You can search for identifiers within the package.
in-package search v0.2.0
websocket
Websocket.Option
val value : default:'a -> 'a option -> 'a
val value_exn : 'a option -> 'a
val value_map : default:'b -> f:('a -> 'b) -> 'a option -> 'b
val map : f:('a -> 'b) -> 'a option -> 'b option