ISO 7064 MOD 11,10 Control character calculator

Iso7064Util.scala

object Iso7064Util {

  object Mod_11_10 {
    def calculateControlChar(input: String): String = {
      var rest = 10
      input.map(_.asDigit).foreach { num =>
        val sum = num + rest
        val subtotal = if (sum % 10 == 0) 10 else sum % 10
        rest = (subtotal * 2) % 11
        //println(s"digit=$num\tsum=$sum\tsubtotal=$subtotal\trest=$rest")
      }

      val control = if (rest == 1) 0 else 11 - rest

      control.toString
    }
  }

}