module Asttypes: sig .. end
type constant = 
| | | Const_int of int | 
| | | Const_char of char | 
| | | Const_string of string * string option | 
| | | Const_float of string | 
| | | Const_int32 of int32 | 
| | | Const_int64 of int64 | 
| | | Const_nativeint of nativeint | 
type rec_flag = 
| | | Nonrecursive | 
| | | Recursive | 
type direction_flag = 
type private_flag = 
type mutable_flag = 
type virtual_flag = 
type override_flag = 
type closed_flag = 
type label = string;
type 'a loc = 'a Location.loc = {
|    | txt : 'a; | 
|    | loc : Location.t; | 
}
type variance = 
| | | Covariant | 
| | | Contravariant | 
| | | Invariant |