将字符串重新分配给数组中一组值的列表 [英] Reassigning strings to a set list of values in an array

问题描述

我有一个固定格式的Lua列表(这是来自其他位置的输入).

I have a list in Lua which is fixed format (it's an input from somewhere else).

例如

a = {"apple", "apple 1", "pear", "orange", "orange 3", "kiwi", "tomato"}

我也有一个查找表，我想在其中标准化该集合并将其发送为代码格式.注意:任何包含Apple的东西，例如apple 1，apple 2等，都将被映射为与apple相同的值.

I also have a look up table where I want to normalise this set and send them to a code format. Note: anything containing apple, such as apple 1, apple 2 etc will be mapped to the same value as apple.

例如

"apple" => "RD"
"pear" => "GR"
"orange" => "OG"
"kiwi" => "GR"
"tomato" => "RD"
"banana" => "YL"
etc...

然后我想返回一个包含所有这些替换的列表:

I then want to return a list with all of these substitutions:

fruitBox = {"RD", "GR", "OG"}

我不介意fruitBox是否具有重复的值，最简单的方法是，但它仅在同时在查找和原始列表中表示的情况下才返回值.我一直在尝试这样做，但是要匹配字符串，但是我总是最终陷入如何输出代码的困境.我也尝试过string.gsub并遍历for loop，但仍然没有用处.

I don't mind if fruitBox has repeated values or not, whatever is easiest, but it should only return values if they are represented in both the lookup and the original list. I have been trying to do this but matching the strings, but I always end up getting stuck with how to output the codes. I also tried string.gsub and iterating through a for loop but still got nowhere useful.

推荐答案

您需要将映射列表存储在(哈希表)中，并遍历第一个列表，使用第二个表中的映射更改元素.这样的事情应该起作用:

You need to store the list of mappings in a (hash) table and iterate over the first list changing the elements using the mapping from the second table. Something like this should work:

local a = {"apple", "pear", "orange", "kiwi", "tomato"}
local map = {
  apple = "RD",
  pear = "GR",
  orange = "OG",
  kiwi = "GR",
  tomato = "RD",
  banana = "YL",
}
for index = 1, #a do
  a[index] = map[a[index]] or "missing mapping"
end

-- print results
for index = 1, #a do print(a[index]) end

这会为我打印RD GR OG GR RD.

如果您真的想跳过映射中不存在的元素(我不建议这样做，因为在映射或数据中很难发现错误)，请使用分离表并在循环中执行table.insert而不是a[index]...分配.

If you really want to skip the elements not present in the mapping (which I don't recommend, as it will be difficult to find errors in the mapping or the data), then use a separate table and do table.insert instead of a[index]... assignment in the loop.

如果字符串中包含一些非字母(如更新的问题中所述)，则您可能需要使用gsub("%A","")或类似的方式将其删除.

If the strings have some non-letters (as in the updated question), you may want to remove them using gsub("%A","") or something similar.

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