Updates on files

Author: Alexander Rogalskiy

patterns/src/main/kotlin/io/nullables/api/playground/patterns/delegation2/Engine.kt

@@ -0,0 +1,18 @@
+package io.nullables.api.playground.patterns.delegation2
+
+interface Engine {
+    fun printEngine()
+}
+
+class Diesel(val power: Int) : Engine {
+    override fun printEngine() {
+        println("Diesel $power")
+    }
+}
+
+class Car(e: Engine) : Engine by e
+
+fun main(args: Array<String>) {
+    val engine = Diesel(10)
+    Car(engine).printEngine()
+}

patterns/src/main/kotlin/io/nullables/api/playground/patterns/delegation3/EngineDelegate.java

@@ -0,0 +1,56 @@
+package io.nullables.api.playground.patterns.delegation3;
+
+import kotlin.lazy
+import kotlin.properties.Delegates
+import kotlin.reflect.KProperty
+
+class EngineDelegate {
+    private val speedLimit : Int = 5
+
+    operator fun getValue(thisRef: Any?, property: KProperty<*>): String {
+        return if (thisRef is HybridCar && thisRef.speed < speedLimit) "Electric" else "Gas"
+    }
+
+    operator fun setValue(thisRef: Any?, property: KProperty<*>, value: String) {
+        println("$value has been manually set to '${property.name}' in $thisRef.")
+    }
+}
+
+class HybridCar(var speed : Int) {
+    var engine: String by EngineDelegate()
+}
+
+class LazyCar {
+    val engine: String by lazy {
+        println("computed!")
+        "Gas"
+    }
+}
+
+class SmartCar {
+    var speed : Int by Delegates.observable(10, {
+        prop, old, new -> println("Changed from $old to $new")
+    })
+}
+
+class SerializedCar (val map: Map<String, Any?>) {
+    val speed : Int by map
+    val engine : String by map
+}
+
+fun main(args: Array<String>) {
+    val car = HybridCar(10)
+    println(car.engine) // output: Gas
+    car.speed = 2
+    println(car.engine) // output: Electric
+
+    val smartCar = SmartCar()
+    smartCar.speed = 10;
+    smartCar.speed++
+
+    val map = HashMap<String, Any?>()
+    map.put("speed", 10)
+    map.put("engine", "Gas")
+    var serializedCar = SerializedCar(map)
+    println("Car with engine ${serializedCar.engine} and speed ${serializedCar.speed}")
+}

patterns/src/main/kotlin/io/nullables/api/playground/patterns/extension/Office.kt

@@ -0,0 +1,14 @@
+package io.nullables.api.playground.patterns.extension
+
+open class Office(var space : Int)
+
+fun Office.hasTable() = true
+
+fun Office.plus(right : Office) : Office {
+    return Office(this.space + right.space)
+}
+
+fun main(args: Array<String>) {
+    val myOffice = Office(1)
+    println("Office has table ${myOffice.hasTable()}") // output: Office has table yes
+}