小编SR2*_*R23的帖子

在下面的代码中,Haskell抱怨

Non-exhaustive patterns in function prime'

prime :: Int -> [Int]
prime x = prime' [2..x] where
  prime' (p:ps)= p : prime' [x | x <- ps, mod x p > 0 && prime'' x [2..div x 2]]     
  prime'' _ [] = True
  prime'' n (x:xs)
    | mod n x == 0 = False
    |    otherwise = prime'' n xs

prime' []=[]

我找不到我的错误.有人可以解释为什么会发生这种情况,这意味着什么？

我应该在Haskell中编写一个小函数,它应该擦除列表中两次的元素.不幸的是,Haskell抱怨"输入错误'|'' ".有人可以帮我吗？

makeSets=mSet[]s
         where 
            mSet stack []=stack
            mSet stack (x:xs)
                             |contains stack x=mSetstack xs
                             | otherwise =mSet (x:stack) xs
                                          where 
                                                contains [] thing=False
                                                contains (x:xs)thing
                                                                     | x==thing=True
                                                                     |otherwise=contains xs thing