debasishg

1. Go back to the first shell
2. Sub.unsub("a") // should unsubscribe the first shell from channel "a"
3. Study the callback function defined below. It supports many other message formats.
4. In the second shell window do the following:

  scala> Pub.publish("b", "+c")  // will subscribe the first window to channel "c"
  scala> Pub.publish("b", "+d")  // will subscribe the first window to channel "d"
  scala> Pub.publish("b", "-c")  // will unsubscribe the first window from channel "c"
  scala> Pub.publish("b", "exit")  // will unsubscribe the first window from all channels

debasishg

newOrder.to.buy(100.shares.of('IBM')) {
  limitPrice   300
  allOrNone    true
  valueAs      {qty, unitPrice -> qty * unitPrice - 500}
}

debasishg

def dslDef = new File('ClientOrder.groovy').text
def dsl = new File('order.dsl').text
def script = """
  ${dslDef}
  ${dsl}
"""
new GroovyShell().evaluate(script)

debasishg

ScriptEngineManager factory = new ScriptEngineManager();
ScriptEngine engine = factory.getEngineByName("groovy");

List<?> orders = (List<?>)
  engine.eval(new InputStreamReader(
    new BufferedInputStream(
      new SequenceInputStream(
        new FileInputStream("ClientOrder.groovy"),
        new FileInputStream("order.dsl")))));

debasishg

public class RunScript {
  public static void main(String[] args)
    throws CompilationFailedException, IOException,
           InstantiationException, IllegalAccessException {

    final ClientOrder clientOrder = new ClientOrder();

    clientOrder.run();

    final Closure dsl = 

debasishg

module BatchedQueue (BatchedQueue) where
  import Prelude hiding (head, tail)
  import Queue

  data BatchedQueue a = BQ [a] [a]

  check [] r = BQ (reverse r) []
  check f r = BQ f r

  instance Queue BatchedQueue where

debasishg

case class Holder(item: List[String])
implicit val HolderFormat: Format[Holder] = wrap[Holder, List[String]]("item")(_.item, Holder)

// instantiate the case class
val n = Holder(List("debasish ghosh", "jonas boner", "stephan schmidt"))

// js is a JsValue
val js = tojson(n)

// convert js to string and print

debasishg

// a simple POJO
case class Address(street: String, city: String, zip: String)
object AddressProtocol extends DefaultProtocol {
    implicit val AddressFormat: Format[Address] = 
      asProduct3("street", "city", "zip")(Address)(Address.unapply(_).get)
}

// aggregate containing list
case class Contact(name: String, addresses: List[Address])

debasishg

object Protocols {
  import dispatch.json._
  trait HttpType
  implicit val HttpTypeFormat: Format[HttpType] = new Format[HttpType] {
    def reads(json: JsValue): HttpType = json match {
      case JsString("Get") => Get
      case JsString("Post") => Post
      case _ => error("Invalid HttpType")
    }
    def writes(a: HttpType): JsValue = a match {

debasishg

trait Read[T] {
  def read(st: String): T
}

implicit object IntRead extends Read[Int] {
  def read(s: String) = s.toInt
}

implicit object StringRead extends Read[String] {
  def read(s: String) = s