Parallel collections

Well, before discussing parallel collections in Scala, it's important to have some insight about what parallel computation is. How's it different from concurrent and asynchronous?

Well, we have spent some time understanding that asynchronous computation is non-blocking, hence we know that async computation happens from outside of the main program flow and gives you the value once the computation gets completed. To understand the difference between concurrent and parallel computation, let's look at the following example:

In the example, we are given a collection of numbers where we want to apply a function to each element of the collection to get a new collection. One method is to take a value out from the starting collection, add one to it, and put that value in a new collection, until the first collection is empty. Now, this process can be made faster by introducing two threads to perform the task of adding one to an element of the collection; let's put it another way...