type entry = string * Stdlib.Digest.t optiontype t = entry listval empty : tval print : Stdlib.out_channel -> t -> unitval read : Index.t -> Stdlib.in_channel -> tval write : Stdlib.out_channel -> t -> unitOByteLib.Crcstype entry = string * Stdlib.Digest.t optiontype t = entry listval empty : tval print : Stdlib.out_channel -> t -> unitval read : Index.t -> Stdlib.in_channel -> tval write : Stdlib.out_channel -> t -> unit