A little scalaz IO action

gistfile1.scala

import scalaz._
import Scalaz._
import scalaz.effects._

import java.io._

/**
 * Background reading:
 * http://www.stackmob.com/2011/12/scalaz-post-part-2/
 * http://blog.sigfpe.com/2007/11/io-monad-for-people-who-simply-dont.html
 * http://apocalisp.wordpress.com/2011/12/19/towards-an-effect-system-in-scala-part-2-io-monad/
 */
object TheIO extends App {
  
  val dirInIO = io { new File(System.getProperty("user.dir")) }

  def filesInIO = for (dir <- dirInIO) yield dir.listFiles()

  def namesInIO = for (theFiles ← filesInIO) yield theFiles.map(_.getName())

  def printNamesInIO = for (all ← namesInIO) yield all.map(println(_))

  val result = printNamesInIO
  
  println("Nothings happened yet, lets go!")
  result.unsafePerformIO
}

I should say that I decided to tinker with scalaz IO after reading this article: http://www.stackmob.com/2011/12/scalaz-post-part-2/