Allow Object when doing lookups.

runtime/lib/array.dart

 // 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.
 
 
 // TODO(srdjan): Use shared array implementation.
 class _ObjectArray<E> implements List<E> {
   static final int _classId = (new _ObjectArray(0))._cid;
 
   factory _ObjectArray(length) native "ObjectArray_allocate";
@@ skipping 100 matching lines @@
     int length = end - start;
     if (start == end) return [];
     List list = new _GrowableObjectArray<E>.withCapacity(length);
     list.length = length;
     Arrays.copy(this, start, list, 0, length);
     return list;
   }
 
   // Iterable interface.
 
-  bool contains(E element) {
+  bool contains(Object element) {
     return IterableMixinWorkaround.contains(this, element);
   }
 
   void forEach(f(E element)) {
     IterableMixinWorkaround.forEach(this, f);
   }
 
   String join([String separator = ""]) {
     return IterableMixinWorkaround.joinList(this, separator);
   }
@@ skipping 63 matching lines @@
   }
 
   bool get isNotEmpty => !isEmpty;
 
   Iterable<E> get reversed => IterableMixinWorkaround.reversedList(this);
 
   void sort([int compare(E a, E b)]) {
     IterableMixinWorkaround.sortList(this, compare);
   }
 
-  int indexOf(E element, [int start = 0]) {
+  int indexOf(Object element, [int start = 0]) {
     return Arrays.indexOf(this, element, start, this.length);
   }
 
-  int lastIndexOf(E element, [int start = null]) {
+  int lastIndexOf(Object element, [int start = null]) {
     if (start == null) start = length - 1;
     return Arrays.lastIndexOf(this, element, start);
   }
 
   Iterator<E> get iterator {
     return new _FixedSizeArrayIterator<E>(this);
   }
 
   void add(E element) {
     throw new UnsupportedError(
@@ skipping 144 matching lines @@
     Arrays.copy(this, start, list, 0, length);
     return list;
   }
 
   Iterable<E> getRange(int start, int end) {
     return IterableMixinWorkaround.getRangeList(this, start, end);
   }
 
   // Collection interface.
 
-  bool contains(E element) {
+  bool contains(Object element) {
     return IterableMixinWorkaround.contains(this, element);
   }
 
   void forEach(f(E element)) {
     IterableMixinWorkaround.forEach(this, f);
   }
 
   Iterable map(f(E element)) {
     return IterableMixinWorkaround.mapList(this, f);
   }
@@ skipping 68 matching lines @@
 
   void sort([int compare(E a, E b)]) {
     throw new UnsupportedError(
         "Cannot modify an immutable array");
   }
 
   String toString() {
     return ToString.iterableToString(this);
   }
 
-  int indexOf(E element, [int start = 0]) {
+  int indexOf(Object element, [int start = 0]) {
     return Arrays.indexOf(this, element, start, this.length);
   }
 
-  int lastIndexOf(E element, [int start = null]) {
+  int lastIndexOf(Object element, [int start = null]) {
     if (start == null) start = length - 1;
     return Arrays.lastIndexOf(this, element, start);
   }
 
   Iterator<E> get iterator {
     return new _FixedSizeArrayIterator<E>(this);
   }
 
   void add(E element) {
     throw new UnsupportedError(
@@ skipping 71 matching lines @@
     }
     _position = _length;
     _current = null;
     return false;
   }
 
   E get current {
     return _current;
   }
 }