[functor / Maybe](%E7%AC%AC%E5%85%AB%E7%AB%A0%E7%89%B9%E7%99%BE%E6%83%A0/functor-Maybe.md) [纯错误处理](%E7%AC%AC%E5%85%AB%E7%AB%A0%E7%89%B9%E7%99%BE%E6%83%A0/%E7%BA%AF%E9%94%99%E8%AF%AF%E5%A4%84%E7%90%86.md) [包裹函数 - IO](%E7%AC%AC%E5%85%AB%E7%AB%A0%E7%89%B9%E7%99%BE%E6%83%A0/%E5%8C%85%E8%A3%B9%E5%87%BD%E6%95%B0.md) [异步任务](%E7%AC%AC%E5%85%AB%E7%AB%A0%E7%89%B9%E7%99%BE%E6%83%A0/%E5%BC%82%E6%AD%A5%E4%BB%BB%E5%8A%A1.md) [练习](%E7%AC%AC%E5%85%AB%E7%AB%A0%E7%89%B9%E7%99%BE%E6%83%A0/%E5%AE%9E%E4%BE%8B.md)