{"published":"2014-06-24 00:55:24","blog_url":"https://koba-e964.hatenablog.com/","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fkoba-e964.hatenablog.com%2Fentry%2F2014%2F06%2F24%2F005524\" title=\"\u30e2\u30ca\u30c9\u5909\u63db\u5b50\u306e\u570f\u8ad6\u7684\u7406\u89e3(Categorical understanding of monad transformers) - koba-e964\u306e\u65e5\u8a18\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","width":"100%","author_url":"https://blog.hatena.ne.jp/koba-e964/","author_name":"koba-e964","categories":[],"title":"\u30e2\u30ca\u30c9\u5909\u63db\u5b50\u306e\u570f\u8ad6\u7684\u7406\u89e3(Categorical understanding of monad transformers)","blog_title":"koba-e964\u306e\u65e5\u8a18","provider_url":"https://hatena.blog","url":"https://koba-e964.hatenablog.com/entry/2014/06/24/005524","image_url":null,"type":"rich","version":"1.0","height":"190","description":"\u30e2\u30ca\u30c9\u5909\u63db\u5b50 Haskell\u306b\u304a\u3044\u3066\u30e2\u30ca\u30c9\u5909\u63db\u5b50(Monad transformer)\u306f\u3001\u4ee5\u4e0b\u306e\u6761\u4ef6\u3092\u6e80\u305f\u3059t\u3067\u3059: t\u306ekind\u306f(* -> *) -> * -> * lift :: Monad m => m a -> t m a\u304c\u5b9a\u7fa9\u3055\u308c\u3066\u3044\u308b lift\u304c\u4ee5\u4e0b\u306e\u6cd5\u5247\u3092\u6e80\u305f\u3059: lift . return = return \u2200m k. lift (m >>= k) = lift m >>= (lift . k) (\u3053\u306e\u5b9a\u7fa9\u3092\u4fbf\u5b9c\u4e0a\u51fd\u6570\u7684\u5b9a\u7fa9(functional definition)\u3068\u547c\u3073\u307e\u3059\u3002) \u3053\u306e\u5b9a\u7fa9\u3092\u570f\u8ad6\u306e\u8a00\u8449\u3092\u4f7f\u3063\u3066\u66f8\u304d\u306a\u304a\u3059\u3053\u3068\u3092\u8003\u3048\u308b\u3068\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059: t\u306ekind\u306f\u2026","provider_name":"Hatena Blog"}