datafusion_spark/function/math/
expm1.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use crate::function::error_utils::unsupported_data_type_exec_err;
19use arrow::array::{ArrayRef, AsArray};
20use arrow::datatypes::{DataType, Float64Type};
21use datafusion_common::utils::take_function_args;
22use datafusion_common::{Result, ScalarValue};
23use datafusion_expr::{
24    ColumnarValue, ScalarFunctionArgs, ScalarUDFImpl, Signature, Volatility,
25};
26use std::sync::Arc;
27
28/// <https://spark.apache.org/docs/latest/api/sql/index.html#expm1>
29#[derive(Debug, PartialEq, Eq, Hash)]
30pub struct SparkExpm1 {
31    signature: Signature,
32}
33
34impl Default for SparkExpm1 {
35    fn default() -> Self {
36        Self::new()
37    }
38}
39
40impl SparkExpm1 {
41    pub fn new() -> Self {
42        Self {
43            signature: Signature::exact(vec![DataType::Float64], Volatility::Immutable),
44        }
45    }
46}
47
48impl ScalarUDFImpl for SparkExpm1 {
49    fn name(&self) -> &str {
50        "expm1"
51    }
52
53    fn signature(&self) -> &Signature {
54        &self.signature
55    }
56
57    fn return_type(&self, _arg_types: &[DataType]) -> Result<DataType> {
58        Ok(DataType::Float64)
59    }
60
61    fn invoke_with_args(&self, args: ScalarFunctionArgs) -> Result<ColumnarValue> {
62        let [arg] = take_function_args(self.name(), args.args)?;
63        match arg {
64            ColumnarValue::Scalar(ScalarValue::Float64(value)) => Ok(
65                ColumnarValue::Scalar(ScalarValue::Float64(value.map(|x| x.exp_m1()))),
66            ),
67            ColumnarValue::Array(array) => match array.data_type() {
68                DataType::Float64 => Ok(ColumnarValue::Array(Arc::new(
69                    array
70                        .as_primitive::<Float64Type>()
71                        .unary::<_, Float64Type>(|x| x.exp_m1()),
72                )
73                    as ArrayRef)),
74                other => Err(unsupported_data_type_exec_err(
75                    "expm1",
76                    format!("{}", DataType::Float64).as_str(),
77                    other,
78                )),
79            },
80            other => Err(unsupported_data_type_exec_err(
81                "expm1",
82                format!("{}", DataType::Float64).as_str(),
83                &other.data_type(),
84            )),
85        }
86    }
87}
datafusion_spark/function/math/expm1.rs

datafusion_spark/function/math/
expm1.rs
