Scala match expression as a switch statment

Question

I am trying to use a scala match expression as a switch statement. I do not have my case values stored in an array and want to generate it during runtime.

while (completedTasks < todoTasks) {
      // Submit if machine 0 is ready.

      if (status(0) == READY)
        submit(0, 1)

      // Submit if machine 0 is failed.
      if (status(0) == FAILED)
        submit(0, 1)
}

How can I convert the above piece of code into a match expression. I am trying to replicate a cloud server and run multiple threads to avoid communication overhead. Assumen having 10 machine.

Answer 1

You can use pattern matching on the ADT Structure.

Here is one of the ways how you can do your example:

sealed trait Status
case object Ready extends Status
case object Failed extends Status

//Some logic to output READY or FALSE here.
// For example purposes we always return READY.
def status(value: Int): Status = Ready 
                               
status(0) match {
  case Ready => "I'm ready"
  case Failed => "I'm failed"
}

You can try out this example in a playground here.