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  Plugin elementAt(int index) => this[index];
   // -- end List<Plugin> mixins.
 
   @DomName('PluginArray.item')
   @DocsEditable
   Plugin item(int index) native "DOMPluginArray_item_Callback";
 
   @DomName('PluginArray.namedItem')
   @DocsEditable
   Plugin namedItem(String name) native "DOMPluginArray_namedItem_Callback";
 
@@ skipping 1757 matching lines @@
 
 @DocsEditable
 @DomName('SourceBufferList')
 class SourceBufferList extends EventTarget with ListMixin<SourceBuffer>, ImmutableListMixin<SourceBuffer> implements List<SourceBuffer> {
   SourceBufferList.internal() : super.internal();
 
   @DomName('SourceBufferList.length')
   @DocsEditable
   int get length native "SourceBufferList_length_Getter";
 
-  SourceBuffer operator[](int index) native "SourceBufferList_item_Callback";
+  SourceBuffer operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  SourceBuffer _nativeIndexedGetter(int index) native "SourceBufferList_item_Callback";
 
   void operator[]=(int index, SourceBuffer value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<SourceBuffer> mixins.
   // SourceBuffer is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  SourceBuffer get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  SourceBuffer get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  SourceBuffer get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  SourceBuffer elementAt(int index) => this[index];
   // -- end List<SourceBuffer> mixins.
 
   @DomName('SourceBufferList.addEventListener')
   @DocsEditable
   void $dom_addEventListener(String type, EventListener listener, [bool useCapture]) native "SourceBufferList_addEventListener_Callback";
 
   @DomName('SourceBufferList.dispatchEvent')
   @DocsEditable
   bool dispatchEvent(Event event) native "SourceBufferList_dispatchEvent_Callback";
 
@@ skipping 120 matching lines @@
     return SpeechGrammarList._create_1();
   }
 
   @DocsEditable
   static SpeechGrammarList _create_1() native "SpeechGrammarList__create_1constructorCallback";
 
   @DomName('SpeechGrammarList.length')
   @DocsEditable
   int get length native "SpeechGrammarList_length_Getter";
 
-  SpeechGrammar operator[](int index) native "SpeechGrammarList_item_Callback";
+  SpeechGrammar operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  SpeechGrammar _nativeIndexedGetter(int index) native "SpeechGrammarList_item_Callback";
 
   void operator[]=(int index, SpeechGrammar value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<SpeechGrammar> mixins.
   // SpeechGrammar is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  SpeechGrammar get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  SpeechGrammar get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  SpeechGrammar get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  SpeechGrammar elementAt(int index) => this[index];
   // -- end List<SpeechGrammar> mixins.
 
   void addFromString(String string, [num weight]) {
     if (?weight) {
       _addFromString_1(string, weight);
       return;
     }
     _addFromString_2(string);
     return;
   }
@@ skipping 1674 matching lines @@
 
 @DocsEditable
 @DomName('TextTrackCueList')
 class TextTrackCueList extends NativeFieldWrapperClass1 with ListMixin<TextTrackCue>, ImmutableListMixin<TextTrackCue> implements List<TextTrackCue> {
   TextTrackCueList.internal();
 
   @DomName('TextTrackCueList.length')
   @DocsEditable
   int get length native "TextTrackCueList_length_Getter";
 
-  TextTrackCue operator[](int index) native "TextTrackCueList_item_Callback";
+  TextTrackCue operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  TextTrackCue _nativeIndexedGetter(int index) native "TextTrackCueList_item_Callback";
 
   void operator[]=(int index, TextTrackCue value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<TextTrackCue> mixins.
   // TextTrackCue is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  TextTrackCue get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  TextTrackCue get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  TextTrackCue get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  TextTrackCue elementAt(int index) => this[index];
   // -- end List<TextTrackCue> mixins.
 
   @DomName('TextTrackCueList.getCueById')
   @DocsEditable
   TextTrackCue getCueById(String id) native "TextTrackCueList_getCueById_Callback";
 
   @DomName('TextTrackCueList.item')
   @DocsEditable
   TextTrackCue item(int index) native "TextTrackCueList_item_Callback";
 
@@ skipping 11 matching lines @@
   TextTrackList.internal() : super.internal();
 
   @DomName('TextTrackList.addtrackEvent')
   @DocsEditable
   static const EventStreamProvider<TrackEvent> addTrackEvent = const EventStreamProvider<TrackEvent>('addtrack');
 
   @DomName('TextTrackList.length')
   @DocsEditable
   int get length native "TextTrackList_length_Getter";
 
-  TextTrack operator[](int index) native "TextTrackList_item_Callback";
+  TextTrack operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  TextTrack _nativeIndexedGetter(int index) native "TextTrackList_item_Callback";
 
   void operator[]=(int index, TextTrack value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<TextTrack> mixins.
   // TextTrack is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  TextTrack get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  TextTrack get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  TextTrack get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  TextTrack elementAt(int index) => this[index];
   // -- end List<TextTrack> mixins.
 
