module Counter:sig..end
type'at ='a Biocaml_accu.counter
val create : ?n:int -> unit -> 'a t val add : 'a Biocaml_accu.counter -> 'a -> int -> unitval tick : 'a Biocaml_accu.counter -> 'a -> unitval stream : 'a Biocaml_accu.counter -> ('a * int) Stream.tval of_stream : 'a Stream.t -> 'a Biocaml_accu.counter