You can search for identifiers within the package.
in-package search v0.2.0
type 'src t
type 'src write = (module Write with type t = 'src)
val of_write_src : 'src. 'src write -> 'src -> 'src t
val write : 'src t -> data:Buffer.t -> (int, [> `Closed ]) result
module Make (B : Write) : sig ... end