Implementation for regex_instr

[nirnayroy]

Which issue does this PR close?

• Closes #13009

Rationale for this change

Implements a regex SQL standard function in datafusion

What changes are included in this PR?

Implementation, tests, benches and docs for the regexp_instr function

Are these changes tested?

Yes

Are there any user-facing changes?

Yes

No

[2010YOUY01]

Thank you. I'm wondering what's the reference system for this function's behavior (like postgres or others)

[nirnayroy]

Thank you. I'm wondering what's the reference system for this function's behavior (like postgres or others)

The reference system for this function's behaviour is postgres.

[alamb]

Thank you for this PR @nirnayroy

Can you please resolve the CI error: https://github.com/apache/datafusion/actions/runs/14820525339/job/41754009017?pr=15928

If you encounter an error, run './dev/update_function_docs.sh' and commit

[nirnayroy]

Thank you for this PR @nirnayroy

Can you please resolve the CI error: https://github.com/apache/datafusion/actions/runs/14820525339/job/41754009017?pr=15928

If you encounter an error, run './dev/update_function_docs.sh' and commit

I ran the bash script, but I’m not sure if the workflow succeeded.

[nirnayroy]

fixed the cippy errors showing up in the workflow

[nirnayroy]

fixed formatting error in workflow

[alamb]

@Omega359 I wonder if you might have time to review this PR?

[Omega359]

Of course @alamb, not sure how I missed this one. It may be a day or two though

[nirnayroy]

Hi @blaginin, thanks for the review and regret the delay in reply. I think I have rectified a majority of the concerns raised. Please have a look again.

[nirnayroy]

Hi @blaginin , thanks for the help and suggestions for improvement. I have addressed the requested changes. Please have another look.

Tests are failing. If that helps, you can run the CI command locally to debug:

I have tried running it and the tests are passing on my local.

[Omega359]

I'll pull this branch later this week and run the tests but in general this PR is looking pretty good! I left a few comments/suggestions for a few things I found from a quick review.

[Omega359]

Run extended tests

[alamb]

Run extended tests

It works!

[Omega359]

Clippy failures related to rand update (I think https://github.com/apache/datafusion/pull/16062)

Edit: looks like the usages of rand for the benchmark was updated in the above commit ... I'm thinking the additions in this PR do not reflect that change.

[Omega359]

Run extended tests

[Omega359]

Run extended tests

[Omega359]

LGTM :) @blaginin

[blaginin]

@nirnayroy thank you so much for your work, i think that's a very useful new function 🎉 welcome to the project!!!

[alamb]

🚀