shehabgamin commented on code in PR #15168: URL: https://github.com/apache/datafusion/pull/15168#discussion_r2002067067
########## datafusion/spark/src/function/math/expm1.rs: ########## @@ -0,0 +1,169 @@ +// 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 crate::function::error_utils::{ + invalid_arg_count_exec_err, unsupported_data_type_exec_err, +}; +use arrow::array::{ArrayRef, AsArray}; +use arrow::datatypes::{DataType, Float64Type}; +use datafusion_common::{Result, ScalarValue}; +use datafusion_expr::{ + ColumnarValue, ScalarFunctionArgs, ScalarUDFImpl, Signature, Volatility, +}; +use datafusion_macros::user_doc; +use std::any::Any; +use std::sync::Arc; + +#[user_doc( + doc_section(label = "Spark Math Functions"), + description = "Returns exp(expr) - 1 as a Float64.", + syntax_example = "expm1(expr)", + sql_example = r#"```sql +> select expm1(0); ++--------------------+ +| expm1(0) | ++--------------------+ +| 0.0 | ++--------------------+ +> select expm1(1); ++----------------+ +| expm1(1) | ++----------------+ +| 50 | ++----------------+ +```"#, + argument( + name = "expr", + description = "An expression that evaluates to a numeric." + ) +)] +#[derive(Debug)] +pub struct SparkExpm1 { + signature: Signature, + aliases: Vec<String>, +} + +impl Default for SparkExpm1 { + fn default() -> Self { + Self::new() + } +} + +impl SparkExpm1 { + pub fn new() -> Self { + Self { + signature: Signature::user_defined(Volatility::Immutable), + aliases: vec!["spark_expm1".to_string()], + } + } +} + +impl ScalarUDFImpl for SparkExpm1 { + fn as_any(&self) -> &dyn Any { + self + } + + fn name(&self) -> &str { + "expm1" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn return_type(&self, _arg_types: &[DataType]) -> Result<DataType> { + Ok(DataType::Float64) + } + + fn invoke_with_args(&self, args: ScalarFunctionArgs) -> Result<ColumnarValue> { + if args.args.len() != 1 { + return Err(invalid_arg_count_exec_err("expm1", (1, 1), args.args.len())); + } + match &args.args[0] { + ColumnarValue::Scalar(ScalarValue::Float64(value)) => Ok( + ColumnarValue::Scalar(ScalarValue::Float64(value.map(|x| x.exp_m1()))), + ), + ColumnarValue::Array(array) => match array.data_type() { + DataType::Float64 => Ok(ColumnarValue::Array(Arc::new( + array + .as_primitive::<Float64Type>() + .unary::<_, Float64Type>(|x| x.exp_m1()), + ) + as ArrayRef)), + other => Err(unsupported_data_type_exec_err( + "expm1", + format!("{}", DataType::Float64).as_str(), + other, + )), + }, + other => Err(unsupported_data_type_exec_err( + "expm1", + format!("{}", DataType::Float64).as_str(), + &other.data_type(), + )), + } + } + + fn aliases(&self) -> &[String] { + &self.aliases + } + + fn coerce_types(&self, arg_types: &[DataType]) -> Result<Vec<DataType>> { + if arg_types.len() != 1 { + return Err(invalid_arg_count_exec_err("expm1", (1, 1), arg_types.len())); + } + if arg_types[0].is_numeric() { + Ok(vec![DataType::Float64]) + } else { + Err(unsupported_data_type_exec_err( + "expm1", + "Numeric Type", + &arg_types[0], + )) + } + } +} + +#[cfg(test)] +mod tests { + use crate::function::math::expm1::SparkExpm1; + use crate::function::utils::test::test_scalar_function; + use arrow::array::{Array, Float64Array}; + use arrow::datatypes::DataType::Float64; + use datafusion_common::{Result, ScalarValue}; + use datafusion_expr::{ColumnarValue, ScalarUDFImpl}; + + macro_rules! test_expm1_float64_invoke { + ($INPUT:expr, $EXPECTED:expr) => { + test_scalar_function!( + SparkExpm1::new(), + vec![ColumnarValue::Scalar(ScalarValue::Float64($INPUT))], + $EXPECTED, + f64, + Float64, + Float64Array + ); + }; + } + + #[test] Review Comment: @andygrove and I found some correctness issues with sqllogictests. Specifically, we found issues with testing the correctness of floating point results. The idea was to do something like this: https://github.com/apache/datafusion/pull/15168#discussion_r1995461595 @alamb What are your thoughts on this? Should we perhaps use sqllogictest as long as we're not testing float point results and as long as the function being tested is not configurable? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
