Little Multiple Choice Programm

MultipleChoice.scala

import util.Random
import io.Source

object MultipleChoice extends App {
  
  implicit def colorString(string: String) = new ColoredString(string)
  
  val buffer = Source fromFile "mc.txt"
  val Line = """^([wf]):(.+)$""".r
  val questions = buffer.getLines flatMap (_ match {
    case Line(answer, text) => Some(Question(0, answer head, text))
    case _ => None
  })
  
  clear()
  loop(questions toList)
  
  def loop(questions: List[Question]) {
    val sorted = questions sortBy { case Question(correct, _, _) => (correct, Random nextInt) }
    val (top5, rest) = sorted splitAt 5
    val top5shuffled = Random shuffle top5
    val question @ Question(correct, answer, text) = top5shuffled.head
    val isCorrect = ask(question)
    val updatedQuestion = if (isCorrect) question.succeeded else question.failed
    loop(updatedQuestion :: top5shuffled.tail ::: rest)
  }
  
  def ask(question: Question): Boolean = {
    val Question(_, answer, text) = question
    println("Eingeben: wahr -> w, falsch -> f, quit -> q\n\n"+text.blue)
    val isCorrect = Console readChar match {
      case 'q' => System exit 1; false
      case c: Char => answer == c
    }
    clear()
    val correct = if (isCorrect) "richtig" else "falsch"
    val coloredText = if (answer == 'w') text.green else text.red
    println("Deine Antwort war %s!\n%s\n\n\n".format(correct, coloredText))
    return isCorrect
  }
  
  def clear(): Unit = (0 to 100) foreach (_ => println(""))
    
  case class Question(correct: Int, answer: Char, text: String) {
    def succeeded = Question(correct+1, answer, text)
    def failed = Question(correct-1, answer, text)
  }
  
  class ColoredString(string: String) {
    def blue = Console.BLUE+string+Console.RESET
    def green = Console.GREEN+string+Console.RESET
    def red = Console.RED+string+Console.RESET
  }
  
}

// "mc.txt" file syntax:
// w:Die Klasse String ist final.
// f:Jede Klasse besitzt einen Namen.