You can search for identifiers within the package.
in-package search v0.2.0
lsp
Json.Option
type 'a t = 'a option
val yojson_of_t : ('a -> [> `Null ] as 'b) -> 'a option -> 'b
val t_of_yojson : (([> `Null ] as 'a) -> 'b) -> 'a -> 'b option