Haskell中的`putStrLn`的基本错误。VScode扩展Haskelly

我认为您的代码缩进不足。尝试这个：

main = do line <- getLine
          let line' = reverse line
          putStrLn $ "You said " ++ line' ++ " backwards!"
          putStrLn $ "Yes, you really said " ++ line ++ " backwards!"

具体来说，do应该紧跟在您之后的行与紧随其后的行缩进line <- getLine。

我认为您的代码缩进不足。尝试这个：

main = do line <- getLine
          let line' = reverse line
          putStrLn $ "You said " ++ line' ++ " backwards!"
          putStrLn $ "Yes, you really said " ++ line ++ " backwards!"

具体来说，do应该紧跟在您之后的行与紧随其后的行缩进line <- getLine。