oxbowlakes

object OptionGolf {
  import scalaz._
  import Scalaz._

  val moviel = Map("title" -> "South Park",
		  "user" -> "Terrence",
		  "rating" -> "3")

  val incompleteMovie = Map("name" -> "Jaws")

oxbowlakes

package test

import scalaz._
import Scalaz._
import test.IRange.Increment

sealed trait Limit[+Z] {
  def open : Boolean
  def bound : Option[Z]
  final def closed = !open

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._

oxbowlakes

<?xml version="1.0" encoding="UTF-8"?>
<scheme name="oxbow" version="1" parent_scheme="Default">
  <option name="LINE_SPACING" value="1.0" />
  <option name="EDITOR_FONT_SIZE" value="12" />
  <option name="EDITOR_FONT_NAME" value="Consolas" />
  <colors />
  <attributes>
    <option name="ABSTRACT_CLASS_NAME_ATTRIBUTES">
      <value>
        <option name="FOREGROUND" value="666666" />

oxbowlakes

<?xml version="1.0" encoding="UTF-8"?>
<scheme name="OxbowSolarizedDark" version="1" parent_scheme="Default">
  <option name="LINE_SPACING" value="1.2" />
  <option name="EDITOR_FONT_SIZE" value="13" />
  <option name="EDITOR_FONT_NAME" value="Consolas" />
  <colors>
    <option name="ADDED_LINES_COLOR" value="" />
    <option name="ANNOTATIONS_COLOR" value="2b36" />
    <option name="ANNOTATIONS_MERGED_COLOR" value="" />
    <option name="CARET_COLOR" value="dc322f" />

oxbowlakes

Welcome to Scala version 2.9.1.final (Java HotSpot(TM) Server VM, Java 1.6.0_18).
Type in expressions to have them evaluated.
Type :help for more information.

scala> type Tagged[U] = { type Tag = U }
defined type alias Tagged

scala> type @@[T, U] = T with Tagged[U]
defined type alias $at$at

oxbowlakes

scala> (1 to 20).toList
res1: List[Int] = List(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)

//Simple side effects
scala> res1 take 3 foreach (i => println(i))
1
2
3

scala> res1 take 3 foreach println

oxbowlakes

object GOption {
  def some[A](a: A): GOption[A] = new GOption[A] { 
    def cata[B](n: => B, s: A => B): B = sys.error("Implement me") 
  }
  def none[A]: GOption[A] = new GOption[A] { 
    def cata[B](n: => B, s: A => B): B = sys.error("Implement me") 
  }
}

trait GOption[+A] {

oxbowlakes

trait MyList[+A] { 
  def fold[B](k: Option[(A, B)] => B): B
  def map[B](f: A => B): MyList[B]             = sys.error("Implement me in terms of fold")
  def flatMap[B](f: A => MyList[B]): MyList[B] = sys.error("Implement me in terms of fold")
  def headOption: Option[B]                    = sys.error("Implement me in terms of fold")
  def tailOption: Option[MyList[B]]            = sys.error("Implement me in terms of fold")
  def isEmpty                                  = sys.error("Implement me in terms of fold")
  def length                                   = sys.error("Implement me in terms of fold")
}

oxbowlakes

import java.util.Currency

object Fx {
  type CcyPair = (Currency, Currency)
  case class FxRate(from: Currency, to: Currency, rate: BigDecimal) {
    def pair: CcyPair = from → to
    def unary_~ = FxRate(to, from, 1 / rate)
    def *(that: FxRate): FxRate = {
      require(this.to == that.from)
      FxRate(this.from, that.to, this.rate * that.rate)