refactor: simplify the make_udf_function macro (apache#13712)

Author: jonahgao

datafusion/functions/src/core/mod.rs

@@ -35,17 +35,17 @@ pub mod r#struct;
 pub mod version;
 
 // create UDFs
-make_udf_function!(arrow_cast::ArrowCastFunc, ARROW_CAST, arrow_cast);
-make_udf_function!(nullif::NullIfFunc, NULLIF, nullif);
-make_udf_function!(nvl::NVLFunc, NVL, nvl);
-make_udf_function!(nvl2::NVL2Func, NVL2, nvl2);
-make_udf_function!(arrowtypeof::ArrowTypeOfFunc, ARROWTYPEOF, arrow_typeof);
-make_udf_function!(r#struct::StructFunc, STRUCT, r#struct);
-make_udf_function!(named_struct::NamedStructFunc, NAMED_STRUCT, named_struct);
-make_udf_function!(getfield::GetFieldFunc, GET_FIELD, get_field);
-make_udf_function!(coalesce::CoalesceFunc, COALESCE, coalesce);
-make_udf_function!(greatest::GreatestFunc, GREATEST, greatest);
-make_udf_function!(version::VersionFunc, VERSION, version);
+make_udf_function!(arrow_cast::ArrowCastFunc, arrow_cast);
+make_udf_function!(nullif::NullIfFunc, nullif);
+make_udf_function!(nvl::NVLFunc, nvl);
+make_udf_function!(nvl2::NVL2Func, nvl2);
+make_udf_function!(arrowtypeof::ArrowTypeOfFunc, arrow_typeof);
+make_udf_function!(r#struct::StructFunc, r#struct);
+make_udf_function!(named_struct::NamedStructFunc, named_struct);
+make_udf_function!(getfield::GetFieldFunc, get_field);
+make_udf_function!(coalesce::CoalesceFunc, coalesce);
+make_udf_function!(greatest::GreatestFunc, greatest);
+make_udf_function!(version::VersionFunc, version);
 
 pub mod expr_fn {
     use datafusion_expr::{Expr, Literal};

datafusion/functions/src/crypto/mod.rs

@@ -27,12 +27,12 @@ pub mod sha224;
 pub mod sha256;
 pub mod sha384;
 pub mod sha512;
-make_udf_function!(digest::DigestFunc, DIGEST, digest);
-make_udf_function!(md5::Md5Func, MD5, md5);
-make_udf_function!(sha224::SHA224Func, SHA224, sha224);
-make_udf_function!(sha256::SHA256Func, SHA256, sha256);
-make_udf_function!(sha384::SHA384Func, SHA384, sha384);
-make_udf_function!(sha512::SHA512Func, SHA512, sha512);
+make_udf_function!(digest::DigestFunc, digest);
+make_udf_function!(md5::Md5Func, md5);
+make_udf_function!(sha224::SHA224Func, sha224);
+make_udf_function!(sha256::SHA256Func, sha256);
+make_udf_function!(sha384::SHA384Func, sha384);
+make_udf_function!(sha512::SHA512Func, sha512);
 
 pub mod expr_fn {
     export_functions!((

datafusion/functions/src/datetime/mod.rs

@@ -37,43 +37,23 @@ pub mod to_timestamp;
 pub mod to_unixtime;
 
 // create UDFs
-make_udf_function!(current_date::CurrentDateFunc, CURRENT_DATE, current_date);
-make_udf_function!(current_time::CurrentTimeFunc, CURRENT_TIME, current_time);
-make_udf_function!(date_bin::DateBinFunc, DATE_BIN, date_bin);
-make_udf_function!(date_part::DatePartFunc, DATE_PART, date_part);
-make_udf_function!(date_trunc::DateTruncFunc, DATE_TRUNC, date_trunc);
-make_udf_function!(make_date::MakeDateFunc, MAKE_DATE, make_date);
-make_udf_function!(
-    from_unixtime::FromUnixtimeFunc,
-    FROM_UNIXTIME,
-    from_unixtime
-);
-make_udf_function!(now::NowFunc, NOW, now);
-make_udf_function!(to_char::ToCharFunc, TO_CHAR, to_char);
-make_udf_function!(to_date::ToDateFunc, TO_DATE, to_date);
-make_udf_function!(to_local_time::ToLocalTimeFunc, TO_LOCAL_TIME, to_local_time);
-make_udf_function!(to_unixtime::ToUnixtimeFunc, TO_UNIXTIME, to_unixtime);
-make_udf_function!(to_timestamp::ToTimestampFunc, TO_TIMESTAMP, to_timestamp);
-make_udf_function!(
-    to_timestamp::ToTimestampSecondsFunc,
-    TO_TIMESTAMP_SECONDS,
-    to_timestamp_seconds
-);
-make_udf_function!(
-    to_timestamp::ToTimestampMillisFunc,
-    TO_TIMESTAMP_MILLIS,
-    to_timestamp_millis
-);
-make_udf_function!(
-    to_timestamp::ToTimestampMicrosFunc,
-    TO_TIMESTAMP_MICROS,
-    to_timestamp_micros
-);
-make_udf_function!(
-    to_timestamp::ToTimestampNanosFunc,
-    TO_TIMESTAMP_NANOS,
-    to_timestamp_nanos
-);
+make_udf_function!(current_date::CurrentDateFunc, current_date);
+make_udf_function!(current_time::CurrentTimeFunc, current_time);
+make_udf_function!(date_bin::DateBinFunc, date_bin);
+make_udf_function!(date_part::DatePartFunc, date_part);
+make_udf_function!(date_trunc::DateTruncFunc, date_trunc);
+make_udf_function!(make_date::MakeDateFunc, make_date);
+make_udf_function!(from_unixtime::FromUnixtimeFunc, from_unixtime);
+make_udf_function!(now::NowFunc, now);
+make_udf_function!(to_char::ToCharFunc, to_char);
+make_udf_function!(to_date::ToDateFunc, to_date);
+make_udf_function!(to_local_time::ToLocalTimeFunc, to_local_time);
+make_udf_function!(to_unixtime::ToUnixtimeFunc, to_unixtime);
+make_udf_function!(to_timestamp::ToTimestampFunc, to_timestamp);
+make_udf_function!(to_timestamp::ToTimestampSecondsFunc, to_timestamp_seconds);
+make_udf_function!(to_timestamp::ToTimestampMillisFunc, to_timestamp_millis);
+make_udf_function!(to_timestamp::ToTimestampMicrosFunc, to_timestamp_micros);
+make_udf_function!(to_timestamp::ToTimestampNanosFunc, to_timestamp_nanos);
 
