Handling of ansi codes.
val printf : attr list ‑> ('a, Core.Out_channel.t, unit) Core.format ‑> 'a
val eprintf : attr list ‑> ('a, Core.Out_channel.t, unit) Core.format ‑> 'a
val output_string : attr list ‑> Core.Out_channel.t ‑> string ‑> unit
val output : attr list ‑> Core.Out_channel.t ‑> string ‑> int ‑> int ‑> unit
val string_with_attr : attr list ‑> string ‑> string