zehnpaard https://blog.hatena.ne.jp/zehnpaard/ Arantium Maestum https://zehnpaard.hatenablog.com/ Haskell Thinking Functionally with Haskell リストに対する処理の性質・法則、Functorに対するの一般化、性質の証明法についてメモ： まずはconcat、map、filterの定義： concat :: [[a]] -> [a] concat [] = [] concat (xs:xss) = xs ++ concat xss map :: (a -> b) -> [a] -> [b] map _ [] = [] map f (x: xs) = f x : map f xs filter :: (a -> Bool) -> [a] -> [a] filter _ [] = [] filter p (x:xs) | p x = x:fi… 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fzehnpaard.hatenablog.com%2Fentry%2F2018%2F03%2F13%2F214540" title="Thinking Functionally with Haskell勉強メモ: 第４章２ concat/map/filter、functorと自然変換、同一性の証明 - Arantium Maestum" class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> Hatena Blog https://hatena.blog 2018-03-13 21:45:40 rich https://zehnpaard.hatenablog.com/entry/2018/03/13/214540 1.0 100%