risingwave_expr_impl/scalar/
array_replace.rs

1// Copyright 2025 RisingWave Labs
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use risingwave_common::array::{ListRef, ListValue};
16use risingwave_common::types::ScalarRefImpl;
17use risingwave_expr::function;
18
19/// Replaces each array element equal to the second argument with the third argument.
20///
21/// Examples:
22///
23/// ```slt
24/// query T
25/// select array_replace(array[7, null, 8, null], null, 0.5);
26/// ----
27/// {7,0.5,8,0.5}
28///
29/// query T
30/// select array_replace(null, 1, 5);
31/// ----
32/// NULL
33///
34/// query T
35/// select array_replace(null, null, null);
36/// ----
37/// NULL
38///
39/// statement error
40/// select array_replace(array[3, null, 4], true, false);
41///
42/// # Replacing `int` in multidimensional array is not supported yet. (OK in PostgreSQL)
43/// statement error
44/// select array_replace(array[array[array[0, 1], array[2, 3]], array[array[4, 5], array[6, 7]]], 3, 9);
45///
46/// # Unlike PostgreSQL, it is okay to replace `int[][]` inside `int[][][]`.
47/// query T
48/// select array_replace(array[array[array[0, 1], array[2, 3]], array[array[4, 5], array[6, 7]]], array[array[4, 5], array[6, 7]], array[array[2, 3], array[4, 5]]);
49/// ----
50/// {{{0,1},{2,3}},{{2,3},{4,5}}}
51///
52/// # Replacing `int[]` inside `int[][][]` is not supported by either PostgreSQL or RisingWave.
53/// # This may or may not be supported later, whichever makes the `int` support above simpler.
54/// statement error
55/// select array_replace(array[array[array[0, 1], array[2, 3]], array[array[4, 5], array[6, 7]]], array[4, 5], array[8, 9]);
56/// ```
57#[function("array_replace(anyarray, any, any) -> anyarray")]
58fn array_replace(
59    array: ListRef<'_>,
60    elem_from: Option<ScalarRefImpl<'_>>,
61    elem_to: Option<ScalarRefImpl<'_>>,
62) -> ListValue {
63    ListValue::from_datum_iter(
64        &array.data_type(),
65        array.iter().map(|val| match val == elem_from {
66            true => elem_to,
67            false => val,
68        }),
69    )
70}
risingwave_expr_impl/scalar/array_replace.rs

risingwave_expr_impl/scalar/
array_replace.rs
