Perl正则表达式需求：匹配文本中三个目标字符串的最后出现实例

我需要用支持Perl正则表达式的Doc Parser工具创建文本解析规则，目标是匹配文本中三个指定字符串——i am sitting with after this meeting are、won't be included in your published notes、Single Signal——的最后出现实例。此前在Regex101（PCRE2）中验证有效的表达式，在Doc Parser中无法生效，尝试过添加.*?、+、{1}等变体也没用，现寻求可行的Perl正则解决方案。

示例1 #

Single Signal

Two things I am sitting with after this meeting are...

- Words words words

示例2 #

Single Signal

- words words words

示例3 #

Single Signal

words words that end in won't be included in your published notes.

- words

• 核心表达式：

(?i)(i am sitting with after this meeting are|This is for internal use and won't be included in your published notes|Single Signal)

• 其他变体：添加.*?、+、{1}的调整版本
• 在Regex101生效但Doc Parser失效的表达式：

(?i)[^(i am sitting with after this meeting are|won't be included in your published notes|Single Signal)]+$

方案1：单行模式+贪婪匹配（兼容性最优） #

(?s)(?i).*\b(i am sitting with after this meeting are|won't be included in your published notes|Single Signal)\b

规则说明：

• (?s)：开启单行模式，让.能匹配换行符，适配跨多行的文本结构
• (?i)：忽略大小写，匹配时不区分字母大小写
• .*：贪婪匹配任意字符到文本末尾，确保后续捕获的是最后出现的目标字符串
• \b：单词边界，避免部分匹配（比如防止把包含目标字符串的长单词误识别）

方案2：正向反向断言（需Doc Parser支持） #

如果Doc Parser支持无限长度反向断言，也可使用：

(?i)(?<=.*)(i am sitting with after this meeting are|won't be included in your published notes|Single Signal)

注意：部分Perl正则实现对反向断言的长度有限制，方案1的兼容性更强。

对应三个示例的匹配结果：

• 示例1：捕获i am sitting with after this meeting are
• 示例2：捕获Single Signal
• 示例3：捕获won't be included in your published notes

内容的提问来源于stack exchange，提问作者April Urban