type 'a t = UTF8.Buffer.buffer -> unit type 'a obs = UTF8.Buffer.buffer -> unit let cell t buffer = UTF8.Buffer.add_string buffer @@ Cell.to_string t let range c1 c2 buffer = Tools.Tuple2.printb ~first:"" ~last:"" ~sep:":" Cell.to_buffer Cell.to_buffer buffer (c1, c2) let observe elem buffer = elem buffer