2012-07-01から1ヶ月間の記事一覧
foldlをどう書いたっけな list1 = fromhsl [ 1,2,3,4] val = listfoldr (-) 0 list1 main = putStrLn (show val) data List a = Nil | Cons a (List a) fromhsl [] = Nil fromhsl (x:xs) = Cons x (fromhsl xs) tohsl Nil = [] tohsl (Cons x xs) = x : (toh…