You can search for identifiers within the package.
in-package search v0.2.0
include IO
type 'a t
val return : 'a -> 'a t
val bind : 'a t -> ('a -> 'b t) -> 'b t
val map : ('a -> 'b) -> 'a t -> 'b t
val finally : (unit -> 'a t) -> ('a -> 'b t) -> (exn -> 'b t) -> 'b t