Actor act() and -Ytailrecommend

On Fri, Apr 09, 2010 at 01:24:29PM -0700, eric so wrote:
> I was playing around with -Ytailrecommend and was surprised it didn't
> warn me with @tailrecommended in the code below (taken from Odersky et
> al."Programming in Scala").

Well, I hope it's clear that "-Y" options are totally hidden for a
reason and might do anything up to and including deleting your whole
source tree and chasing you with a stick.

> def act() {
> react {
> case (name: String, actor: Actor) =>
> actor ! getIp(name)
> act()
> case "EXIT" =>
> println("Name resolver exiting.")
> // quit
> case msg =>
> println("Unhandled message: "+ msg)
> act()
> }
> }

What is the last action in that method? It's not a call to act().
Follow the braces. (Starts with r, ends with t, has an act in the
middle.)

Well, I hope it's clear that "-Y" options are totally hidden for a
reason and might do anything up to and including deleting your whole
source tree and chasing you with a stick.

What is the last action in that method? It's not a call to act().
Follow the braces.  (Starts with r, ends with t, has an act in the
middle.)

--
Paul Phillips      | It's better to have gloved and tossed than never to
Stickler           | have played baseball.
Empiricist         |
i pull his palp!   |----------* http://www.improving.org/paulp/ *----------

On Fri, Apr 09, 2010 at 01:24:29PM -0700, eric so wrote:
> I was playing around with -Ytailrecommend and was surprised it didn't
> warn me with @tailrecommended in the code below (taken from Odersky et
> al."Programming in Scala").

Well, I hope it's clear that "-Y" options are totally hidden for a
reason and might do anything up to and including deleting your whole
source tree and chasing you with a stick.

>   def act() {
>     react {
>       case (name: String, actor: Actor) =>
>         actor ! getIp(name)
>         act()
>       case "EXIT" =>
>         println("Name resolver exiting.")
>         // quit
>       case msg =>
>         println("Unhandled message: "+ msg)
>         act()
>     }
>   }

What is the last action in that method? It's not a call to act().
Follow the braces.  (Starts with r, ends with t, has an act in the
middle.)

--
Paul Phillips      | It's better to have gloved and tossed than never to
Stickler           | have played baseball.
Empiricist         |
i pull his palp!   |----------* http://www.improving.org/paulp/ *----------

I was playing around with -Ytailrecommend and was surprised it didn't warn me with @tailrecommended in the code below (taken from Odersky et al. "Programming in Scala").

I put @tailrec on act and the compiler complained.  I made act final, and the compiler still complained.  Ok, act can't have the tailrec optimization?  Do I not need to worry about this?

object NameResolver extends Actor {
  import java.net.{InetAddress, UnknownHostException}




  def act() { 
    react {



      case (name: String, actor: Actor) =>
        actor ! getIp(name)



        act()
      case "EXIT" =>



        println("Name resolver exiting.")
        // quit



      case msg =>
        println("Unhandled message: "+ msg)



        act()
    }



  }

  def getIp(name: String): Option[InetAddress] = {



    try {
      Some(InetAddress.getByName(name))



    } catch {
      case _:UnknownHostException => None



    }
  }
}

On Fri, Apr 09, 2010 at 01:51:07PM -0700, eric so wrote:
> I thought you were rather recommending it here:

There's no conflict between suggesting people use it and there being no
guarantee whatsoever about what it will do. Really the point is that we
want to make it available in case it's useful, but with zero support.

There's no conflict between suggesting people use it and there being no
guarantee whatsoever about what it will do.  

Really the point is that we
want to make it available in case it's useful, but with zero support.