 // we cannot currently use the export_functions macro since it doesn't handle
 // functions with varargs currently

datafusion/functions/src/encoding/mod.rs

@@ -21,8 +21,8 @@ use std::sync::Arc;
 pub mod inner;
 
 // create `encode` and `decode` UDFs
-make_udf_function!(inner::EncodeFunc, ENCODE, encode);
-make_udf_function!(inner::DecodeFunc, DECODE, decode);
+make_udf_function!(inner::EncodeFunc, encode);
+make_udf_function!(inner::DecodeFunc, decode);
 
 // Export the functions out of this package, both as expr_fn as well as a list of functions
 pub mod expr_fn {

datafusion/functions/src/macros.rs

@@ -65,24 +65,23 @@ macro_rules! export_functions {
     };
 }
 
-/// Creates a singleton `ScalarUDF` of the `$UDF` function named `$GNAME` and a
-/// function named `$NAME` which returns that singleton.
+/// Creates a singleton `ScalarUDF` of the `$UDF` function and a function
+/// named `$NAME` which returns that singleton.
 ///
 /// This is used to ensure creating the list of `ScalarUDF` only happens once.
 macro_rules! make_udf_function {
-    ($UDF:ty, $GNAME:ident, $NAME:ident) => {
-        #[doc = "Return a [`ScalarUDF`](datafusion_expr::ScalarUDF) implementation "]
-        #[doc = stringify!($UDF)]
+    ($UDF:ty, $NAME:ident) => {
+        #[doc = concat!("Return a [`ScalarUDF`](datafusion_expr::ScalarUDF) implementation of ", stringify!($NAME))]
         pub fn $NAME() -> std::sync::Arc<datafusion_expr::ScalarUDF> {
             // Singleton instance of the function
-            static $GNAME: std::sync::LazyLock<
+            static INSTANCE: std::sync::LazyLock<
                 std::sync::Arc<datafusion_expr::ScalarUDF>,
             > = std::sync::LazyLock::new(|| {
                 std::sync::Arc::new(datafusion_expr::ScalarUDF::new_from_impl(
                     <$UDF>::new(),
                 ))
             });
-            std::sync::Arc::clone(&$GNAME)
+            std::sync::Arc::clone(&INSTANCE)
         }
     };
 }
@@ -134,13 +133,13 @@ macro_rules! downcast_arg {
 /// 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
 /// $OUTPUT_ORDERING: the output ordering calculation method of the function
+/// $GET_DOC: the function to get the documentation of the UDF
 macro_rules! make_math_unary_udf {
-    ($UDF:ident, $GNAME:ident, $NAME:ident, $UNARY_FUNC:ident, $OUTPUT_ORDERING:expr, $EVALUATE_BOUNDS:expr, $GET_DOC:expr) => {
-        make_udf_function!($NAME::$UDF, $GNAME, $NAME);
+    ($UDF:ident, $NAME:ident, $UNARY_FUNC:ident, $OUTPUT_ORDERING:expr, $EVALUATE_BOUNDS:expr, $GET_DOC:expr) => {
+        make_udf_function!($NAME::$UDF, $NAME);
 
         mod $NAME {
             use std::any::Any;
@@ -248,13 +247,13 @@ macro_rules! make_math_unary_udf {
 /// applies a binary 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
 /// $BINARY_FUNC: the binary function to apply to the argument
 /// $OUTPUT_ORDERING: the output ordering calculation method of the function
+/// $GET_DOC: the function to get the documentation of the UDF
 macro_rules! make_math_binary_udf {
-    ($UDF:ident, $GNAME:ident, $NAME:ident, $BINARY_FUNC:ident, $OUTPUT_ORDERING:expr, $GET_DOC:expr) => {
-        make_udf_function!($NAME::$UDF, $GNAME, $NAME);
+    ($UDF:ident, $NAME:ident, $BINARY_FUNC:ident, $OUTPUT_ORDERING:expr, $GET_DOC:expr) => {
+        make_udf_function!($NAME::$UDF, $NAME);
 
         mod $NAME {
             use std::any::Any;