GH-44615: [C++][Compute] Add extract_regex_span function

[andishgar]

Rationale for this change

While the extract_regex function returns substrings of the matching regex captures, extract_regex_span returns (index, length) pairs of these substrings relative to the original string values.

Are these changes tested?

Yes, by dedicated unit tests.

Are there any user-facing changes?

No, except a new compute function.

• GitHub Issue: [C++] Add possibility to extract spans/byte offsets directly for compute.extract_regex #44615

[andishgar]

@pitrou could you review this issue?

[mapleFU]

Would the compute document also need to add this?

[andishgar]

Would the compute document also need to add this?

Yes, this is a new compute function called extract_regex_span. Should I add changes somewhere?

[pitrou]

Thanks for this @arashandishgar . There are a number of things to improve in this PR even though the overall implementation is sound, see comments below.

[andishgar]

Appreciate your feedback! I’ll look into it and follow up soon.

[andishgar]

@pitrou I've applied all changes that you suggest. Could You review again?

[pitrou]

Thanks for the update. Here are some more comments.

Also, can you add some documentation to https://github.com/apache/arrow/blob/main/docs/source/cpp/compute.rst#string-component-extraction?

[andishgar]

Thanks for your review, I'll look into it

[andishgar]

Thanks for the update. Here are some more comments.

Also, can you add some documentation to https://github.com/apache/arrow/blob/main/docs/source/cpp/compute.rst#string-component-extraction?

Thanks for mentioning it; I wrote the relevant documentation.

[pitrou]

Thanks for the update @arashandishgar . Here are a couple more comments, can you take a look and address them?

[andishgar]

Thanks for your comment. I will look into it

[pitrou]

I've made some minor changes and added Python bindings. I'll merge this PR if CI is green, thank you @arashandishgar !

[pitrou]

@github-actions crossbow submit -g cpp

[github-actions]

Revision: 703a5ac

Submitted crossbow builds: ursacomputing/crossbow @ actions-4358c6f365

Task	Status
example-cpp-minimal-build-static
example-cpp-minimal-build-static-system-dependency
example-cpp-tutorial
test-alpine-linux-cpp
test-build-cpp-fuzz
test-conda-cpp
test-conda-cpp-meson
test-conda-cpp-valgrind
test-cuda-cpp-ubuntu-22.04-cuda-11.7.1
test-debian-12-cpp-amd64
test-debian-12-cpp-i386
test-fedora-39-cpp
test-ubuntu-22.04-cpp
test-ubuntu-22.04-cpp-20
test-ubuntu-22.04-cpp-bundled
test-ubuntu-22.04-cpp-emscripten
test-ubuntu-22.04-cpp-no-threading
test-ubuntu-24.04-cpp
test-ubuntu-24.04-cpp-bundled-offline
test-ubuntu-24.04-cpp-gcc-13-bundled
test-ubuntu-24.04-cpp-gcc-14
test-ubuntu-24.04-cpp-minimal-with-formats
test-ubuntu-24.04-cpp-thread-sanitizer

[andishgar]

I've made some minor changes and added Python bindings. I'll merge this PR if CI is green, thank you @arashandishgar !

I wanted to take a moment to sincerely thank you for your patience and constructive feedback during the code review process. As this was my first experience contributing to Apache Arrow, I learned a lot throughout the review, and your thoughtful suggestions were extremely valuable.

I realized that I made a mistake by not properly generalizing your suggestion across the entire codebase, especially in my second commit. In my rush to submit the pull request, I overlooked that point.

I truly appreciate your understanding, and I hope to be more diligent in applying feedback consistently in future contributions.

Thanks again for your time and support.

[pitrou]

You're welcome, @arashandishgar . Feel free to contribute again!

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 4 benchmarking runs that have been run so far on merge-commit 0494115.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 4 possible false positives for unstable benchmarks that are known to sometimes produce them.