You can search for identifiers within the package.
in-package search v0.2.0
type a
type key = string
type doc = string
type spec =
| Unit of a -> a
| String of string -> a -> a
| Int of int -> a -> a
type anon = string -> a -> a
type error =
| Unknown_option of string
| Missing_argument of key * spec * doc
| Invalid_argument of key * spec * doc * string
val parse : string array -> a -> (key * spec * doc) list -> anon -> (a, error) result
val string_of_error : error -> string
val argument_type : spec -> string