open Wonka_types;
open Wonka_helpers;

let takeLast = max => curry(source => curry(sink => {
  open Rebel;
  let queue = MutableQueue.make();

  captureTalkback(source, (.signal, talkback) => {
    switch (signal) {
    | Start(_) => talkback(.Pull)
    | Push(x) => {
      let size = MutableQueue.size(queue);
      if (size >= max && max > 0) {
        ignore(MutableQueue.pop(queue));
      };

      MutableQueue.add(queue, x);
      talkback(.Pull);
    }
    | End => makeTrampoline(sink, (.) => MutableQueue.pop(queue))
    }
  });
}));