type bsonvalue =
  | BDouble of float
  | BString of string
  | BObject of bsondoc
  | BArray of list bsonvalue
  | BBinary of int * string
  | BUndefined
  | BOid of string
  | BBool of bool
  | BDate of int64
  | BNull
  | BEoo
  | BRegEx of string * string
  | BRef of string * string
  | BCode of string
  | BReserved2
  | BScopedCode of string
  | BInt of int32
  | BLong of int64
  | BTimestamp of int64
  | BSymbol of string
  | BCodeScoped of int32 * string * bsondoc

type bsondoc = (string * bsonvalue) list