type meth = | PARTIAL| SYNC| FULL
val eval :
'a ->
'a ->
('a, 'a) t ->
[ `Await of ('a, 'a) t
| `Flush of ('a, 'a) t
| `End of ('a, 'a) t
| `Error of ('a, 'a) t * error ]val finish : ('a, 'a) t -> ('a, 'a) tval no_flush : int -> int -> ('a, 'a) t -> ('a, 'a) tval flush_of_meth : meth -> int -> int -> ('a, 'a) t -> ('a, 'a) tval flush : int -> int -> ('a, 'a) t -> ('a, 'a) tval used_out : ('a, 'a) t -> int