Gatherers_6.snippet

// Composing gatherers to remove noise
var strings = List.of(5, 5, 5, 1, 5, 5, 5, 1, 5, 5, 1, 5);
Gatherer<Integer, ?, List<Integer>> slide =
        Gatherers.windowSliding(3);
Gatherer<List<Integer>, ?, List<Integer>> smooth =
        Gatherer.of((_, list, downstream) -> {
            int max = list.stream().mapToInt(n -> n).max().orElseThrow();
            list = List.of(max, max, max);
            return downstream.push(list);
        });
Gatherer<List<Integer>, ?, Integer> unslide =
        Gatherer.of((_, list, downStream) -> downStream.push(list.getFirst()));
Gatherer<Integer, ?, Integer> smoothOnASlidingWindow =
        slide.andThen(smooth).andThen(unslide);
var result = strings.stream()
        .gather(smoothOnASlidingWindow)
        .toList();
System.out.println("result = " + result);