Wrapping up As the article was quite long, here a summary of the main points: - The “regular expressions” used by programmers have very little in common with t

Wrapping up As the article was quite long, here a summary of the main points: - The “regular expressions” used by programmers have very little in common with the original notion of regularity in the context of formal language theory. - Regular expressions (at least PCRE) can match all context-free languages. As such they can also match well-formed HTML and pretty much all other programming languages. - Regular expressions can match at least some context-sensitive languages. - Matching of regular expressions is NP-complete. As such you can solve any other NP problem using regular expressions. I wish he wrote that in the beginning of the article. Would have saved me a lot of skimming (I already know grammar theory).