regex - 'two-level regular expressions' 是什么意思？

Question

我理解基本的正则表达式，但不确定下面的引用是什么意思(关于如何实现 wiki 解析器)，谁能提供一些伪代码来启发我？

Two-level regular expressions

This is a very popular approach. It's pretty fast, as it scans the raw text exactly two times.

The idea is to create two kinds of regular expressions -- one to split the text into blocks of different kinds (paragraphs, headings, lists, preformatted blocks, etc.) and then process each of them with different character-level regular expression.

引自: http://www.wikicreole.org/wiki/CommonWikiParsingTechniques

Answer 1

这意味着不是试图在单个 Regex 中完成多个任务，而是将其拆分为两个任务(两个级别)；首先拆分，然后分别处理每个 token 。

我的观点是人们经常不必要地尝试让一个正则表达式一次做太多事情，而不是通过像这样拆分不同的任务来使事情变得更简单。