Add Iterable.range, List.range and int.to.

sdk/lib/core/list.dart

Index: sdk/lib/core/list.dart
diff --git a/sdk/lib/core/list.dart b/sdk/lib/core/list.dart
index 997b2c3f31ad09afcfa93a96a6975b1857ae5cfc..82e60a16930abc3dcc9cddcf5e18082f03a055a4 100644
--- a/sdk/lib/core/list.dart
+++ b/sdk/lib/core/list.dart
@@ -118,6 +118,38 @@ abstract class List<E> implements Iterable<E>, EfficientLength {
   }
 
   /**
+   * Create a list of values between `from` and `to`.
+   *
+   * The list starts with `from` as the first value, and then
+   * progresses towards `to` in increments of `step`, and stops when reaching
+   * or overshooting `to`. If it hits `to` the `to` value is included,
+   * otherwise it isn't.
+   *
+   * If `to` is less than `from`, the values are in decreasing order.
+   *
+   * The [step] value must always be positive. It defaults to `1`.
+   *
+   * If [growable] is true, the resulting list is growable, otherwise
+   * it defaults to a fixed-length list.
+   */
+  static List<int> range(int from, int to, {int step: 1, growable: false}) {
+    if (step <= 0) {
+      throw new RangeError.value("Step must be positive, was $step");
+    }
+    final int delta = to - from;
+    if (delta < 0) {
+      step = -step;
+    }
+    final int steps = delta ~/ step + 1;
+    List list = growable ? new List<int>()..length = steps
+                         : new List<int>(steps);
+    for (int i = 0; i < steps; i++) {
+      list[i] = from + i * step;
+    }
+    return list;
+  }
+
+  /**
    * Returns the object at the given [index] in the list
    * or throws a [RangeError] if [index] is out of bounds.
    */