Explicitly implementing some DOM iterable APIs for performance

sdk/lib/svg/dartium/svg_dartium.dart

 library dart.dom.svg;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:_collection-dev';
 import 'dart:html';
 import 'dart:html_common';
 import 'dart:nativewrappers';
 // DO NOT EDIT
 // Auto-generated dart:svg library.
@@ skipping 3255 matching lines @@
 
 @DocsEditable
 @DomName('SVGLengthList')
 class LengthList extends NativeFieldWrapperClass1 with ListMixin<Length>, ImmutableListMixin<Length> implements List<Length> {
   LengthList.internal();
 
   @DomName('SVGLengthList.numberOfItems')
   @DocsEditable
   int get numberOfItems native "SVGLengthList_numberOfItems_Getter";
 
-  Length operator[](int index) native "SVGLengthList_item_Callback";
+  Length operator[](int index) {
+    if (index < 0 || index >= length) throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  Length _nativeIndexedGetter(int index) native "SVGLengthList_item_Callback";
 
   void operator[]=(int index, Length value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<Length> mixins.
   // Length is the element type.
 
   // SVG Collections expose numberOfItems rather than length.
   int get length => numberOfItems;
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  Length get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  Length get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  Length 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");
+  }
+
+  Length elementAt(int index) {
+    return this[index];
+  }
+
   // -- end List<Length> mixins.
 
   @DomName('SVGLengthList.appendItem')
   @DocsEditable
   Length appendItem(Length item) native "SVGLengthList_appendItem_Callback";
 
   @DomName('SVGLengthList.clear')
   @DocsEditable
   void clear() native "SVGLengthList_clear_Callback";
 
@@ skipping 503 matching lines @@
 
 @DocsEditable
 @DomName('SVGNumberList')
 class NumberList extends NativeFieldWrapperClass1 with ListMixin<Number>, ImmutableListMixin<Number> implements List<Number> {
   NumberList.internal();
 
   @DomName('SVGNumberList.numberOfItems')
   @DocsEditable
   int get numberOfItems native "SVGNumberList_numberOfItems_Getter";
 
-  Number operator[](int index) native "SVGNumberList_item_Callback";
+  Number operator[](int index) {
+    if (index < 0 || index >= length) throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  Number _nativeIndexedGetter(int index) native "SVGNumberList_item_Callback";
 
   void operator[]=(int index, Number value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<Number> mixins.
   // Number is the element type.
 
   // SVG Collections expose numberOfItems rather than length.
   int get length => numberOfItems;
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  Number get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  Number get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  Number 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");
+  }
+
+  Number elementAt(int index) {
+    return this[index];
+  }
+
   // -- end List<Number> mixins.
 
   @DomName('SVGNumberList.appendItem')
   @DocsEditable
   Number appendItem(Number item) native "SVGNumberList_appendItem_Callback";
 
   @DomName('SVGNumberList.clear')
   @DocsEditable
   void clear() native "SVGNumberList_clear_Callback";
 
@@ skipping 930 matching lines @@
 
 @DocsEditable
 @DomName('SVGPathSegList')
 class PathSegList extends NativeFieldWrapperClass1 with ListMixin<PathSeg>, ImmutableListMixin<PathSeg> implements List<PathSeg> {
   PathSegList.internal();
 
   @DomName('SVGPathSegList.numberOfItems')
   @DocsEditable
   int get numberOfItems native "SVGPathSegList_numberOfItems_Getter";
 
-  PathSeg operator[](int index) native "SVGPathSegList_item_Callback";
+  PathSeg operator[](int index) {
+    if (index < 0 || index >= length) throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  PathSeg _nativeIndexedGetter(int index) native "SVGPathSegList_item_Callback";
 
   void operator[]=(int index, PathSeg value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<PathSeg> mixins.
   // PathSeg is the element type.
 
   // SVG Collections expose numberOfItems rather than length.
   int get length => numberOfItems;
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  PathSeg get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  PathSeg get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  PathSeg 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");
+  }
+
+  PathSeg elementAt(int index) {
+    return this[index];
+  }
+
   // -- end List<PathSeg> mixins.
 
