You can search for identifiers within the package.
in-package search v0.2.0
type t = Async.Reader.t * Async.Writer.t
val read : t -> Cstruct.t -> [ `Ok of int | `Eof ] Async.Deferred.Or_error.t
val write_full : t -> Cstruct.t -> unit Async.Deferred.Or_error.t