val pp :
Ppx_deriving_runtime.Format.formatter ->
t ->
Ppx_deriving_runtime.unit
val show : t -> Ppx_deriving_runtime.string
val equal : t -> t -> Ppx_deriving_runtime.bool
val unimplemented : ?issue_id:int -> ?details:string -> Ast.span -> 'a
val assertion_failure : Ast.span -> string -> 'a