You can search for identifiers within the package.
in-package search v0.2.0
type 'a data
type 'a patch
val merge : 'a patch -> 'a data -> 'a data
val map_patch : ('a -> 'b) -> 'a patch -> 'b patch
val map_data : ('a -> 'b) -> 'a data -> 'b data
val empty : 'a data