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

sdk/lib/core/list.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.
 
 part of dart.core;
 
 /**
  * An indexable collection of objects with a length.
  *
  * Subclasses of this class implement different kinds of lists.
@@ skipping 100 matching lines @@
     } else {
       result = new List<E>(length);
     }
     for (int i = 0; i < length; i++) {
       result[i] = generator(i);
     }
     return result;
   }
 
   /**
+   * 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.
    */
   E operator [](int index);
 
   /**
    * Sets the value at the given [index] in the list to [value]
    * or throws a [RangeError] if [index] is out of bounds.
    */
   void operator []=(int index, E value);
@@ skipping 316 matching lines @@
    * as values. The `Map.keys` [Iterable] iterates the indices of this list
    * in numerical order.
    *
    *     List<String> words = ['fee', 'fi', 'fo', 'fum'];
    *     Map<int, String> map = words.asMap();
    *     map[0] + map[1];   // 'feefi';
    *     map.keys.toList(); // [0, 1, 2, 3]
    */
   Map<int, E> asMap();
 }