Add List.insert.

runtime/lib/array.dart

Index: runtime/lib/array.dart
diff --git a/runtime/lib/array.dart b/runtime/lib/array.dart
index 688cfb5e02380e9ee38e4b5c0a10da678da99c7c..d73ec4c471af854ab5f39c5c8628b3825c691215 100644
--- a/runtime/lib/array.dart
+++ b/runtime/lib/array.dart
@@ -24,6 +24,11 @@ class _ObjectArray<E> implements List<E> {
                             int count)
       native "ObjectArray_copyFromObjectArray";
 
+  void insertAt(int index, E element) {
+    throw new UnsupportedError(
+        "Cannot add to a non-extendable array");
+  }
+
   E removeAt(int index) {
     throw new UnsupportedError(
         "Cannot remove element of a non-extendable array");
@@ -261,6 +266,11 @@ class _ImmutableArray<E> implements List<E> {
 
   int get length native "ObjectArray_getLength";
 
+  void insertAt(int index, E element) {
+    throw new UnsupportedError(
+        "Cannot add to a non-extendable array");

[srdjan, 2013/03/04 00:53:47]

to an immutable array

[Lasse Reichstein Nielsen, 2013/03/04 09:06:02]

Consider changing "immutable" to "unmodifiable" while you are here.

[floitsch, 2013/03/05 17:51:58]

Done.

[floitsch, 2013/03/05 17:51:58]

not in this CL. Filed http://dartbug.com/8925

+  }
+
   E removeAt(int index) {
     throw new UnsupportedError(
         "Cannot modify an immutable array");