如何只获得tail的第一个成员而不是所有列表?

时间:2019-11-26 03:04:09

标签: haskell

我正在尝试自己实现拖尾功能。我从网上获得了一些帮助,因为我是Haskell的新手,所以我发现了这一点:

tails' :: [a] -> [[a]]
tails' [] = []
tails' (x:xs) = xs : tails' xs

对于tails' [1,2,3],这将返回[[2,3],[3],[]]。我只想获取[2,3]

1 个答案:

答案 0 :(得分:4)

我刚刚完成此操作:

tails' :: [a] -> [a]
tails' [] = error "List is empty"
tails' (x:xs) = xs