val set : t -> path -> value option -> unit
(** [set t path] sets [value] as new value at [path]. *)
+val setm : t -> path -> string option -> value option -> int
+ (** [setm t base sub value] sets [value] as new value for all the
+ nodes under [base] that match [sub] (or all, if [sub] is
+ [None]).
+
+ Returns the number of nodes modified. *)
+
val transform : t -> string -> string -> transform_mode -> unit
(** [transform t lens file mode] adds or removes (depending on
[mode]) the transformation of the specified [lens] for [file]. *)