-
Notifications
You must be signed in to change notification settings - Fork 978
/
other.rs
57 lines (53 loc) · 2.14 KB
/
other.rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.
use arrow::datatypes::DataType;
use super::binary::comparison_coercion;
/// Attempts to coerce the types of `list_types` to be comparable with the
/// `expr_type`.
/// Returns the common data type for `expr_type` and `list_types`
pub fn get_coerce_type_for_list(
expr_type: &DataType,
list_types: &[DataType],
) -> Option<DataType> {
list_types
.iter()
.fold(Some(expr_type.clone()), |left, right_type| match left {
None => None,
Some(left_type) => comparison_coercion(&left_type, right_type),
})
}
/// Find a common coerceable type for all `then_types` as well
/// and the `else_type`, if specified.
/// Returns the common data type for `then_types` and `else_type`
pub fn get_coerce_type_for_case_when(
then_types: &[DataType],
else_type: Option<&DataType>,
) -> Option<DataType> {
let else_type = match else_type {
None => then_types[0].clone(),
Some(data_type) => data_type.clone(),
};
then_types
.iter()
.fold(Some(else_type), |left, right_type| match left {
// failed to find a valid coercion in a previous iteration
None => None,
// TODO: now just use the `equal` coercion rule for case when. If find the issue, and
// refactor again.
Some(left_type) => comparison_coercion(&left_type, right_type),
})
}