I love regular expression derivatives. One neat thing about regular expression derivatives is they are continuation-passing style for regular expressions. The derivative is "what to do next" after seeing a character, which is the continuation of the re. It's a nice conceptual connection if you're into programming language theory.

Low-key hate the lack of capitalization on the blog, which made me stumble over every sentence start. Great blog post a bit marred by unnecessary divergence from standard written English.