You can search for identifiers within the package.
in-package search v0.2.0
type nonrec 'a t = 'a t
val return : 'a -> 'a t
val catch : (unit -> 'a t) -> ('a, exn) Pervasives.result t
val don't_wait_for : (unit -> unit t) -> unit
val sleepf : float -> unit t
val fail : exn -> 'a t
module Infix : sig ... end