miloxia/parz

Free Monad for Parallel Computation

Parz

Free Monad for Par
I have not been idle :)

##Open mode

1.Add type

  class IOReq[A] extends Request[A]
  case class Get(q: String) extends IOReq[String]
  case class Put(r: String) extends IOReq[Unit]

2.Add functions

  def get(q: String) = Get(q)
  def put(p: String) = Put(p)
  def add(b: String, c: String) = b + c

3.Add for-comprehension

  val test = for {
    a <- get("get a")
    d <- pure(add _) <*> get("get b") <*> get("get c")
    _ <- put(a+d)
  } yield ()

or for haskell guys

  val addf = (add _).curried
  val test = for {
    a <- get("get a")
    d <- addf `<$>` get("get b") <*> get("get c")
    _ <- put(a+d)
  } yield ()

Monad is express dependent computation
Applicative is express parallel computation (independent computation)

4.Add service

object IOReqService extends Service[IOReq] {
    override def fetch[A](req: IOReq[A]): A = req match {
      case Get(q) =>
        println(q)
        Random.nextString(10)
      case Put(s) =>
        println(s)
    }
  }

5.Add effect & run

implicit val fetchEffect = FetchEffect(IOReqService)

test.run