
Implementing Regular Expressions (2007) - ScottWRobinson
https://swtch.com/~rsc/regexp/
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aaronbrethorst
I highly recommend Sipser's "Introduction to the Theory of Computation" if you
want to learn more. Here's a link to the edition I had in college (around
2002): [http://www.amazon.com/Introduction-Theory-Computation-
Michae...](http://www.amazon.com/Introduction-Theory-Computation-Michael-
Sipser/dp/0534950973)

It's used at MIT
([http://math.mit.edu/~sipser/18404/](http://math.mit.edu/~sipser/18404/)),
the U of MN (where I used it), and—I'm sure—most other schools.

You can buy the newest edition, but you'll spend an extra $150 for not much
gain.

~~~
roel_v
Off topic for this thread, but still of interest I think: when buying text
books not for college (i.e., when exercise order and page numbering don't
matter), I've saved hundreds over the last years buying international editions
through e.g. Abebooks. Like, the book mentioned in the parent is 6$ (!) with
free shipping (!!!) from India:
[http://www.abebooks.com/servlet/SearchResults?an=sipser&sts=...](http://www.abebooks.com/servlet/SearchResults?an=sipser&sts=t)
.

These are usually either used or new international/Indian editions. The
quality is not as good as the 'real' versions (very thin paper, binding not
very solid) but the savings are substantial. I bought a book a few weeks ago
that I couldn't find for less than 120 euros here in Europe, and it cost me
~20 euros including shipping from India.

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ori_b
A fantastic guide. I stole a lot of the ideas from it when I implemented
regexes for my language.

[http://git.eigenstate.org/ori/mc.git/tree/libregex/](http://git.eigenstate.org/ori/mc.git/tree/libregex/)

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jhallenworld
Can you implement submatch tracking with a DFA? There is this:
[http://stackoverflow.com/questions/3287860/what-is-a-
tagged-...](http://stackoverflow.com/questions/3287860/what-is-a-tagged-dfa)

But when I looked, the code did not use it.

