List 在Haskell new中打印列表

对haskell来说是全新的，我需要打印出包含在每个单独项目的单独一行中的数据

不确定如何

type ItemDescr = String
type ItemYear = Int
type ItemPrice = Int
type ItemSold = Int
type ItemSales = Int
type Item = (ItemRegion,ItemDescr,ItemYear,ItemPrice,ItemSold,ItemSales)
type ListItems = [Item]

rownumber x
 | x == 1  = ("Scotland","Desktop",2017,900,25,22500)
 | x == 2  = ("England","Laptop",2017,1100,75,82500)
 | x == 3  = ("Wales","Printer",2017,120,15,1800)
 | x == 4  = ("England","Printer",2017,120,60,7200)
 | x == 5  = ("England","Desktop",2017,900,50,45000)
 | x == 6  = ("Wales","Desktop",2017,900,20,18000)
 | x == 7  = ("Scotland","Printer",2017,25,25,3000)

showall
--print??

例如，在每一行上 展示

“苏格兰”，“桌面”，2017900,2522500

---

然后是下一条记录

提示1:

像这样存储数据

items = [("Scotland","Desktop",2017,900,25,22500),
         ("England","Laptop",2017,1100,75,82500),
         ("Wales","Printer",2017,120,15,1800),
         ("England","Printer",2017,120,60,7200),
         ("England","Desktop",2017,900,50,45000),
         ("Wales","Desktop",2017,900,20,18000),
         ("Scotland","Printer",2017,25,25,3000)]

提示2:

实现这个功能

toString :: Item -> String
toString = undefined -- do this yourselves

技巧3:

尝试组合以下功能

• 取消线

  ，已在序曲中

• toString

  ，您刚刚编写了它

• 地图

  ，不需要任何解释

• putStrLn

  ，甚至不确定这是否是一个真正的函数，但您仍然需要它

• （$）

  ，你可以不用这个，但它会给你加分

---

似乎是一个家庭作业问题，在24小时内有人问了一个类似代码风格的问题@Elmex80s它肯定与家庭作业有关，但它不是重复的，它询问的是另一件事。与家庭作业相关的问题本身并没有在SO上被禁止。至于提问者：到目前为止你做了哪些尝试？你知道怎么打印其他东西吗？