Guild

Simple, fast actors for Scala.

Requirements

• Java SE 6
• Scala 2.8 Beta1
• JetLang 0.2.0

How To Use

First, specify Metrics as a dependency:

val codaRepo = "Coda Hale's Repository" at "http://repo.codahale.com/"
val guild = "com.codahale" % "guild_2.8.0.Beta1" % "0.1.0" withSources()

(Or whatever gets Ivy or Maven to work for you.)

Second, write an actor:

import com.codahale.guild.Actor

class MyActor extends Actor[Any, Any] {
  def onMessage(msg: Any) = {
    msg match {
      case i: Int => i + i
      case s: String => println("Hello " + s)
    }
  }
}

(Yes, that's it. No partially applied functions, just a method.)

Third, start the actor:

val actor = new MyActor
actor.start()

Fourth, send the actor a message asynchronously:

// prints out "Hello world!"
actor.send("world!")

Fifth, synchronously send the actor a message and get a response:

// prints out "40"
println(actor.call(20))

(No, there isn't a ! method or a !? method or a \m/ method. If you feel that they add clarity to your code, feel free to add them to a trait and extend your actor classes with them.)

For your Asynchronous Message-Passing Merit Badge, check out actor pools, which dispatch messages to a pool of actor workers:

import com.codahale.guild.{Actor, ActorFactory, ActorPool}

class StringCounter extends Actor[String, Int] {
  def onMessage(s: String) = s.length
}

class StringCounterFactory extends ActorFactory[String, Int, StringCounter] {
  def createActor() = new StringCounter
}

val factory = new StringCounterFactory
val counterPool = new ActorPool(factory)

pool.start(4) // start up 4 instances of StringCounter
pool.call("yesssss")
pool.stop()

License

Copyright (c) 2010 Coda Hale; Published under The MIT License, see LICENSE.