sirocco https://blog.hatena.ne.jp/sirocco/ sirocco の書いてもすぐに忘れるメモ https://sirocco.hatenadiary.org/ Haskell で Ruby の [a, b, c].join(x) と同等のことをするには intersperse が便利。 > concat $ Data.List.intersperse "-" ["abc", "def", "ghi"] -- > "abc-def-ghi" -- intersperse を自分で作るとこんな感じ。 intersperse' :: a -> [a] -> [a] intersperse' _ [x] = [x] intersperse' s (x:xs) = x:s:intersperse' s xs Haskellの駄目な使い方 / 文字列処言語間理比… 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fsirocco.hatenadiary.org%2Fentry%2F20111010%2F1318278843" title="foldl1,foldr1,scanl1, scanr1 - sirocco の書いてもすぐに忘れるメモ" 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 2011-10-10 05:34:03 rich https://sirocco.hatenadiary.org/entry/20111010/1318278843 1.0 100%