   @DomName('TextTrackList.addEventListener')
   @DocsEditable
   void $dom_addEventListener(String type, EventListener listener, [bool useCapture]) native "TextTrackList_addEventListener_Callback";
 
   @DomName('TextTrackList.dispatchEvent')
   @DocsEditable
   bool dispatchEvent(Event evt) native "TextTrackList_dispatchEvent_Callback";
 
@@ skipping 228 matching lines @@
   factory TouchList() => document.$dom_createTouchList();
   TouchList.internal();
 
   /// Checks if this type is supported on the current platform.
   static bool get supported => true;
 
   @DomName('TouchList.length')
   @DocsEditable
   int get length native "TouchList_length_Getter";
 
-  Touch operator[](int index) native "TouchList_item_Callback";
+  Touch operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  Touch _nativeIndexedGetter(int index) native "TouchList_item_Callback";
 
   void operator[]=(int index, Touch value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<Touch> mixins.
   // Touch is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  Touch get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  Touch get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  Touch get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  Touch elementAt(int index) => this[index];
   // -- end List<Touch> mixins.
 
   @DomName('TouchList.item')
   @DocsEditable
   Touch item(int index) native "TouchList_item_Callback";
 
 }
 // Copyright (c) 2012, 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.
@@ skipping 2096 matching lines @@
 
 @DocsEditable
 @DomName('ClientRectList')
 class _ClientRectList extends NativeFieldWrapperClass1 with ListMixin<Rect>, ImmutableListMixin<Rect> implements List<Rect> {
   _ClientRectList.internal();
 
   @DomName('ClientRectList.length')
   @DocsEditable
   int get length native "ClientRectList_length_Getter";
 
-  Rect operator[](int index) native "ClientRectList_item_Callback";
+  Rect operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  Rect _nativeIndexedGetter(int index) native "ClientRectList_item_Callback";
 
   void operator[]=(int index, Rect value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<Rect> mixins.
   // Rect is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  Rect get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  Rect get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  Rect get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  Rect elementAt(int index) => this[index];
   // -- end List<Rect> mixins.
 
   @DomName('ClientRectList.item')
   @DocsEditable
   Rect item(int index) native "ClientRectList_item_Callback";
 
 }
 // Copyright (c) 2012, 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.
@@ skipping 16 matching lines @@
 
 @DocsEditable
 @DomName('CSSRuleList')
 class _CssRuleList extends NativeFieldWrapperClass1 with ListMixin<CssRule>, ImmutableListMixin<CssRule> implements List<CssRule> {
   _CssRuleList.internal();
 
   @DomName('CSSRuleList.length')
   @DocsEditable
   int get length native "CSSRuleList_length_Getter";
 
-  CssRule operator[](int index) native "CSSRuleList_item_Callback";
+  CssRule operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  CssRule _nativeIndexedGetter(int index) native "CSSRuleList_item_Callback";
 
   void operator[]=(int index, CssRule value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<CssRule> mixins.
   // CssRule is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  CssRule get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  CssRule get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  CssRule get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  CssRule elementAt(int index) => this[index];
   // -- end List<CssRule> mixins.
 
   @DomName('CSSRuleList.item')
   @DocsEditable
   CssRule item(int index) native "CSSRuleList_item_Callback";
 
 }
 // Copyright (c) 2012, 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.
 
 // WARNING: Do not edit - generated code.
 
 
 @DocsEditable
 @DomName('CSSValueList')
 class _CssValueList extends _CSSValue with ListMixin<_CSSValue>, ImmutableListMixin<_CSSValue> implements List<_CSSValue> {
   _CssValueList.internal() : super.internal();
 
   @DomName('CSSValueList.length')
   @DocsEditable
   int get length native "CSSValueList_length_Getter";
 
-  _CSSValue operator[](int index) native "CSSValueList_item_Callback";
+  _CSSValue operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  _CSSValue _nativeIndexedGetter(int index) native "CSSValueList_item_Callback";
 
   void operator[]=(int index, _CSSValue value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<_CSSValue> mixins.
   // _CSSValue is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  _CSSValue get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  _CSSValue get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  _CSSValue get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  _CSSValue elementAt(int index) => this[index];
   // -- end List<_CSSValue> mixins.
 
