+(* FG *)
+let quad fst_unmarshaller snd_unmarshaller trd_unmarshaller fth_unmarshaller v =
+ match Str.split spaces_rex v with
+ | [fst; snd; trd; fth] -> fst_unmarshaller fst, snd_unmarshaller snd, trd_unmarshaller trd, fth_unmarshaller fth
+ | _ -> raise (Type_error "not a quad")
+