在Scala中使用运算符orElse的正确方法是什么？

我想编写两个服务，然后使用orElse使这两个服务组合在一起，这意味着服务1或服务2。他们都是 部分功能

服务一是：

val usersService = HttpService {
case request @ GET -> Root / "users" / IntVar(userId) =>
  Ok("test")
}

服务二是：

val versionService = HttpService{
  case req @ GET -> Root / "version" => {
    val jsonmap = ("origin" -> req.remoteAddr.getOrElse("unknown ip"))
    Ok(compact(render(jsonmap)))
   }
}

然后我想结合在一起

val service = userService orElse versionService   //the error happens here.

错误是：

[error] F:\workspace\frankcheckAPI\src\main\scala\com\cardaccess\ServiceApp.scala:46: value orElse is not a member of org.http4s.HttpService
[error]   val service = usersService orElse versionService
[error]                              ^
[error] one error found
[error] (compile:compileIncremental) Compilation failed

如何组合然后使其工作就像如果案例匹配第一个服务的路径第一个服务工作，如果案例匹配第二个服务的路径。第二项服务工作

附：有关人士：

HttpService对象的定义如下：

  type HttpService = Service[Request, Response]
  object HttpService {

/** Alternative application which lifts a partial function to an `HttpService`,
  * answering with a [[Response]] with status [[Status.NotFound]] for any requests
  * where the function is undefined.
  */
def apply(pf: PartialFunction[Request, Task[Response]], default: HttpService = empty): HttpService =
  Service.lift(req => pf.applyOrElse(req, default))
...
}

orElse与PartialFunction一起使用，例如：

val t1: PartialFunction[Int, String] = {case 1 => "I am 1"}
val t2: PartialFunction[Int, String] = {case 2 => "I am 2"}
val t = t1 orElse t2
t(1)
> I am 1
t(2)
> I am 2

作为HttpService的apply方法签名接受PartialFunction，我认为您可以这样做：

val usersService: PartialFunction[Request, Task[Response]] = {
  case request @ GET -> Root / "users" / IntVar(userId) =>
    Ok("test")
}

val versionService: PartialFunction[Request, Task[Response]] = {
  case req @ GET -> Root / "version" => {
    val jsonmap = ("origin" -> req.remoteAddr.getOrElse("unknown ip"))
    Ok(compact(render(jsonmap)))
   }
}
val service = HttpService {
  usersService orElse versionService
}

---

我添加了定义的HttpService对象@chengpohi@user504909，很好，添加示例。不要认为此“服务”有效，因为“userService”和“versionService”都不是PartialFunction，而是服务实例。另外，请选择，然后重试。。非常方便。什么是服务？您使用的是哪种框架？