move Log2, Log10, Ln to datafusion-functions

[tinfoil-knight]

Which issue does this PR close?

Closes #9868.

Rationale for this change

As part of #9285, log10, log2 & ln functions should be migrated to the datafusion-functions crate.

Sidenote:
Didn't migrate log because some parts (eg: simplifying expressions: see simpl_log, simpl_power) of log & power functions are dependent on each other & IMO these should be migrated together.

What changes are included in this PR?

Extend the make_math_unary_udf to accept a parameter for monotonicity & migrate log10, log2, ln from built-in functions to the datafusion-functions crate.

Are these changes tested?

Covered by existing tests.

Are there any user-facing changes?

No.

[alamb]

Thank you so much @tinfoil-knight -- 🚀

Didn't migrate log because some parts (eg: simplifying expressions: see simpl_log, simpl_power) of log & power functions are dependent on each other & IMO these should be migrated together.

I agree -- thank you, this makes sense

Note I think we can implement simpl_log using ScalarUDFImpl::simplify (for example https://github.com/apache/arrow-datafusion/blob/9d47dcaab85294f517c899464c442f9a4518b6f2/datafusion/functions/src/datetime/current_date.rs#L76-L91)

It might be a fun little PR if you wanted to try

[alamb]

I wonder if we could make a constant or something that would make this easier to read

For example

/// Single monotonic argument
const MONOTONIC_ONE: Option<Vec<bool>> = Some(vec![Some(true)])
const NON_MONOTONIC: Option<Vec<bool>> = None;

And then

Suggested change

	make_math_unary_udf!(Log2Func, LOG2, log2, log2, Some(vec![Some(true)]));
	make_math_unary_udf!(Log2Func, LOG2, log2, log2, MONOTONIC_ONE);

Perhaps as a follow on PR

[tinfoil-knight]

@alamb
I tried this readability fix but Rust doesn't allow allocation (which vec![] needs) in const or static items. Global let is also not allowed.

The compiler suggested this with static:

consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell

We use once_cell in the physical_plan crate but introducing it to datafusion functions just for this doesn't seem right to me.

[alamb]

We use once_cell in the physical_plan crate but introducing it to datafusion functions just for this doesn't seem right to me.

That makes sense to me. We would probably have to throw in a clone() or something

I thought about this and wrote up another API that would be much nicer #9879 (both for this callsite and montonicity in general)

[tinfoil-knight]

Note I think we can implement simpl_log using ScalarUDFImpl::simplify

Yeah. I'll try this out.

Edit:
I've opened #9875 to track the migration for Power & Log.