triangle function

KairoState Function() triangle(ReactiveFramework framework)

Implementation

KairoState Function() triangle(ReactiveFramework framework) {
  const width = 10;
  return framework.withBuild(() {
    final head = framework.signal(0);
    var current = head as ISignal<int>;
    final list = <ISignal<int>>[];

    for (int i = 0; i < width; i++) {
      final c = current;
      list.add(current);
      current = framework.computed(() {
        return c.read() + 1;
      });
    }

    final sum = framework.computed(() {
      return list.map((x) => x.read()).reduce((a, b) => a + b);
    });

    final callCounter = Counter();
    framework.effect(() {
      sum.read();
      callCounter.count++;
    });

    return () {
      KairoState state = KairoState.success;
      final constant = _count(width);
      framework.withBatch(() {
        head.write(1);
      });

      if (sum.read() != constant) {
        state = KairoState.fail;
      }

      callCounter.count = 0;
      for (int i = 0; i < 100; i++) {
        framework.withBatch(() {
          head.write(i);
        });

        if (sum.read() != constant - width + i * width) {
          state = KairoState.fail;
        }
      }

      if (callCounter.count != 100) {
        return KairoState.fail;
      }

      return state;
    };
  });
}