{"html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fgiarrium.hatenablog.com%2Fentry%2F2021%2F07%2F05%2F212526\" title=\"28\u65e5\u76ee Recursive Enumerations - \u305c\u306e\u305c\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","height":"190","categories":["Swift"],"published":"2021-07-05 21:25:26","provider_url":"https://hatena.blog","width":"100%","provider_name":"Hatena Blog","author_name":"gurrium","version":"1.0","url":"https://giarrium.hatenablog.com/entry/2021/07/05/212526","author_url":"https://blog.hatena.ne.jp/gurrium/","blog_url":"https://giarrium.hatenablog.com/","type":"rich","title":"28\u65e5\u76ee Recursive Enumerations","image_url":null,"description":"\u65e5\u8a18 \u304a\u3084\u3059\u307f \u4eca\u65e5\u66f8\u3044\u305f\u30b3\u30fc\u30c9 indirect enum ArithmeticExpression { case number(Int) case addition(ArithmeticExpression, ArithmeticExpression) case multiplication(ArithmeticExpression, ArithmeticExpression) } func evaluate(_ expression: ArithmeticExpression) -> Int { switch expression { case let .number(value): r\u2026","blog_title":"\u305c\u306e\u305c"}