Vladimir Mironov nsk-mironov

Delegated properties is a really nice feature of Kotlin and we are using them a lot in our code base. The entire project contains more than 500 delegated properties. Unfortunatelly, each property compiles to a class with 6 extra methods. While this can be fine if you're running on JVM, this is absolutely unacceptable in case you're targeting Android.

For example, the following class produces 2 more classes, Delegate$bar$1 and Delegate$foo$1:

public class Delegate(private val values: Map<String, Any>) {
  public val bar: String by values
  public val foo: String by values
}

	import com.facebook.litho.Column
	import com.facebook.litho.Component
	import com.facebook.litho.ComponentContext
	import com.facebook.litho.Row
	import com.facebook.litho.fresco.FrescoImage
	import com.facebook.litho.sections.widget.RecyclerCollectionComponent
	import com.facebook.litho.widget.Card
	import com.facebook.litho.widget.CardClip
	import com.facebook.litho.widget.EditText
	import com.facebook.litho.widget.EmptyComponent

	import io.reactivex.Observable
	import io.reactivex.ObservableSource
	import io.reactivex.Observer
	import io.reactivex.internal.fuseable.HasUpstreamObservableSource
	import io.reactivex.internal.fuseable.QueueFuseable
	import io.reactivex.internal.observers.BasicFuseableObserver

	abstract class BaseObservableMap<T : Any, U : Any> protected constructor(private val source: ObservableSource<T>) : Observable<U>(), HasUpstreamObservableSource<T> {
	override fun source(): ObservableSource<T> {
	return source

	class AccountViewModel : ObservableModel by ObservableModelDelegate() {
	@get:Bindable var name by property<CharSequence>("", BR.name)
	@get:Bindable var authenticated by property(false, BR.authenticated)
	@get:Bindable var avatar by property("", BR.avatar)
	}

	final class com/github/vmironov/MainKt$main$first$1 extends kotlin/jvm/internal/FunctionReference implements kotlin/jvm/functions/Function2 {
	// access flags 0x1041
	public synthetic bridge invoke(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
	ALOAD 0
	ALOAD 1
	CHECKCAST com/github/vmironov/A
	ALOAD 2
	CHECKCAST java/lang/Number
	INVOKEVIRTUAL java/lang/Number.intValue ()I
	INVOKEVIRTUAL com/github/vmironov/MainKt$main$first$1.invoke (Lcom/github/vmironov/A;I)I

	package com.github.vmironov

	import kotlin.reflect.jvm.internal.impl.serialization.ClassData
	import kotlin.reflect.jvm.internal.impl.serialization.Flags
	import kotlin.reflect.jvm.internal.impl.serialization.ProtoBuf
	import kotlin.reflect.jvm.internal.impl.serialization.jvm.JvmProtoBufUtil

	data class Foo(val foo: String)
	data class Bar(val bar: String)

	public class StackOverflow {
	public static void main(String[] args) {
	final Observable<Integer> firstObs = Observable.just(1, 2, 3, 4, 5);
	final Observable<Integer> secondObs = Observable.just(2, 4, 6);

	final Observable<Integer> result = secondObs.toList().flatMap(new Func1<List<Integer>, Observable<Integer>>() {
	@Override
	public Observable<Integer> call(final List<Integer> ignore) {
	return firstObs.filter(new Func1<Integer, Boolean>() {
	@Override

	public final class OperatorThrottleList<T> implements Operator<T, List<T>> {
	private final Scheduler scheduler;
	private final long interval;

	public OperatorThrottleList(final long interval, final TimeUnit unit, final Scheduler scheduler) {
	this.interval = unit.toMillis(interval);
	this.scheduler = scheduler;
	}

	@Override

	public class Main {
	public static void main(final String[] args) throws Exception {
	Observable.from(Arrays.asList(0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12))
	.groupBy(item -> item % 4)
	.flatMap(Observable::toList)
	.filter(integers -> integers.size() > 2)
	.toList()
	.subscribe(result -> {
	System.out.printf("%d results %s%n", result.size(), result);
	});