Scala Partial Functions

Resources

• Partial Functions | Advanced Scala and Functional Programming

Basics

From this lecture.

trait PartialFunction[-A, +B] extends (A => B) {
  def apply(x: A): B
  def isDefinedAt(x: A): Boolean
}

// how to use

val simplePF: PartialFunction[Int, Int] = {
  case 1 => 42
  case 2 => 65
  case 3 => 999
}