Node mutation. Testing how a class is being mutated on Kotlin.

Mutation.kt

/**
 * You can edit, run, and share this code. 
 * play.kotlinlang.org 
 */

class Node(name: String) {
    var position: FloatArray = floatArrayOf(0.0f, 0.0f, 0.0f)
    var rotation: FloatArray = floatArrayOf(0.0f, 0.0f, 0.0f, 0.0f)
    var name: String = name
    var children: Array<Node> = emptyArray()    
}

fun main() {
    val left = Node(name = "left")
    val nodeA = Node(name = "A")
    val nodeB = Node(name = "B")

    left.children = arrayOf(nodeA, nodeB)
    
    val right = Node(name = "right")
    right.children = arrayOf(nodeA, nodeB)

    val leftTree = arrayOf(left, right)
    
    val rightTree = arrayOf(right, left)
    
    val printNode = { it: Node -> 
        println("parent: ${it.name}")
        
        it.children.forEach {
            println("child is ${it.name}")
            println("position: ${it.position[0]}, ${it.position[1]}, ${it.position[2]}")
            println("rotation: ${it.rotation[0]}, ${it.rotation[1]}, ${it.rotation[2]}, ${it.rotation[3]}")
        }
    }
    
    println("left tree:")
    leftTree.forEach(printNode)
    
    println("===============")
    println("Start mutating:")
    println("===============")
    
    val transform = { it: Node ->
        it.children.forEachIndexed { index, child ->
            child.name = "$index"
            child.position = floatArrayOf(1.0f, 1.0f, 1.0f + index)
            child.rotation = floatArrayOf(1.0f, 1.0f, 1.0f, 0.7f + index)
        }
    }

    println("right tree:")
    rightTree.forEach(transform)
    
    val nodeC = nodeA
    nodeC.name = "C"
    println("node A: ${nodeA.name}")
    
    rightTree.forEach(printNode)
    
    println("===============")
    println("Result:")
    println("===============")
    
    println("left tree:")
    leftTree.forEach(printNode)
    
    println("right tree:")
    rightTree.forEach(printNode)
}