debasishg

scala> import scalaz._
import scalaz._

scala> import Scalaz._
import Scalaz._

scala> case class Address(no: Int, street: String, zip: String)
defined class Address

// this can be generated

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 =>

debasishg

import scalaz._
import Scalaz._

def charLineCount[T[_]:Traverse](t: T[Char]) =
  t.traverse[({type λ[x] = State[(Int, Int),x]})#λ, (Int, Int)](a =>
    state((counts: (Int, Int)) =>
      ((counts._1 + 1, counts._2 + (if (a == '\n') 1 else 0)), (counts._1, counts._2)))) ! (1,1)

println(charLineCount("the cat in the hat\n sat on the mat\n".toList).last) // (35, 2)

debasishg

// disperse implementation corresponding to the same function in section 4.2 of the paper
// Essence of the Iterator Pattern
def disperse[T[_]:Traverse, A, S, B](t: T[A], s: A => State[S, B]) =
  t.traverse[({type λ[x] = State[S,x]})#λ, B](s)

// implementing a labeling function, also from section 4.2
// labeling every element with its position in order of traversal
def label_[T[_]:Traverse, A](t: T[A]) = disperse(t, ((a: A) => state((i: Int) => (i+1, i)))) ! 0

println(label_(List(102, 207, 876, 14)) // List(0,1,2,3)

debasishg

// client orders           executed at market by broker        & allocated to client accounts
kleisli(clientOrders) >=> kleisli(execute(market)(broker)) >=> kleisli(allocate(clientAccounts))

debasishg

package akka.persistence.redis

import org.scalatest.junit.JUnitSuite

import org.junit.{Test, Before}
import org.junit.Assert._

import akka.actor.{Actor, ActorRef}
import akka.actor.Actor._
import akka.stm._

debasishg

// works for Validation

scala> val a: Validation[String, Int] = 1.success
a: scalaz.Validation[String,Int] = Success(1)

scala> val b: Validation[String, Int] = 2.success
b: scalaz.Validation[String,Int] = Success(2)

scala> val c: Validation[String, Int] = 3.success
c: scalaz.Validation[String,Int] = Success(3)

debasishg

scala> val d: Validation[String, Int] = 12.success
d: scalaz.Validation[String,Int] = Success(12)

scala> val e: Validation[String, String] = "ghosh".success
e: scalaz.Validation[String,String] = Success(ghosh)

scala> (d, e)
res18: (scalaz.Validation[String,Int], scalaz.Validation[String,String]) = (Success(12),Success(ghosh))

// I want to get Validation[String, (Int, Int)] out of this. The closest I could get is ..

debasishg

val jsonString = 
  """{
       "lastName" : "ghosh", 
       "firstName" : "debasish", 
       "age" : 20, 
       "address" : { "no" : 12, "street" : "Monroe Street", "city" : "Denver", "zip" : "80231" }, 
       "phone" : { "no" : "3032144567", "ext" : 212 },
       "office" :
        {
          "name" : "anshinsoft",

debasishg

// like to keep domain objects pure
// hence moved repository injection to the service module

case class User(name: String)

trait UserRepository{
  def save(user: User): Unit
}

class RiakUserRepository extends UserRepository{