You can search for identifiers within the package.
in-package search v0.2.0
type log_level =
| FATAL
| ERROR
| WARN
| INFO
| DEBUG
val set_log_level : log_level -> unit
val set_output : Pervasives.out_channel -> unit
val fatal : string Lazy.t -> unit
val error : string Lazy.t -> unit
val warn : string Lazy.t -> unit
val info : string Lazy.t -> unit
val debug : string Lazy.t -> unit