小编Che*_*arl的帖子

我在Mac上,我通过命令行运行Haskell.这是我的代码我递归地反转列表.

import Debug.Trace
reverse1 :: (Show a) => [a] -> [a]  
reverse1 [] = []  
reverse1 (x:xs) = trace(“input xs: “ ++ show xs) $ reverse1 xs ++ [x]

赋值是以递归方式执行,并显示跟踪.如果我在添加跟踪信息后删除跟踪信息,它就会反过来.这是我收到的错误.

[1 of 1] Compiling Main             ( reverse.hs, interpreted )

reverse.hs:4:24: lexical error at character '\8220'
Failed, modules loaded: none.