List implementation in Jsonnet

list.libsonnet

{
  head(list)::
    if list == [] then
      error 'Can not take head of empty list'
    else
      list[0],

  tail(list)::
    if list == [] then
      error 'Can not take tail of empty list'
    else
      list[1],

  take(list, n)::
    if n == 0 || list == [] then
      []
    else
      [self.head(list), self.take(self.tail(list), n - 1)],

  length(list)::
    local aux(list, count) =
      if list == [] then
        count
      else
        aux(self.tail(list), count + 1) tailstrict;
    aux(list, 0),

  toArray(list)::
    local aux(list, acum) =
      if list == [] then
        acum
      else
        aux(self.tail(list), acum + [self.head(list)]) tailstrict;
    aux(list, []),

  repeat(x, n=-1)::
    if n == 0 then
      []
    else
      [x, self.repeat(x, n - 1)],
}