Functional Programming: A PragPub Anthology

Using Parallel Collections

We want our applications to be responsive and faster, but we don’t want to compromise their correctness. The purity of functional programming is our ally in this area. When we set out to make code concurrent, we must ensure the purity of operations, making sure they don’t have side effects. This means using vals (rather than vars) and immutable objects. For avoiding side effects, Scala rewards us with faster response without compromising the correctness of the results.

Let’s first create a utility function that will allow us to measure the time operations will take. This will help us compare the sequential processing and its concurrent counterpart.

object Time {
  def code(block: () => Unit) = {
    val ...