angle.scala

// Alternative to sealed abstract case class pattern for Scala 2.12.2+
// Benefits:
//  - 1 final class instead of 1 sealed class + anonymous subclass
//  - portable to Scala 3 regardless of opaque types
//  - less boilerplate

final case class Angle private (toDegrees: Int) {
  // Define our own `copy` method to suppress synthetic one
  // Add private to prevent it from being used
  def copy(degrees: Int = toDegrees): Angle = Angle.fromDegrees(degrees)
}

object Angle {
  // Define our own `apply` method to suppress synthetic one
  // Can keep this public if you want Angle(-32) to work
  private def apply(n: Int): Angle = new Angle(((n % 360) + 360) % 360)
  def fromDegrees(n: Int): Angle = apply(n)
}