gistfile1.ml

class stack_of_ints =
  object (self)
    val mutable the_list = ( [] : int list )   (* instance variable *)
    method push x =                        (* push method *)
      the_list <- x :: the_list
    method pop =                           (* pop method *)
      let result = hd the_list in
      the_list <- tl the_list;
      result
    method peek =                          (* peek method *)
      hd the_list
    method size =                          (* size method *)
      length the_list
  end;;