The type of bounded-size buffers.

create n allocates a ring buffer that can hold up to n values.

• raises [Invalid_argument]

  if n is 0 or less.

capacity b is the number of elements that b can hold.

length b is the number of elements that are currently in b.

total_weight b is the summed weight of all elements that are currently in b.

add b (v, w) adds the value v of weight w to the buffer b. If the buffer b cannot hold this value, i.e., w > capacity b then this value is not added. And, if by adding this value, the buffer would get too full, older values will be dropped until the v fits.

add_and_return_erased b (v, w) has the same effect as add b (v,w) but it also returns the dropped values when applicable (and None otherwise). Dropped values are ordered from the oldest to the most recently inserted

add_list b vs adds each element (with their weight) of the list vs in the order they appear in the list. It returns a list of nodes, for each of the inserted elements. Elements that are too large in vs w.r.t to capacity b are filtered out.

If the total weight of vs is larger than capacity b then a first-fit strategy is used and the last elements in vs are prioritized.

For instance: add_list (create 5) [(x, 1); (y, 3); (z, 4)] will successfully return [x ; z] which are added in the buffer.

clear b removes all values from the buffer b.

fold b ~init ~f folds over the value of the buffer b, newest to oldest.

fold_oldest_first b ~init ~f folds over the value of the buffer b, oldest to newest.

elements b is a list that contains the same elements as the buffer b, oldest first, newest last.

oldest_element b returns the oldest inserted element from the buffer b if any.

newest_element b returns the oldest inserted element from the buffer b if any.

remove_oldest b removes and returns the oldest inserted element from the buffer b or None if the buffer is empty.

remove_newest b removes and returns the most recently inserted element from the buffer b or None if the buffer is empty.