izveigor commented on code in PR #6936:
URL: https://github.com/apache/arrow-datafusion/pull/6936#discussion_r1279767925
##########
datafusion/physical-expr/src/array_expressions.rs:
##########
@@ -363,6 +363,177 @@ pub fn make_array(arrays: &[ArrayRef]) ->
Result<ArrayRef> {
}
}
+fn return_empty(return_null: bool, data_type: DataType) -> Arc<dyn Array> {
+ if return_null {
+ new_null_array(&data_type, 1)
+ } else {
+ new_empty_array(&data_type)
+ }
+}
+
+macro_rules! list_slice {
+ ($ARRAY:expr, $I:expr, $J:expr, $RETURN_ELEMENT:expr, $ARRAY_TYPE:ident)
=> {{
+ let array = $ARRAY.as_any().downcast_ref::<$ARRAY_TYPE>().unwrap();
+ if $I == 0 && $J == 0 || $ARRAY.is_empty() {
+ return return_empty($RETURN_ELEMENT, $ARRAY.data_type().clone());
+ }
+
+ let i = if $I < 0 {
+ if $I.abs() as usize > array.len() {
+ return return_empty(true, $ARRAY.data_type().clone());
+ }
+
+ (array.len() as i64 + $I + 1) as usize
+ } else {
+ if $I == 0 {
+ 1
+ } else {
+ $I as usize
+ }
+ };
+ let j = if $J < 0 {
+ if $J.abs() as usize > array.len() {
+ return return_empty(true, $ARRAY.data_type().clone());
+ }
+
+ if $RETURN_ELEMENT {
+ (array.len() as i64 + $J + 1) as usize
+ } else {
+ (array.len() as i64 + $J) as usize
+ }
+ } else {
+ if $J == 0 {
+ 1
+ } else {
+ if $J as usize > array.len() {
+ array.len()
+ } else {
+ $J as usize
+ }
+ }
+ };
+
+ if i > j || i as usize > $ARRAY.len() {
+ return_empty($RETURN_ELEMENT, $ARRAY.data_type().clone())
+ } else {
+ Arc::new(array.slice((i - 1), (j + 1 - i)))
+ }
+ }};
+}
+
+macro_rules! slice {
Review Comment:
I don't quite comprehend your comment. If I use `take` kernel with
`ListArray`, the program returns me the elements of `ListArray` (i. e. `Array`
instances). So if it's really worth it can you give me more information how
should I take data?
Example:
```
use arrow::array::*;
use arrow::compute::take;
use arrow::datatypes::Int32Type;
fn main() {
let data = vec![
Some(vec![Some(0), Some(1), Some(2)]),
None,
Some(vec![Some(3), None, Some(5)]),
Some(vec![Some(6), Some(7)]),
];
let values = ListArray::from_iter_primitive::<Int32Type, _, _>(data);
let indices = UInt32Array::from(vec![0, 3]);
let taken = take(&values, &indices, None).unwrap();
let taken: &GenericListArray<i32> = taken.as_list();
let data = vec![
Some(vec![Some(0), Some(1), Some(2)]),
Some(vec![Some(6), Some(7)]),
];
let expected = ListArray::from_iter_primitive::<Int32Type, _, _>(data);
assert_eq!(expected, taken.clone());
}
```
--
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: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
