arnolddevos

import scala.util.continuations._

class Generator[A] extends Iterator[A] with (A => Unit @ suspendable) {
    private var a: Option[A] = None
    private var k: Option[Unit => Unit] = None
    
    def next = {
	val a0 = a.get
	val k0 = k.get
        a = None

krasserm

import Responder._

import scalaz._

object ResponderDemo extends Application {
  import Scalaz._

    // --------------------------------------------------------------------------
    //  Uses Responder (a continuation monad) to compose asynchronous functions. 
    // --------------------------------------------------------------------------

debasishg

import scalaz._
import Scalaz._

val l = List(10, 20, 30, 40)

// loop from The Essence of the Iterator Pattern
// accumulates elements effectfully, but modifies elements purely and independently of accumulation

def loop[T[_]:Traverse, A, B](f: A => B, t: T[A]) =
  t.traverse[({type λ[x] = State[Int,x]})#λ, (B, Int)](a =>

viktorklang

/**
* I had a question directed at me, on how to encode the following scenario in Akka Actors,
* as for Scala Actors one would simply nest the receives.
*
* Recuirements are as follows:
* The first thing the actor needs to do, is to subscribe to a channel of events,
* Then it must replay (process) all "old" events
* Then it has to wait for a GoAhead signal to begin processing the new events
* It mustn't "miss" events that happen between catching up with the old events and getting the GoAhead signal
*/

viktorklang

import scala.collection.mutable.ListBuffer
import akka.actor.{Actor,ActorRef}
import akka.actor.Actor._
import akka.routing.{ Listeners, Listen }

//Represents a domain event
trait Event

//A builder to create domain entities
trait EntityBuilder[Entity] {

debasishg

case class ElectricCar(b: Battery) { def batteryLevel = b.filledPercentage }

case class GasolineCar(g: GasTank) { def gasLevel = g.filledPercentage }

case class Battery(filledPercentage: Int) { def fill: Battery = Battery(100) }

case class GasTank(filledPercentage: Int) { def fill: GasTank = GasTank(100) }

trait Fills[C] {
  def fill(car: C): C

milessabin

// See http://lampsvn.epfl.ch/trac/scala/ticket/967.
//
// Gilles' fix causes the definition of Nat to be rejected with the error 
// "Parameter type in structural refinement may not refer to a type member
// of that refinement". However we can work around the problem by 
// quantifying out the problematic parameter type and reinstating it via
// a generalized type constraint.

type Num = {
  type Rep

debasishg

def enumResultSet[E,A](rs: ResultSet, iter: IterV[E, A], get: ResultSet => IO[E]): IO[IterV[E, A]] = {
    def loop(i: IterV[E, A]): IO[IterV[E, A]] =
      i.fold(done = (_, _) => i.pure[IO],
             cont = k => next(rs) >>= (hasMore =>
                         if (!hasMore) i.pure[IO]
                         else get(rs) >>= (t => loop(k(El(t))))))
    loop(iter)
}

oxbowlakes

/**
 * Part Zero : 10:15 Saturday Night
 *
 * (In which we will see how to let the type system help you handle failure)...
 *
 * First let's define a domain. (All the following requires scala 2.9.x and scalaz 6.0)
 */

import scalaz._
import Scalaz._

jsuereth

package scalaz.example.nio

import scalaz._
import concurrent.Promise
import effects.IO
import nio.sockets._
import nio.Channels._
import Scalaz._
import iteratees._
import java.nio.channels.SocketChannel