   @DomName('CSSValueList.item')
   @DocsEditable
   _CSSValue item(int index) native "CSSValueList_item_Callback";
 
 }
 // Copyright (c) 2012, 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.
@@ skipping 268 matching lines @@
 
 @DocsEditable
 @DomName('EntryArray')
 class _EntryArray extends NativeFieldWrapperClass1 with ListMixin<Entry>, ImmutableListMixin<Entry> implements List<Entry> {
   _EntryArray.internal();
 
   @DomName('EntryArray.length')
   @DocsEditable
   int get length native "EntryArray_length_Getter";
 
-  Entry operator[](int index) native "EntryArray_item_Callback";
+  Entry operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  Entry _nativeIndexedGetter(int index) native "EntryArray_item_Callback";
 
   void operator[]=(int index, Entry value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<Entry> mixins.
   // Entry is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  Entry get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  Entry get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  Entry get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  Entry elementAt(int index) => this[index];
   // -- end List<Entry> mixins.
 
   @DomName('EntryArray.item')
   @DocsEditable
   Entry item(int index) native "EntryArray_item_Callback";
 
 }
 // Copyright (c) 2012, 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.
 
 // WARNING: Do not edit - generated code.
 
 
 @DocsEditable
 @DomName('EntryArraySync')
 class _EntryArraySync extends NativeFieldWrapperClass1 with ListMixin<_EntrySync>, ImmutableListMixin<_EntrySync> implements List<_EntrySync> {
   _EntryArraySync.internal();
 
   @DomName('EntryArraySync.length')
   @DocsEditable
   int get length native "EntryArraySync_length_Getter";
 
-  _EntrySync operator[](int index) native "EntryArraySync_item_Callback";
+  _EntrySync operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  _EntrySync _nativeIndexedGetter(int index) native "EntryArraySync_item_Callback";
 
   void operator[]=(int index, _EntrySync value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<_EntrySync> mixins.
   // _EntrySync is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  _EntrySync get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  _EntrySync get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  _EntrySync get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  _EntrySync elementAt(int index) => this[index];
   // -- end List<_EntrySync> mixins.
 
   @DomName('EntryArraySync.item')
   @DocsEditable
   _EntrySync item(int index) native "EntryArraySync_item_Callback";
 
 }
 // Copyright (c) 2012, 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.
@@ skipping 64 matching lines @@
 
 @DocsEditable
 @DomName('GamepadList')
 class _GamepadList extends NativeFieldWrapperClass1 with ListMixin<Gamepad>, ImmutableListMixin<Gamepad> implements List<Gamepad> {
   _GamepadList.internal();
 
   @DomName('GamepadList.length')
   @DocsEditable
   int get length native "GamepadList_length_Getter";
 
-  Gamepad operator[](int index) native "GamepadList_item_Callback";
+  Gamepad operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  Gamepad _nativeIndexedGetter(int index) native "GamepadList_item_Callback";
 
   void operator[]=(int index, Gamepad value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<Gamepad> mixins.
   // Gamepad is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  Gamepad get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  Gamepad get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  Gamepad get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  Gamepad elementAt(int index) => this[index];
   // -- end List<Gamepad> mixins.
 
   @DomName('GamepadList.item')
   @DocsEditable
   Gamepad item(int index) native "GamepadList_item_Callback";
 
 }
 // Copyright (c) 2012, 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.
@@ skipping 94 matching lines @@
 
 @DocsEditable
 @DomName('NamedNodeMap')
 class _NamedNodeMap extends NativeFieldWrapperClass1 with ListMixin<Node>, ImmutableListMixin<Node> implements List<Node> {
   _NamedNodeMap.internal();
 
   @DomName('NamedNodeMap.length')
   @DocsEditable
   int get length native "NamedNodeMap_length_Getter";
 
-  Node operator[](int index) native "NamedNodeMap_item_Callback";
+  Node operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  Node _nativeIndexedGetter(int index) native "NamedNodeMap_item_Callback";
 
   void operator[]=(int index, Node value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<Node> mixins.
   // Node is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  Node get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  Node get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  Node get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  Node elementAt(int index) => this[index];
   // -- end List<Node> mixins.
 
