BuildYourOwnLisp VS RE2

Build Your Own Lisp

Create your own meta-circular evaluator: https://www.buildyourownlisp.com/

I don't know about C++ but there is this incredible course on C by learning to build your own Lisp. https://www.buildyourownlisp.com/

I find the best way to learn technical topics is to build a simplified version of the thing. The trick is to understand the relationship between the high level components without getting lost in the details. This high level understanding then helps inform you when you drill down into specifics.

I think this book is a shining example of that philosophy: https://www.buildyourownlisp.com/. In the book, you implement an extremely bare-bones version of lisp, but it has been invaluable in my career. I found I was able to understand nuanced language features much more quickly because I have a clear model of how programming languages are decomposed into their components.

If you still want to produce a toy project in C I would suggest to build your own LISP ;-)

If you're after a lisp, MAL on Github (By kanaka) and https://www.buildyourownlisp.com/ are good.

Build your own Lisp is cool but offloads the language grammar and the parsing to the author's mpc library, this is already way overkill for what I'd like to do.

Writing a Lisp - https://www.buildyourownlisp.com/

Lisps are also a good language if you want to know how languages work. They are very easy to make an interpreter for. There are good tutorials for that at https://github.com/kanaka/mal and https://www.buildyourownlisp.com/.

Anyone have any input on:

https://www.buildyourownlisp.com/

It's been in my bookmarks for a long time but I've never really had time to really start it. The "who is this for" page say:

"This book is for anyone wanting to learn C, or who has once wondered how to build their own programming language.".

Well, I'm fairly competent in C (but not great) but would like to get a glimpse of what it's like to build my own language. Is it worth the time?

Looking at the benchmark where C++ is worst compared to other languages, it's depending on the library used. I would guess if they used Google's re2 Regex library instead of Boost's, the result would be different.

https://github.com/google/re2

https://github.com/greensoftwarelab/Energy-Languages/blob/ma...

That page says it just includes "some of the most common special characters", and following the link to the Examples page in turn includes a link to the full list.

Python uses backtracking, so this probably isn't O(n), especially with the ability to choose the dictionary.

But with there are non-backtracking matchers which would make this O(n). Here's re2 from https://github.com/google/re2 :

  >>> import re2

RE2 is a Google regular expression library

google's regex library: https://github.com/google/re2

I am currently working with Regex, specifically Re2, and was wondering if there is a real difference between the above expressions for repeated sub-regex.

I ported Google RE2, a regular expression library, to SPVM as Resource::Re2, and created SPVM::Regex, a wrapper for it.

I searched for I found that there is a Perl compatible regular expression called Google RE2. It is written in C++, and with Google RE2, I can use Perl-compatible regular expressions as a library.

Yes, but there is an interesting clarification here. RE2 has used the "caching" approach documented in the Ruby bug ticket linked for quite some time (since its birth?): https://github.com/google/re2/blob/954656f47fe8fb505d4818da1...

It is mentioned only briefly in Cox's article on regex matching in the wild. Look for the word "bitstate": https://swtch.com/~rsc/regexp/regexp3.html

I didn't know Perl had implemented this trick too.

The paper[1] cited in the Ruby bug ticket was published very recently. When I first read the Ruby bug ticket, I immediately wondered how they sidestepped the memory use problem. The paper's abstract seems to suggest there is some technique for doing so, as it rebuffs the idea of doing "full" memoization. Alas, I do not have access the paper. (Which is fucking ridiculous.)

[1]: https://ieeexplore.ieee.org/abstract/document/9519427