3pmTea

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

let render_separator padding widths =
    let pieces = List.map widths
        ~f:(fun w -> String.make (w + 2 * padding) '-')
    in