需要变宽的负向后方替换 [英] Need variable width negative lookbehind replacement

问题描述

我在这里查看了许多问题(以及许多其他网站)，并且提供了一些提示，但没有一个给出明确的答案.我知道正则表达式，但我远不是一名专家.这个特定的问题与PHP中的regex有关.

I have looked at many questions here (and many more websites) and some provided hints but none gave me a definitive answer. I know regular expressions but I am far from being a guru. This particular question deals with regex in PHP.

我需要在文本中找到没有被给定类的超链接包围的单词.例如，我可能有

I need to locate words in a text that are not surrounded by a hyperlink of a given class. For example, I might have

This <a href="blabblah" class="no_check">elephant</a> is green and this elephant is blue while this <a href="blahblah">elephant</a> is red.

我需要与第二和第三只大象比赛，而不是第一只(由测试类"no_check"标识).请注意，除了超链接中的href和class外，还有更多的属性.我想出了

I would need to match against the second and third elephants but not the first (identified by test class "no_check"). Note that there could more attributes than just href and class within hyperlinks. I came up with

((?<!<a .*class="no_check".*>)\belephant\b)

在regex测试软件中可以很好地工作，而在PHP中则不能.

which works beautifully in regex test software but not in PHP.

任何帮助将不胜感激.如果您不能提供正则表达式，但是可以找到某种PHP代码逻辑来规避对它的需要，我将不胜感激.

Any help is greatly appreciated. If you cannot provide a regular expression but can find some sort of PHP code logic that would circumvent the need for it, I would be equally grateful.

推荐答案

我最终使用了混合解决方案.事实证明，我必须为特定的关键字解析文本，并检查它们是否已成为链接的一部分，如果没有，则将其添加到超链接中.这里提供的解决方案非常有趣，但不能完全满足我的需求.

I ended up using a mixed solution. It turns out that I had to parse a text for specific keywords and check if they were already part of a link and if not add them to a hyperlink. The solutions provided here were very interesting but not exactly tailored enough for what I needed.

使用HTML解析器的想法虽然不错，但我目前正在另一个项目中使用它.因此，对艾伦·摩尔和埃里克·斯特罗姆提出的解决方案表示敬意.

The idea of using an HTML parser was a good one though and I am currently using one in another project. So hats off to both Alan Moore and Eric Strom for suggesting that solution.

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