fix: core_expressions feature flag broken, move overlay into core functions

[shruti2522]

Which issue does this PR close?

• Closes core_expressions feature is broken in the datafusion-functions #15207 .

Rationale for this change

What changes are included in this PR?

deprecate core_expressions fetaure flag and move overlay to core

Are these changes tested?

Are there any user-facing changes?

[alamb]

Thank you @shruti2522 🙏

The only concern I have about this PR is that now overlay() is not listed as a string function, which is kind of strange.

It also means that anyone who usesoverlay in their project would have to change the use path.

I wonder if it would be possible to also have it listed with the string functions (as well as core)) maybe by re-exporting it in datafusion-functions/string somehow 🤔

[shruti2522]

Thank you @shruti2522 🙏

The only concern I have about this PR is that now overlay() is not listed as a string function, which is kind of strange.

It also means that anyone who usesoverlay in their project would have to change the use path.

I wonder if it would be possible to also have it listed with the string functions (as well as core)) maybe by re-exporting it in datafusion-functions/string somehow 🤔

hey @alamb, I have already added a re-export at the end of datafusion/functions/src/string/overlay.rs like this

pub use crate::core::overlay::*;

Maybe, I should remove the deprecation statement for overlay() in string.rs. Should we consider a different approach for this?

[alamb]

hey @alamb, I have already added a re-export at the end of datafusion/functions/src/string/overlay.rs like this

Thanks @shruti2522 - that looks good to me

I double checked and it is appearing as we would expect

Thank you 🙏

[shruti2522]

hey @alamb, I have already added a re-export at the end of datafusion/functions/src/string/overlay.rs like this

Thanks @shruti2522 - that looks good to me

I double checked and it is appearing as we would expect

Thank you 🙏

Do I need to make any further changes in this PR @alamb ?

[alamb]

Sorry @shruti2522 -- I think this one looks good to me. I think I forgot to click approve

[alamb]

I merged up from main and removed a reference in the CI tests to the now removed core_expressions feature

[alamb]

Thanks again @shruti2522