aesthetic in Bencode

.ocamlinit

@@ -6,5 +6,6 @@
 #require "threads";;
 #load "thread_containers.cma";;
 open Gen.Infix;;
+#install_printer Bencode.pretty;;
 (* vim:syntax=ocaml:
 *)

bencode.ml

@@ -83,6 +83,20 @@ let fmt formatter t =
   to_buf b t;
   Format.pp_print_string formatter (Buffer.contents b)
 
+let rec pretty fmt t = match t with
+  | I i -> Format.fprintf fmt "%d" i
+  | S s -> Format.fprintf fmt "@[<h>\"%s\"@]" s
+  | L l ->
+    Format.fprintf fmt "@[<hov 2>[@,";
+    List.iter (fun t' -> Format.fprintf fmt "%a@ " pretty t') l;
+    Format.fprintf fmt "]@]";
+  | D d ->
+    Format.fprintf fmt "@[<hov 2>{@,";
+    SMap.iter
+      (fun k t' -> Format.fprintf fmt "%a -> %a@ " pretty (S k) pretty t')
+      d;
+    Format.fprintf fmt "}@]";
+
 (** {2 Deserialization (decoding)} *)
 
 (** Deserialization is based on the {! decoder} type. Parsing can be

bencode.mli

@@ -49,6 +49,9 @@ val to_string : t -> string
 val to_chan : out_channel -> t -> unit
 val fmt : Format.formatter -> t -> unit
 
+val pretty : Format.formatter -> t -> unit
+  (** Print the tree itself, not its encoding *)
+
 (** {2 Deserialization (decoding)} *)
 
 (** Deserialization is based on the {! decoder} type. Parsing can be