Modulo10 Rekursiv in Gosu

ModuloTenRecursive.gs

uses java.lang.Character
uses java.lang.Integer
uses java.util.ArrayList

class ModuloTenRecursiveProcessor {

  /**
   * Validate a number string using Modulo10 rekursiv
   */
  public static function checkSum(numberString:String):int {

    // pattern to allow recursive solution. 
    var table: int[] = { 0, 9, 4, 6, 8, 2, 7, 1, 3, 5 }
    
    var carryForward: int = 0

    var numberArray: List<Integer> = convertToNumberArray(numberString)

    for (number in numberArray)
    {
      carryForward = table[(carryForward + number) % 10]
    }

    return (10 - carryForward) % 10
  }

  /**
   * Returns given String as array of digits. Whitespaces will be removed
   */
  @Param ( "numberString", "Number to be converted" )
  @Returns ( "Array of digits" )
  private static function convertToNumberArray(numberString:String) : List<Integer> {

    var numberArray:List<Integer> = new ArrayList<Integer>(numberString.length)

    for (var myChar in numberString.toCharArray() index i) {
      if (Character.isDigit(myChar)) {
        numberArray.add(Character.getNumericValue(myChar))
      }
    }
    return numberArray
  }

}