Michael-J-Ward commented on issue #10424: URL: https://github.com/apache/datafusion/issues/10424#issuecomment-2105156463
First, I'd like to emphasize that if passing `stride=1` to the UDF worked the same as *not* providing a stride in the SQL api, then this would be just porcelain / a nicety. Reposting the example from: https://github.com/apache/datafusion/issues/10425 ```sql CREATE TEMPORARY VIEW data3 AS VALUES ([1.0, 2.0, 3.0, 3.0]), ([4.0, 5.0, 3.0]), ([6.0]); ❯ select * from data3; +----------------------+ | column1 | +----------------------+ | [1.0, 2.0, 3.0, 3.0] | | [4.0, 5.0, 3.0] | | [6.0] | +----------------------+ ❯ select array_slice(column1, -1, 2) from data3; +-----------------------------------------------+ | array_slice(data3.column1,Int64(-1),Int64(2)) | +-----------------------------------------------+ | [] | | [] | | [6.0] | +-----------------------------------------------+ ❯ select array_slice(column1, -1, 2, 1) from data3; thread 'main' panicked at /Users/andy/.cargo/registry/src/index.crates.io-6f17d22bba15001f/arrow-data-51.0.0/src/transform/primitive.rs:31:43: range end index 9 out of range for slice of length 8 ``` Now to this issue, I agree that I like the explicit arguments versus passing a `Vec`, and I would *hope* the solution doesn't require keeping two separate UDFs. I created a draft with what I would think is the natural rust solution in #10450. I don't know if this violates some datafusion constraint, but all the tests pass. ```rust #[doc = "returns a slice of the array."] pub fn array_slice(array: Expr, begin: Expr, end: Expr, stride: Option<Expr>) -> Expr { if let Some(stride) = stride { Expr::ScalarFunction(ScalarFunction::new_udf( array_slice_udf(), vec![array, begin, end, stride], )) } else { Expr::ScalarFunction(ScalarFunction::new_udf( array_slice_udf(), vec![array, begin, end], )) } } ``` If that is not possible, then a second proposal would be to amend `array_slice_inner` w/ some `null` check. ```rust let stride = if args_len == 4 & is_not_null(&args[3]) { Some(as_int64_array(&args[3])?) } else { None }; ``` But again, this is just a nice-to-have if passing `stride=1` worked the same as *not* providing it in the SQL API. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
