Add optional arguments to our indexOf/lastIndexOf methods.

corelib/src/list.dart

 // Copyright (c) 2011, 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.
 
 /**
  * A [List] is an indexable collection with a length. It can be of
  * fixed size or extendable.
  */
 interface List<E> extends Collection<E> factory ListFactory {
 
@@ skipping 58 matching lines @@
    * and return
    *
    *   an integer strictly less than 0 if a < b,
    *   0 if a = b, and
    *   an integer strictly greater than 0 if a > b.
    */
   void sort(int compare(E a, E b));
 
   /**
    * Returns the first index of [element] in this list. Searches this
-   * list from index [startIndex] to the length of the list. Returns
+   * list from index [start] to the length of the list. Returns
    * -1 if [element] is not found.
    */
-  int indexOf(E element, int startIndex);
+  int indexOf(E element, [int start]);
 
   /**
    * Returns the last index of [element] in this list. Searches this
-   * list from index [startIndex] to 0. Returns -1 if [element] is
-   * not found.
+   * list from index [start] (inclusive) to 0. Returns -1 if
+   * [element] is not found.
    */
-  int lastIndexOf(E element, int startIndex);
+  int lastIndexOf(E element, [int start]);
 
   /**
    * Removes all elements in the list. The length of the list
    * becomes zero. Throws an [UnsupportedOperationException] if
    * the list is not extendable.
    */
   void clear();
 
   /**
    * Pops and returns the last element of the list.
@@ skipping 50 matching lines @@
    * not extendable.
    * If [length] is 0, this method does not do anything.
    * If [start] is the length of the array, this method inserts the
    * range at the end of the array.
    * Throws an [IllegalArgumentException] if [length] is negative.
    * Throws an [IndexOutOfRangeException] if [start] or
    * [:start + length:] are out of range.
    */
   void insertRange(int start, int length, [E initialValue]);
 }