Conex_resource.Digesttype t = alg * stringA digest is a pair of digest algorithm and value.
val pp : t Conex_utils.fmtpp digest is a pretty printer for digest.
compare a b compares a and b, returns 0 if equal, -1 if smaller, 1 if bigger.
equal a b is true when a and b use the same algorithm type, and have the same value.
val to_string : t -> stringto_string digest is the string representing the digest.