case class Expression(rotule: String, word: String)

object Texts {

  def processSentence(str: String) : Map[String, Int] = {

    def loop(strLst: List[String], counter: Map[String, Int]): Map[String, Int] = {

      if (strLst.isEmpty || strLst.tail.isEmpty) {

        counter

      } else {

        val n = Expression(strLst.head, strLst.head) match {
          case Expression("#art", _) => "#art"
          case Expression("#sub", _) => "#sub"
          case Expression("#verbo", _) => "#verbo"
          case Expression("#pron", _) => "#pron"
        }

        if (counter.contains(n))
          loop(strLst.tail.tail, counter - n + (n -> (counter(n) + 1)))
        else
          loop(strLst.tail.tail, counter + (n -> 1))
      }
    }

    val splittedStr = str.split(" ").toList
    loop(splittedStr, Map())

  }

  def main(args: Array[String]) {
    println(processSentence("#art O #sub rato #verbo roeu #art a #sub roupa #pron do #sub rei #pron de #sub roma"))
  }
}