Added nextIntRange to dartvm and dart2js.

runtime/lib/math_patch.dart

Index: runtime/lib/math_patch.dart
diff --git a/runtime/lib/math_patch.dart b/runtime/lib/math_patch.dart
index 0612d3db2ff7731f55241be980faac219b1b3497..e407633e4f360815e4a55920d984bcacf5b92704 100644
--- a/runtime/lib/math_patch.dart
+++ b/runtime/lib/math_patch.dart
@@ -68,6 +68,15 @@ class _Random implements Random {
     return result;
   }
 
+int nextIntRange(int min, int max) {
+    int range = max - min;
+    if (range <= 0) {

[floitsch, 2013/11/18 13:36:03]

Doesn't test if max or min is negative.

+      throw new ArgumentError("min is greater then or equal to max");

[floitsch, 2013/11/18 13:36:03]

Would be nice to have the values in the error message.

+    }
+    range = nextInt(range);

[floitsch, 2013/11/18 13:36:03]

I wouldn't have called the result of the random-call "range".

Either use a different variable, or just "return min + nextInt(range);".

+    return min + range;
+  }
+
   double nextDouble() {
     return ((nextInt(1 << 26) << 27) + nextInt(1 << 27)) / _POW2_53_D;
   }