You can search for identifiers within the package.
in-package search v0.2.0
type error
val pp_error : error Fmt.t
type buffer = buffer
type ip = ipv4
type ipaddr = ipv4addr
type ipinput
type 'a io = 'a io
type t = udpv4
val disconnect : t -> unit io
type callback = src:ipaddr -> dst:ipaddr -> src_port:int -> buffer -> unit io
val input : listeners:(dst_port:int -> callback option) -> t -> ipinput
val write : ?src_port:int -> dst:ipaddr -> dst_port:int -> t -> buffer -> (unit, error) Pervasives.result io