   @DomName('NamedNodeMap.getNamedItem')
   @DocsEditable
   Node getNamedItem(String name) native "NamedNodeMap_getNamedItem_Callback";
 
   @DomName('NamedNodeMap.getNamedItemNS')
   @DocsEditable
   Node getNamedItemNS(String namespaceURI, String localName) native "NamedNodeMap_getNamedItemNS_Callback";
 
@@ skipping 111 matching lines @@
 
 @DocsEditable
 @DomName('SpeechInputResultList')
 class _SpeechInputResultList extends NativeFieldWrapperClass1 with ListMixin<SpeechInputResult>, ImmutableListMixin<SpeechInputResult> implements List<SpeechInputResult> {
   _SpeechInputResultList.internal();
 
   @DomName('SpeechInputResultList.length')
   @DocsEditable
   int get length native "SpeechInputResultList_length_Getter";
 
-  SpeechInputResult operator[](int index) native "SpeechInputResultList_item_Callback";
+  SpeechInputResult operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  SpeechInputResult _nativeIndexedGetter(int index) native "SpeechInputResultList_item_Callback";
 
   void operator[]=(int index, SpeechInputResult value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<SpeechInputResult> mixins.
   // SpeechInputResult is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  SpeechInputResult get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  SpeechInputResult get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  SpeechInputResult get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  SpeechInputResult elementAt(int index) => this[index];
   // -- end List<SpeechInputResult> mixins.
 
   @DomName('SpeechInputResultList.item')
   @DocsEditable
   SpeechInputResult item(int index) native "SpeechInputResultList_item_Callback";
 
 }
 // Copyright (c) 2012, 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.
 
 // WARNING: Do not edit - generated code.
 
 
 @DocsEditable
 @DomName('SpeechRecognitionResultList')
 class _SpeechRecognitionResultList extends NativeFieldWrapperClass1 with ListMixin<SpeechRecognitionResult>, ImmutableListMixin<SpeechRecognitionResult> implements List<SpeechRecognitionResult> {
   _SpeechRecognitionResultList.internal();
 
   @DomName('SpeechRecognitionResultList.length')
   @DocsEditable
   int get length native "SpeechRecognitionResultList_length_Getter";
 
-  SpeechRecognitionResult operator[](int index) native "SpeechRecognitionResultList_item_Callback";
+  SpeechRecognitionResult operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  SpeechRecognitionResult _nativeIndexedGetter(int index) native "SpeechRecognitionResultList_item_Callback";
 
   void operator[]=(int index, SpeechRecognitionResult value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<SpeechRecognitionResult> mixins.
   // SpeechRecognitionResult is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  SpeechRecognitionResult get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  SpeechRecognitionResult get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  SpeechRecognitionResult get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  SpeechRecognitionResult elementAt(int index) => this[index];
   // -- end List<SpeechRecognitionResult> mixins.
 
   @DomName('SpeechRecognitionResultList.item')
   @DocsEditable
   SpeechRecognitionResult item(int index) native "SpeechRecognitionResultList_item_Callback";
 
 }
 // Copyright (c) 2012, 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.
 
 // WARNING: Do not edit - generated code.
 
 
 @DocsEditable
 @DomName('StyleSheetList')
 class _StyleSheetList extends NativeFieldWrapperClass1 with ListMixin<StyleSheet>, ImmutableListMixin<StyleSheet> implements List<StyleSheet> {
   _StyleSheetList.internal();
 
   @DomName('StyleSheetList.length')
   @DocsEditable
   int get length native "StyleSheetList_length_Getter";
 
-  StyleSheet operator[](int index) native "StyleSheetList_item_Callback";
+  StyleSheet operator[](int index) {
+    if (index < 0 || index >= length)
+      throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  StyleSheet _nativeIndexedGetter(int index) native "StyleSheetList_item_Callback";
 
   void operator[]=(int index, StyleSheet value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<StyleSheet> mixins.
   // StyleSheet is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  StyleSheet get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  StyleSheet get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  StyleSheet get single {
+    int len = this.length;
+    if (len == 1) {
+      return this[0];
+    }
+    if (len == 0) throw new StateError("No elements");
+    throw new StateError("More than one element");
+  }
+
+  StyleSheet elementAt(int index) => this[index];
   // -- end List<StyleSheet> mixins.
 
   @DomName('StyleSheetList.item')
   @DocsEditable
   StyleSheet item(int index) native "StyleSheetList_item_Callback";
 
 }
 // Copyright (c) 2012, 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.
@@ skipping 4576 matching lines @@
   }
 
   _send(msg) {
     _sendToHelperIsolate(msg, _sendPort);
   }
 }
 
 get _pureIsolateTimerFactoryClosure =>
     ((int milliSeconds, void callback(Timer time), bool repeating) =>
         new _PureIsolateTimer(milliSeconds, callback, repeating));