Building a Regex Engine in Fewer Than 40 Lines of Code

Re:Building a Regex Engine in Fewer Than 40 Lines of Code by klibertp on Tuesday December 05, 2017 @05:26AM (#15850948)

In the "Beautiful Code" book there is a chapter, I think from Rob Pike, which presents a bare-bones regex implementation in C. It doesn't implement alternatives or grouping if I remember correctly, but the implementation is breathtakingly beautiful and not any longer than this one.

I think it's the same implementation described here: http://www.cs.princeton.edu/courses/archive/spr09/cos333/bea... (not 100% sure as I lost my copy of Beautiful Code :()

EDIT: I see the author links to the article at the beginning of the post. Still, I missed this on my first reading, so I think posting the link here is still worthwhile. Especially because the translation to JS kind of misses the point - the beauty of the Rob's implementation comes from recursion and pointers and JS lacks the latter.

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Re:Building a Regex Engine in Fewer Than 40 Lines of Code by 13throwaway37 on Tuesday December 05, 2017 @05:54AM (#15851029)

Literally the first sentence in the posted article mentions this:

I stumbled upon an article the other day where Rob Pike implements a rudimentary regular expression engine in c. I converted his code to Javascript and added test specs so that someone can self-guide themselves through the creation of the regex engine. The specs and solution can be found in this GitHub repository.

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Re:Building a Regex Engine in Fewer Than 40 Lines of Code by why-el on Tuesday December 05, 2017 @07:12AM (#15851255)

If you liked that chapter, check out some recent ideas of his here: https://www.youtube.com/watch?v=HxaD_trXwRE.

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