RE2 VS Cppcheck

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

I dedicated Sunday morning to going over the documentation of the linters we use in the project. The goal was to understand all options and use them in the best way for our project. Seeing their manuals side by side was nice because even very similar things are solved differently. Cppcheck is the most configurable and best documented; JSON Lint lies at the other end.

Using infer, someone else exploited null-dereference checks to introduce simple affine types in C++. Cppcheck also checks for null-dereferences. Unfortunately, that approach means that borrow-counting references have a larger sizeof than non-borrow counting references, so optimizing the count away potentially changes the semantics of a program which introduces a whole new way of writing subtly wrong code.

Also check out (cppcheck)[https://github.com/danmar/cppcheck] if you want more static analysis

My browser refuses to open that link. This is better: https://github.com/danmar/cppcheck

cppcheck - Extensible C/C++ static analyzer focused on finding bugs.

and five C/C++ static code analyzers: * clang-tidy * oclint * cppcheck * cpplint (recently added!) * include-what-you-use (recently added!)

Start by feeding your codebase to a static analysis tool like cppcheck, to rule out obvious bound-checking mistakes in it.

Cppcheck is free. I've previously used it with a C++ project.