Hands-On Design Patterns with Kotlin

Counting bullets

The game designer catches you in the evening, when you are about to go home of course. He wants to add the ammo count for the entire squad so each squad will be able to report how much ammo it has left:

fun bulletsLeft(): Long {    // Do your job}

Where's the catch?

Well, you see, snipers have ammo as separate bullets:

class Bullet

Riflemen hold their bullets in magazines:

class Magazine(capacity: Int) {    private val bullets = List(capacity) { Bullet() }}

Luckily, you don't have machine gunners on your squad yet, because they carry their ammo in belts...

So, you have a complex structure, which may or may not be nested. And you need to perform a certain operation on this structure as a whole. Here's where the Composite design ...