Scala FizzBuzz

FizzBuzz.scala

object FizzBuzz {
  val defaultRules = List(
    Rule(3, "fizz"),
    Rule(5, "buzz")
  )

  def main(args: Array[String]) = {
    fizzBuzz() foreach(println)
  }

  def fizzBuzz(from: Int = 1, to: Int = 100, rules: Seq[Rule] = defaultRules): Seq[String]  = {
    (from to to).map { i =>
      rules.flatMap { rule =>
        if (rule test(i)) Some(rule word) else None
      }.reduceLeftOption{_ + _}.getOrElse(i toString)
    }
  }

  case class Rule(factor: Int, word: String) {
    def test(x: Int) = x % factor == 0
  }
}