小编zer*_*ing的帖子

Homo意味着Haskell中的等同和同态是关于保留结构.

例如,fmap类别仿函数的函数保留了结构.

但同态是什么意思呢？

我正在尝试了解Product和Coproduct对应于以下图片：

产品：

副产品：

据我了解，ProductHaskell中的类型例如：

data Pair = P Int Double

和Sum类型是：

data Pair = I Int | D Double 

如何理解Sum与Product类型有关的图像？

图片来自http://blog.higher-order.com/blog/2014/03/19/monoid-morphisms-products-coproducts/。

我有一个 Actor，每 2 秒产生一个NotUsed. 也许它没有任何意义，但仅用于测试目的。

import akka.NotUsed
import akka.actor.{Actor, ActorLogging, Props}
import akka.stream.{ActorMaterializer, KillSwitches}
import akka.stream.scaladsl.{Keep, Sink, Source}
import com.sweetsoft.FsmSystem.{Add, StartTicker, StopTicker}

import scala.concurrent.duration._

object AddActor {

  def props: Props = Props(new AddActor)

}

final class AddActor extends Actor with ActorLogging {

  implicit val materilizer = ActorMaterializer()

  private val consumer: NotUsed => Unit = _ =>
    context.parent ! Add

  private val runnable = Source.tick(2.second, 2.second, NotUsed)
    .named("Ticker")
    .toMat(Sink.foreach(consumer))(Keep.both)

  override def receive: Receive = {
    case StartTicker =>

      runnable.run() …

我有以下代码，但无法编译：

import java.time.Instant

import io.circe.{Decoder, Encoder}
import io.circe.generic.auto._
import io.circe.syntax._

trait SapHealth {}

case class SapHealthRejected(reason: String) extends SapHealth

case class SapHealthAccepted(sapId: String, requestedAt: Long) extends SapHealth


object SapHealth {

  private val build: SapHealth = SapHealthAccepted(SapmockActor.system.name, Instant.now().getEpochSecond)

  val create: String = build.asJson.noSpaces

  implicit val encodeFieldType: Encoder[SapHealthAccepted] =
    Encoder.forProduct2("sap-id", "requested_at")(SapHealthAccepted.unapply(_).get)

  implicit val decodeFieldType: Decoder[SapHealthAccepted] =
    Decoder.forProduct2("sap-id", "requested_at")(SapHealthAccepted.apply)

}

编译器抱怨：

could not find implicit value for parameter encoder: io.circe.Encoder[com.sweetsoft.SapHealth]
[error]   val create: String = build.asJson.noSpaces

我缺少什么？

我正在尝试按以下方式部署港口：

helm install hub harbor/harbor \
  --namespace prod \
  --set expose.ingress.hosts.core=hub.service.example.io \
  --set expose.ingress.annotations.'kubernetes\.io/ingress\.class'=contour \
  --set expose.ingress.annotations.'cert-manager\.io/cluster-issuer'=letsencrypt-prod \
  --set expose.ingress.annotations.'ingress\.kubernetes\.io/force-ssl-redirect'="true" \
  --set expose.ingress.annotations.'kubernetes\.io/tls-acme'="true" \
  --set externalURL=https://hub.service.example.io \
  --set expose.tls.secretName=secret \
  --set notary.enabled=false \
  --set secretkey=secret \
  --set harborAdminPassword=serect  

我有：

Error: unable to build kubernetes objects from release manifest: unable to decode "": resource.metadataOnlyObject.ObjectMeta: v1.ObjectMeta.Annotations: ReadString: expects " or n, but found t, error found in #10 byte of ...|edirect":true,"ingre|..., bigger context ...|prod","ingress.kubernetes.io/force-ssl-redirect":true,"ingress.kubernetes.io/proxy-body-size":"0","i|...  

我究竟做错了什么？