uniqueHash.scala

/* http://tbje.blogspot.com/2010/04/random-unique-hash-in-scala.html */
import scala.util.Random

def uniqueRandomKey(chars: String, 
  length: Int, 
  uniqueFunc: String=>Boolean) : String = 
{ 
    
    val newKey = (1 to length).map(
        x =>
        {
          val index = Random.nextInt(chars.length)
          chars(index)
        } 
        ).mkString("")
    if (uniqueFunc(newKey)) 
      newKey 
    else 
      uniqueRandomKey(chars, length, uniqueFunc)
}

/**
 * implement your own is unique here
 */
def isUnique(s:String):Boolean = true

val chars = ('a' to 'z') ++ ('A' to 'Z') ++ ('0' to '9') ++ ("-!£$")
val key = uniqueRandomKey(chars.mkString(""), 8, isUnique)


println(key)