title: What is the fastest way to sum a collection in Scala
body: <p>I've tried different collections in Scala to sum it's elements and they are much slower than Java sums it's arrays (with <code>for</code> cycle). Is there a way for Scala to be as fast as Java arrays? </p>
  
  <p>I've heard that in scala 2.8 arrays will be same as in java, but they are much slower in practice</p>