Lua gsub-如何在正则表达式模式中设置最大字符数限制 [英] Lua gsub - How to set max character limit in regex pattern

问题描述

从与此字符串相似的字符串中:

From strings that are similar to this string:

|cff00ccffkey:|r value

我需要除去| cff00ccff和| r才能得到:

I need to remove |cff00ccff and |r to get:

key: value

问题在于|cff00ccff是颜色代码.我知道它总是以|c开头，但是接下来的8个字符可以是任何东西.因此，我需要一个gsub模式来获取|c之后的下8个字符(仅字母数字).

The problem is that |cff00ccff is a color code. I know it always starts with |c but the next 8 characters could be anything. So I need a gsub pattern to get the next 8 characters (alpha-numeric only) after |c.

如何在Lua中做到这一点?我已经尝试过:

How can I do this in Lua? I have tried:

local newString = string.gsub("|cff00ccffkey:|r value", "|c%w*", "")
newString = string.gsub(newString, "|r", "")

但是这将删除所有内容，直到第一个空格，而且我不知道如何指定要选择的最大字符数来避免这种情况.

but that will remove everything up to the first white-space and I don't know how to specify the max characters to select to avoid this.

谢谢.

推荐答案

Lua模式

Lua patterns do not support range/interval/limiting quantifiers.

您可以重复八次%w字母数字模式:

You may repeat %w alphanumeric pattern eight times:

local newString = string.gsub("|cff00ccffkey:|r value", "|c%w%w%w%w%w%w%w%w", "")
newString = string.gsub(newString, "|r", "")
print(newString)
-- => key: value

在线观看 Lua演示.

如果您构建类似('%w'):.rep(8)的模式，也可以使其更具动态性:

You may also make it a bit more dynamic if you build the pattern like ('%w'):.rep(8):

local newString = string.gsub("|cff00ccffkey:|r value", "|c" ..('%w'):rep(8), "")

请参见另一个Lua演示.

如果您的字符串始终遵循此模式-|c<8alpnum_chars><text>|r<value>-您也可以使用类似模式

If your strings always follow this pattern - |c<8alpnum_chars><text>|r<value> - you may also use a pattern like

local newString = string.gsub("|cff00ccffkey:|r value", "^|c" ..('%w'):rep(8) .. "(.-)|r(.*)", "%1%2")

请参见此Lua演示

此处，模式匹配:

• ^-字符串开头
• |c-文字|c
• " ..('%w'):rep(8) .. "-8个字母数字字符
• (.-)-第1组:任意0个以上的字符，数量尽可能少
• |r-一个|r子字符串
• (.*)-第2组:字符串的其余部分.

• ^ - start of string
• |c - a literal |c
• " ..('%w'):rep(8) .. " - 8 alphanumeric chars
• (.-) - Group 1: any 0+ chars, as few as possible
• |r - a |r substring
• (.*) - Group 2: the rest of the string.

%1和%2是指捕获到相应组中的值.

The %1 and %2 refer to the values captured into corresponding groups.

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