Hands-On Design Patterns with Kotlin

Type aliases

First, we'll look at how they're declared:

typealias PointsOfDamage = Longtypealias Meters = Int

We use a new keyword here, typealias. From now on, we can use Meters instead of plain old Int to return from our move() method. They aren't new types. The Kotlin compiler will always translate PointsOfDamage to Long during compilation. Using them provides two advantages:

• Better semantics, as in our case. We can tell exactly what the meaning of the value we're returning is.
• One of the main goals of Kotlin is to be concise. Type aliases allow us to hide complex generic expressions. We'll expand on this in the following sections.