You can search for identifiers within the package.
in-package search v0.2.0
type t =
| String of string
| Exn of exn * string
val string : ('a, unit, string, ('b, t) result) format4 -> 'a
val exn : exn -> ('a, unit, string, ('b, t) result) format4 -> 'a
val catch_exn : (unit -> 'a) -> (('a, 'b) result, unit, string, ('c, t) result) format4 -> ('a, 'b) result
val to_string : t -> string
val throw : ('a, t) result -> 'a