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vortex_array/arrays/listview/vtable/
operations.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright the Vortex contributors
3
4use std::sync::Arc;
5
6use vortex_error::VortexResult;
7
8use crate::ExecutionCtx;
9use crate::array::ArrayView;
10use crate::array::OperationsVTable;
11use crate::arrays::ListView;
12use crate::arrays::listview::ListViewArrayExt;
13use crate::scalar::Scalar;
14
15impl OperationsVTable<ListView> for ListView {
16    fn scalar_at(
17        array: ArrayView<'_, ListView>,
18        index: usize,
19        _ctx: &mut ExecutionCtx,
20    ) -> VortexResult<Scalar> {
21        // By the preconditions we know that the list scalar is not null.
22        let list = array.list_elements_at(index)?;
23        let children: Vec<Scalar> = (0..list.len())
24            .map(|i| list.scalar_at(i))
25            .collect::<VortexResult<_>>()?;
26
27        Ok(Scalar::list(
28            Arc::new(list.dtype().clone()),
29            children,
30            array.dtype().nullability(),
31        ))
32    }
33}