The unary_scalar_expr macro is used on functions that require several arguments

[j-a-m-l]

Describe the bug
The unary_scalar_expr macro is used on functions that require several arguments, so those functions fail always.

To Reproduce

df.select(vec![
    replace(&[col("number"), lit(","), lit(".")])
])

It fails with:

expected enum `Expr`, found `&[Expr; 3]`

Expected behavior
I'd expect that those functions work correctly.

Additional context
That macro also adds this comment: this scalar function is not documented yet.

Proposal
I'd create a new macro for functions that could receive several arguments.
Ideally that macro would reuse the comment of the "real" function, but that would be very involved probably.