In Scala how do I remove duplicates from a list?

Question

Suppose I have

val dirty = List(\"a\", \"b\", \"a\", \"c\")

Is there a list operation that returns \"a\", \"b\", \"c\"

Answer 1

The algorithmic way...

def dedupe(str: String): String = {
  val words = { str split " " }.toList

  val unique = words.foldLeft[List[String]] (Nil) {
    (l, s) => {
      val test = l find { _.toLowerCase == s.toLowerCase } 
      if (test == None) s :: l else l
    }
  }.reverse

  unique mkString " "
}