Scala Programming Projects

Summary

In this chapter, we saw how we can handle optional values and how to handle errors in a purely functional way. You are now better equipped to write safer programs that do not throw exceptions and crash unexpectedly.

If you use Java libraries or some non-purely-functional Scala libraries, you will notice that they can throw exceptions. If you do not want your program to crash when exceptions are raised, I advise you to wrap them as early as possible inside Either or Validated.

We saw how Either can be used to handle errors sequentially, and how Validated can handle errors in parallel. As these two types are very similar, I would advise you to use Validated most of the time. Instances of Validated can indeed handle errors in parallel ...