val log: string -> unit
+val id: 'a -> 'a
+
val segments_of_string: string list -> int -> string -> string list
-val rev_concat: string -> string -> string list -> string
+val rev_map_concat: ('a -> string) -> string -> string -> 'a list -> string
val fold_string: ('a -> char -> 'a) -> 'a -> string -> 'a