scalaz.effectsを試したり

io.scala

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

val i = for {
  _ <- putStrLn("Greetings! What is your name?")
  inpStr <- readLn
  outStr = "Welcome to Scalaz, " |+| inpStr |+| "!"
  _ <- putStrLn(outStr)
} yield ()

val i2 = putStrLn("Greetings! What is your name?") >|> readLn >>= { inpStr =>
  val outStr = "Welcome to Scalaz, " |+| inpStr |+| "!"
  putStrLn(outStr)
}

val i3 = for {
  v <- newIORef("Scala")
  _ <- v.write("Clojure")
  _ <- v.mod(_ |+| "Tan")
  s <- v.read
  _ <- putStrLn(s)
} yield ()

iter.scala

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

val file = new java.io.File("test.txt")

val file2 = new java.io.File("test2.txt")

val i = for {
  s <- for {
    f <- getFileLines(file)(collect[String, List])
  } yield f.run
  outStr = s.mkString("\n")
  _ <- putStrLn(outStr)
} yield ()

val i2 = for {
  s <- for {
    f <- getFileLines(file)(length)
    f2 <- getFileLines(file2)(f)
  } yield f2.run
  _ <- putOut(s)
} yield ()

st.scala

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

val f = new Forall[({type X[S] = ST[S, String]})#X] {
  def apply[A] = for {
    v <- newVar[A, String]("Scala")
    _ <- v.mod(_ |+| "Chan")
    s <- v.read
  } yield s
}

val f2 = new Forall[({type X[S] = ST[S, ImmutableArray[String]]})#X] {
  def apply[A] = for {
    v <- newArr[A, String](5, "Scala")
    _ <- v.write(1, "Clojure")
    _ <- v.write(2, "Haskell")
    _ <- v.write(3, "Python")
    _ <- v.write(4, "JRuby")
    a <- v.freeze
  } yield a
}