Mastering Functional Programming

Either

Either is an effect that is similar to the Try effect that we encountered in the previous chapters.

If you remember, Try is a structure that can contain either of two values—an exception, or the result of the computation. Let's briefly recall our division by zero example from the previous chapters:

def functionalDivision(n1: Double, n2: Double): Try[Double] =  if (n2 == 0) Failure(new RuntimeException("Division by zero!"))  else Success(n1 / n2)

Here, in the case of success, we create a Success data structure. In case of failure, we need to create an exception with a specific error message.

Is it essential to create an exception here? The useful payload is the error message, after all. Exceptions are needed in cases where they are thrown ...