type t =
| Could_not_construct of Sexp.t
| String of string
| Exn of exn
| Sexp of Sexp.t
| Tag_sexp of string * Sexp.t * Caml.Lexing.position option
| Tag_t of string * t
| Tag_arg of string * Sexp.t * t
| Of_list of int option * t list
| With_backtrace of t * string
The second argument is the backtrace
The internal representation. It is exposed so that we can write efficient serializers outside of this module.