lists.ml

let max_length header rows = 
  let lengths list = List.map ~f:String.length list in
  List.fold rows
    ~init: (lengths header)
    ~f: (fun acc row ->
      List.map2_exn ~f:Int.max acc (lengths row))

let make_separator widths = 
  let pieces = List.map widths 
    ~f:(fun w -> String.make (w + 2) '-') (* padding of 2 chars *)
  in
  "|" ^ String.concat ~sep:"+" pieces ^ "|"