risingwave_expr_impl/table_function/
pg_expandarray.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::types::{DataType, ListRef, ScalarRefImpl, StructType};
16use risingwave_expr::{Result, function};
17
18/// Returns the input array as a set of rows with an index.
19///
20/// ```slt
21/// query II
22/// select * from _pg_expandarray(array[1,2,null]);
23/// ----
24/// 1    1
25/// 2    2
26/// NULL 3
27///
28/// query TI
29/// select * from _pg_expandarray(array['one', null, 'three']);
30/// ----
31/// one   1
32/// NULL  2
33/// three 3
34/// ```
35#[function(
36    "_pg_expandarray(anyarray) -> setof struct<x any, n int4>",
37    type_infer = "infer_type"
38)]
39fn _pg_expandarray(array: ListRef<'_>) -> impl Iterator<Item = (Option<ScalarRefImpl<'_>>, i32)> {
40    #[allow(clippy::disallowed_methods)]
41    array.iter().zip(1..)
42}
43
44fn infer_type(args: &[DataType]) -> Result<DataType> {
45    Ok(DataType::Struct(StructType::new(vec![
46        ("x", args[0].as_list().clone()),
47        ("n", DataType::Int32),
48    ])))
49}
risingwave_expr_impl/table_function/pg_expandarray.rs

risingwave_expr_impl/table_function/
pg_expandarray.rs
