You can search for identifiers within the package.
in-package search v0.2.0
rio
Rio.Bytes
type t = bytes
val empty : t
val with_capacity : int -> t
val length : t -> int
val sub : t -> pos:int -> len:int -> t
val of_string : string -> t
val to_string : t -> string
val split : ?max:int -> on:string -> t -> t list
val join : t -> t -> t
module Bytes_writer : sig ... end
val to_writer : t -> Bytes_writer.t Writer.t