sig
type id
val to_int : Rapids.ID.id -> int
val from_int : int -> Rapids.ID.id
val compare : Rapids.ID.id -> Rapids.ID.id -> int
val succ : Rapids.ID.id -> Rapids.ID.id
val scribe : 'a Conduit.conduit -> 'a -> Rapids.ID.id -> unit
val zero : Rapids.ID.id
val sweep : Rapids.ID.id -> (Rapids.ID.id -> unit) -> unit
val io : Rapids.ID.id Io.literate
end