如何在Haskell中输出二维列表？

Question

我想用换行符输出这个2D列表。我尝试了一些方法，但它们似乎没有用。请帮助我感谢

我的代码：

list = [[' ',' ','*',' ',' ',' ',' ',' ',' ','*',' ',' ',' ',' ',' ',' ','*',' ',' '],
        [' ','*',' ','*',' ',' ',' ',' ','*',' ','*',' ',' ',' ',' ','*',' ','*',' '],
        ['*',' ','*',' ','*',' ',' ','*',' ','*',' ','*',' ',' ','*',' ','*',' ','*'],
        ['-','-','-','-','-','-','-','-','-','-','-','-','-','-','-','-','-','-','-'],
        [' ',' ','1',' ',' ',' ',' ',' ',' ','2',' ',' ',' ',' ',' ',' ','3',' ',' ']]

num :: [Int] -> String
num x = case x of
  []   -> []
  x:xs -> list!!x ++ "\n" ++ num xs

我输出我得到：

Prelude-> num [0,1,2,3,4]
"  *      *      *  \n * *    * *    * * \n* * *  * * *  * * *\n-------------------\n  1      2      3  \n"

我想要的输出：

Prelude-> num [0,1,2,3,4]
  *      *      *  
 * *    * *    * * 
* * *  * * *  * * *
-------------------
  1      2      3