let filename ?(editable=true) ?(expand=true)?help ?(f=(fun _ -> ())) label v =
Filename_param
{
string_label = label ;
string_help = help ;
string_value = v ;
string_editable = editable ;
string_f_apply = f ;
string_expand = expand ;
string_to_string = (fun x -> x) ;
string_of_string = (fun x -> x) ;
}