comphead commented on code in PR #20459:
URL: https://github.com/apache/datafusion/pull/20459#discussion_r2836879244
##########
datafusion/common/src/scalar/mod.rs:
##########
@@ -3435,12 +3435,13 @@ impl ScalarValue {
}
fn list_to_array_of_size(arr: &dyn Array, size: usize) -> Result<ArrayRef>
{
- let arrays = repeat_n(arr, size).collect::<Vec<_>>();
- let ret = match !arrays.is_empty() {
- true => arrow::compute::concat(arrays.as_slice())?,
- false => arr.slice(0, 0),
- };
- Ok(ret)
+ if size == 0 {
+ return Ok(arr.slice(0, 0));
+ }
+
+ let n = arr.len() as u32;
+ let indices = UInt32Array::from_iter_values((0..size).flat_map(|_|
0..n));
Review Comment:
perhaps we can document here
```
Suppose inner array is [A, B, C] and you want size=3:
indices becomes: [0,1,2, 0,1,2, 0,1,2]
take produces: [A,B,C, A,B,C, A,B,C]
```
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