sig type t val create : int ->Buffer.t val contents : Buffer.t -> string val length : Buffer.t -> int val clear : Buffer.t -> unit val reset : Buffer.t -> unit val add_char : Buffer.t -> char -> unit val add_string : Buffer.t -> string -> unit val add_substring : Buffer.t -> string -> int -> int -> unit val add_buffer : Buffer.t ->Buffer.t -> unit val add_channel : Buffer.t ->Pervasives.in_channel -> int -> unit val output_buffer : Pervasives.out_channel ->Buffer.t -> unit