You can search for identifiers within the package.
in-package search v0.2.0
js_of_ocaml.deriving
Deriving_Json.Json_float
type a = float
val t : a t
val write : Buffer.t -> a -> unit
val read : Deriving_Json_lexer.lexbuf -> a
val to_string : a -> string
val from_string : string -> a