Untitled

type
  Node = ref object of RootObj
    prev, next: Node
    data: string

  List = ref object of RootObj
    starting, ending: Node
    count: int

proc addItem( list: List, val: string ): int =
  if list.count == 0:
    list.starting = Node()
    list.starting.data = val
    list.ending = list.starting
  else:
    list.ending.next = Node()
    list.ending.next.prev = list.ending
    list.ending = list.ending.next

  list.ending.data = val
  list.count += 1
  result = list.count

proc delItem( list: List, val: string ): int =
  if list.count == 0: return -1

  var itr = list.starting

  while itr != nil:
    if itr.data == val:
      break
    itr = itr.next

  if itr == nil: return -1

  if itr.prev != nil:
    itr.prev.next = itr.next
  if itr.next != nil:
    itr.next.prev = itr.prev

  itr = nil
  list.count -= 1
  result = list.count

iterator items( list: List ): string =
  var itr = list.starting
  while itr != nil:
    yield itr.data
    itr = itr.next

if isMainModule:
  var list: List = List( starting: nil, ending: nil, count: 0 )
  echo addItem( list, "hello" )
  echo addItem( list, "world" )
  for item in list:
    echo item

  echo delItem( list, "world" )
  for item in list:
    echo item