add ?margin parameter to CCFormat.ksprintf

src/core/CCFormat.ml

@@ -383,10 +383,11 @@ let fprintf_dyn_color ~colors out fmt =
   assert_equal "yolo" (sprintf_no_color "@{<red>yolo@}");
 *)
 
-let ksprintf ~f fmt =
+let ksprintf ?margin ~f fmt =
   let buf = Buffer.create 32 in
   let out = Format.formatter_of_buffer buf in
   if !color_enabled then set_color_tag_handling out;
+  begin match margin with None -> () | Some m -> pp_set_margin out m end;
   Format.kfprintf
     (fun _ -> Format.pp_print_flush out (); f (Buffer.contents buf))
     out fmt

src/core/CCFormat.mli

@@ -273,11 +273,13 @@ val fprintf_dyn_color : colors:bool -> t -> ('a, t, unit ) format -> 'a
     @since 0.21 *)
 
 val ksprintf :
+  ?margin:int ->
   f:(string -> 'b) ->
   ('a, Format.formatter, unit, 'b) format4 ->
   'a
 (** [ksprintf fmt ~f] formats using [fmt], in a way similar to {!sprintf},
     and then calls [f] on the resulting string.
+    @param margin set margin (since NEXT_RELEASE)
     @since 0.14 *)
 
 val to_file : string -> ('a, t, unit, unit) format4 -> 'a