scala/scala — pull request #2219 by chuvoks (2013-03-09 11:46:14+00:00)
Title: Optimize RedBlackTree rebalance method by using null optimized list implementation.

rebalance method relies heavily on s.c.i.List. By replacing List with null
optimized version, NList, rebalance operation is significantly more faster.
Test indicate +10 % performance improvement for tree sizes >= 100.