Digest

`sig type t = string val compare : Digest.t -> Digest.t -> int val equal : Digest.t -> Digest.t -> bool val string : string -> Digest.t val bytes : bytes -> Digest.t val substring : string -> int -> int -> Digest.t val subbytes : bytes -> int -> int -> Digest.t external channel : Pervasives.in_channel -> int -> Digest.t = "caml_md5_chan" val file : string -> Digest.t val output : Pervasives.out_channel -> Digest.t -> unit val input : Pervasives.in_channel -> Digest.t val to_hex : Digest.t -> string val from_hex : string -> Digest.t end`