(** {2 List processing} *)
-val list_uniq: 'a list -> 'a list (* uniq unix filter on lists *)
-val filter_map: ('a -> 'b option) -> 'a list -> 'b list (* filter + map *)
+val list_uniq: 'a list -> 'a list (** uniq unix filter on lists *)
+val filter_map: ('a -> 'b option) -> 'a list -> 'b list (** filter + map *)
+val list_concat: ?sep:'a list -> 'a list list -> 'a list (**String.concat-like*)
(** {2 Debugging & Profiling} *)