Past exam of the year 1 of the computer science course of the University of Oxford / 2022 / Imperative programming (resit) / 7 / a / iv

def unitIter[T](t: T): Iter[T] = new Iter[T] {
  private var available = true
  def hasNext: Boolean = available
  def next(): T = {
    require(available, "empty iterator")
    available = false
    t
  }
}

def unitCursor[T](t: T): Cursor[T] = new Cursor[T] {
  private var available = true
  def hasCurrent: Boolean = available
  def current: T = {
    require(available, "empty cursor")
    t
  }
  def next(): Unit = {
    require(available, "empty cursor")
    available = false
  }
}