To test class mutation in Swift. The same behaviour as Kotlin, when the class has mutable properties

Mutation.swift

//: [Previous](@previous)

/*:
 # Mutation

 To test class mutation in Swift.

 The same behaviour as Kotlin, when the class has mutable properties.
 */

import Foundation
import simd

class Node {
    var position = float3(0)
    var orientation = float4(0)
    var name: String = ""
    var children: [Node] = []

    init(name: String) {
        self.name = name
    }
}

let transform: (Node) -> () = {
    $0.children.forEach {
        let timestamp = Date().timeIntervalSinceReferenceDate
        $0.name = "\(timestamp)"
        $0.position = float3(1.0, 1.0, Float.random(in: Range<Float>(uncheckedBounds: (lower: 1.0, upper: 10.0))))
        $0.orientation = simd_quatf(angle: .pi / 4, axis: float3(0.0, 0.0, Float.random(in: Range<Float>(uncheckedBounds: (lower: 1.0, upper: 10.0))))).vector
    }
}

let left = Node(name: "left")
let nodeA = Node(name: "A")
let nodeB = Node(name: "B")
left.children = [nodeA, nodeB]

let right = Node(name: "right")
right.children = [nodeA, nodeB]

let leftTree = [left, right]
let rightTree = leftTree.reversed()

let printNode: (Node) -> () = {
    print("parent: \($0.name)")

    $0.children.forEach {
        print("child is \($0.name)")
        print("position: \($0.position)")
        print("orientation: \($0.orientation)")
    }
}

print("left tree")
leftTree.forEach(printNode)

print("""
===========================

Start Mutation

===========================
""")

print("right tree")

rightTree.forEach(transform)

let nodeC = nodeA
nodeC.name = "C"
nodeC.position = float3(5.0, 5.0, 5.0)

print("node A \(nodeA.name), position: \(nodeA.position)")

rightTree.forEach(printNode)

print("""
===========================

Result

===========================
""")

print("left tree")
leftTree.forEach(printNode)

print("light tree")
rightTree.forEach(printNode)

//: [Next](@next)