addFull(
      Monad,
      "u",
      "Uniquify",
      List("uniquify"),
      false,
      "a: lst -> a with duplicates removed"
    ) { a =>
      val iter = ListHelpers.makeIterable(a)
      val uniq: LazyList[Option[VAny]] =
        LazyList.unfold(Seq[VAny]() -> 0) { state =>
          if !iter.hasIndex(state._2) then None
          else if state._1.contains(iter.index(state._2)) then
            Some(None, state._1 -> (state._2 + 1))
          else
            Some(
              Some(iter.index(state._2)),

def uniquify(it: VList): VList =
    var ret = it.toList
    for (i <- it)
      if !ret.contains(i) then ret += i
    VList.from(ret)

def uniquify(it: VList): VList =
      val uniq: LazyList[Option[VAny]] =
        LazyList.unfold(Seq[VAny]() -> 0) { state =>
          if !iter.hasIndex(state._2) then None
          else if state._1.contains(iter.index(state._2)) then
            Some(None, state._1 -> (state._2 + 1))
          else
            Some(
              Some(iter.index(state._2)),
              (state._1 :+ iter.index(state._2)) -> (state._2 + 1)
            )
        }

       VList.from(uniq.flatten)

# python equivalent
def uniquify(it):
    seen = []
    index = 0
    while hasIndex(it):
        if it[index] in seen:
            yield it[index]
            seen.append(it[index])
        index += 1

def caseof(s: String): VList =
  VList.from(
    s.map(
      if _.toString.matches("[A-Z]") then 1    // Uppercase
      else
        if _.toString.matches("[a-z]") then 0  // Lowercase
        else -1                                // Non-alphabet
    )
  )

[error] 201 |        if !this.hasIndex(state._2) then None
[error]     |            ^^^^^^^^^^^^^
[error]     |value hasIndex is not a member of object vyxal.VList$package, but could be made available as an extension method.

  def hasIndex(ind: BigInt): Boolean =