comphead commented on code in PR #9598:
URL: https://github.com/apache/arrow-datafusion/pull/9598#discussion_r1523507420
##########
datafusion/functions/src/macros.rs:
##########
@@ -146,3 +146,102 @@ macro_rules! downcast_arg {
})?
}};
}
+
+/// Macro to create a unary math UDF.
+///
+/// A unary math function takes an argument of type Float32 or Float64,
+/// applies a unary floating function to the argument, and returns a value of
the same type.
+///
+/// $UDF: the name of the UDF struct that implements `ScalarUDFImpl`
+/// $GNAME: a singleton instance of the UDF
+/// $NAME: the name of the function
+/// $UNARY_FUNC: the unary function to apply to the argument
+macro_rules! make_math_unary_udf {
+ ($UDF:ident, $GNAME:ident, $NAME:ident, $UNARY_FUNC:ident) => {
+ make_udf_function!($NAME::$UDF, $GNAME, $NAME);
+
+ mod $NAME {
+ use arrow::array::{ArrayRef, Float32Array, Float64Array};
+ use arrow::datatypes::DataType;
+ use datafusion_common::{exec_err, DataFusionError, Result};
+ use datafusion_expr::{ColumnarValue, ScalarUDFImpl, Signature,
Volatility};
+ use std::any::Any;
+ use std::sync::Arc;
+
+ #[derive(Debug)]
+ pub struct $UDF {
+ signature: Signature,
+ }
+
+ impl $UDF {
+ pub fn new() -> Self {
+ use DataType::*;
+ Self {
+ signature: Signature::uniform(
+ 1,
+ vec![Float64, Float32],
+ Volatility::Immutable,
+ ),
+ }
+ }
+ }
+
+ impl ScalarUDFImpl for $UDF {
+ fn as_any(&self) -> &dyn Any {
+ self
+ }
+ fn name(&self) -> &str {
+ stringify!($NAME)
+ }
+
+ fn signature(&self) -> &Signature {
+ &self.signature
+ }
+
+ fn return_type(&self, arg_types: &[DataType]) ->
Result<DataType> {
+ let arg_type = &arg_types[0];
+
+ match arg_type {
+ DataType::Float64 => Ok(DataType::Float64),
Review Comment:
```suggestion
```
--
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: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
