happy-bracket

interface Traced<E, S : Trace.Stage> {
    val trace: Trace<E, S>
}

data class EffectTracer<E : Traced<E, Trace.Stage.Out>, M : Traced<E, Trace.Stage.In>> internal constructor(
    private val state: State,
    private val factory: (Trace<E, Trace.Stage.Out>) -> E
) {

    fun launch(): Pair<EffectTracer<E, M>, Set<E>> {

happy-bracket

sealed class HList {
    object HNil : HList()
    data class HNode<V, T : HList>(val value: V, val next: T) : HList()
    data class HPlus<H1 : HList, H2 : HList>(val h1: H1, val h2: H2) : HList() // note this!
}

happy-bracket

fun main() {

    mock<WriteRound<Int, WriteRound<String, WriteRound<Boolean, Terminate>>>>()
        .set(3)
        .set("sss")
        .set(true)

}

fun <T> mock(): T = TODO()

happy-bracket

val src: List<Single<Unit>> = ...
fun sink(result: Single<Unit>) { ... }

src.map { it.toObservable().k() }
  .sequence(ObservableK.applicative()).fix()
  .map { Unit }
  .observable
  .firstElement()
  .also(::sink)

happy-bracket

fun main() {
    
    val result = Free.fx<ForStore, String> { 
        put("arrow", "huita").bind()
        update<String>("arrow") { "let's me do this" }.bind()
        val arrow = get<String>("arrow").bind()
        put("arrow-huita", "I have spoken").bind()
        delete("arrow-huita")
        arrow ?: ""
    }

happy-bracket

sealed class HList<T>

object HNil : HList<Nothing>()

data class HNode<T, H : HList<*>>(
    val value: T,
    val next: H
) : HList<H>()

infix fun <A, B> A.hcons(b: B): HNode<B, HNode<A, HNil>> =

happy-bracket

class Lateinit<T> {

    private var value: T? = null
    private var dependants = mutableListOf<Dependant<T, *>>()

    operator fun getValue(thisRef: Any?, kprop: KProperty<*>): T =
        value ?: throw Exception()

    operator fun setValue(thisRef: Any?, kprop: KProperty<*>, v: T) {
        value = v

happy-bracket

{-# LANGUAGE GADTs #-}
module Main where

newtype Login = Login String
newtype Password = Password String

data LoginState = Auth {
  login :: Login,
  password :: Password
} | Nop

happy-bracket

sealed class Either2<A, B> {

    data class Op1<A>(val value: A) : Either2<A, Nothing>()
    data class Op2<B>(val value: B) : Either2<Nothing, B>()

}

sealed class Either3<A, B, C> : Either2<A, B>() {
    

happy-bracket

data class ChatState(
  val messages: List<Message> = emptyList(),
  val input: String = ""
)

sealed class ChatMutation {
  data class NewMessage(val message: Message) : ChatMutation()
  data class NewInput(val input: String) : ChatMutation()
  object SendMessage : ChatMutation()
}