   @DomName('SVGPathSegList.appendItem')
   @DocsEditable
   PathSeg appendItem(PathSeg newItem) native "SVGPathSegList_appendItem_Callback";
 
   @DomName('SVGPathSegList.clear')
   @DocsEditable
   void clear() native "SVGPathSegList_clear_Callback";
 
@@ skipping 784 matching lines @@
 
 @DocsEditable
 @DomName('SVGStringList')
 class StringList extends NativeFieldWrapperClass1 with ListMixin<String>, ImmutableListMixin<String> implements List<String> {
   StringList.internal();
 
   @DomName('SVGStringList.numberOfItems')
   @DocsEditable
   int get numberOfItems native "SVGStringList_numberOfItems_Getter";
 
-  String operator[](int index) native "SVGStringList_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 "SVGStringList_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.
 
   // SVG Collections expose numberOfItems rather than length.
   int get length => numberOfItems;
 
   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) {
+    return this[index];
+  }
+
   // -- end List<String> mixins.
 
   @DomName('SVGStringList.appendItem')
   @DocsEditable
   String appendItem(String item) native "SVGStringList_appendItem_Callback";
 
   @DomName('SVGStringList.clear')
   @DocsEditable
   void clear() native "SVGStringList_clear_Callback";
 
@@ skipping 1049 matching lines @@
 
 @DocsEditable
 @DomName('SVGTransformList')
 class TransformList extends NativeFieldWrapperClass1 with ListMixin<Transform>, ImmutableListMixin<Transform> implements List<Transform> {
   TransformList.internal();
 
   @DomName('SVGTransformList.numberOfItems')
   @DocsEditable
   int get numberOfItems native "SVGTransformList_numberOfItems_Getter";
 
-  Transform operator[](int index) native "SVGTransformList_item_Callback";
+  Transform operator[](int index) {
+    if (index < 0 || index >= length) throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  Transform _nativeIndexedGetter(int index) native "SVGTransformList_item_Callback";
 
   void operator[]=(int index, Transform value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<Transform> mixins.
   // Transform is the element type.
 
   // SVG Collections expose numberOfItems rather than length.
   int get length => numberOfItems;
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  Transform get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  Transform get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  Transform 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");
+  }
+
+  Transform elementAt(int index) {
+    return this[index];
+  }
+
   // -- end List<Transform> mixins.
 
   @DomName('SVGTransformList.appendItem')
   @DocsEditable
   Transform appendItem(Transform item) native "SVGTransformList_appendItem_Callback";
 
   @DomName('SVGTransformList.clear')
   @DocsEditable
   void clear() native "SVGTransformList_clear_Callback";
 
@@ skipping 375 matching lines @@
 
 @DocsEditable
 @DomName('SVGElementInstanceList')
 class _ElementInstanceList extends NativeFieldWrapperClass1 with ListMixin<ElementInstance>, ImmutableListMixin<ElementInstance> implements List<ElementInstance> {
   _ElementInstanceList.internal();
 
   @DomName('SVGElementInstanceList.length')
   @DocsEditable
   int get length native "SVGElementInstanceList_length_Getter";
 
-  ElementInstance operator[](int index) native "SVGElementInstanceList_item_Callback";
+  ElementInstance operator[](int index) {
+    if (index < 0 || index >= length) throw new RangeError.range(index, 0, length);
+    return _nativeIndexedGetter(index);
+  }
+  ElementInstance _nativeIndexedGetter(int index) native "SVGElementInstanceList_item_Callback";
 
   void operator[]=(int index, ElementInstance value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
   }
   // -- start List<ElementInstance> mixins.
   // ElementInstance is the element type.
 
 
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 
+  ElementInstance get first {
+    if (this.length > 0) {
+      return this[0];
+    }
+    throw new StateError("No elements");
+  }
+
+  ElementInstance get last {
+    int len = this.length;
+    if (len > 0) {
+      return this[len - 1];
+    }
+    throw new StateError("No elements");
+  }
+
+  ElementInstance 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");
+  }
+
+  ElementInstance elementAt(int index) {
+    return this[index];
+  }
+
   // -- end List<ElementInstance> mixins.
 
   @DomName('SVGElementInstanceList.item')
   @DocsEditable
   ElementInstance item(int index) native "SVGElementInstanceList_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 327 matching lines @@
 @DocsEditable
 @DomName('SVGVKernElement')
 abstract class _SVGVKernElement extends SvgElement {
   _SVGVKernElement.internal() : super.internal();
 
   @DomName('SVGVKernElement.SVGVKernElement')
   @DocsEditable
   factory _SVGVKernElement() => _SvgElementFactoryProvider.createSvgElement_tag("vkern");
 
 }