Address comments

coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/functions/HiveFunctionResolver.java

@@ -44,7 +44,7 @@
  * Class to resolve hive function names in SQL to Function.
  */
 public class HiveFunctionResolver {
-  private static final String CORAL_VERSIONED_UDF_PREFIX = "coral_udf_version_(\\d+|x)_(\\d+|x)_(\\d+|x)";
+  private static final String CLASS_NAME_PREFIX = "coral_udf_version_(\\d+|x)_(\\d+|x)_(\\d+|x)";
 
   public final FunctionRegistry registry;
   private final ConcurrentHashMap<String, Function> dynamicFunctionRegistry;
@@ -246,14 +246,14 @@ public void addDynamicFunctionToTheRegistry(String funcClassName, Function funct
   /**
    * Removes the versioning prefix from a given UDF class name if it is present.
    * A class name is considered versioned if the prefix before the first dot
-   * follows {@link HiveFunctionResolver#CORAL_VERSIONED_UDF_PREFIX} format
+   * follows {@link HiveFunctionResolver#CLASS_NAME_PREFIX} format
    */
   private String removeVersioningPrefix(String className) {
     if (className != null && !className.isEmpty()) {
       int firstDotIndex = className.indexOf('.');
       if (firstDotIndex != -1) {
         String prefix = className.substring(0, firstDotIndex);
-        if (prefix.matches(CORAL_VERSIONED_UDF_PREFIX)) {
+        if (prefix.matches(CLASS_NAME_PREFIX)) {
           return className.substring(firstDotIndex + 1);
         }
       }

coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/functions/VersionedSqlUserDefinedFunction.java

@@ -58,25 +58,25 @@ public class VersionedSqlUserDefinedFunction extends SqlUserDefinedFunction {
   private final String viewDependentFunctionName;
 
   // The UDF class name value defined in the "functions" property of the view.
-  // i.e. "functions = <viewDependentFunctionName> : <udfClassName>"
-  private final String udfClassName;
+  // i.e. "functions = <viewDependentFunctionName> : <funcClassName>"
+  private final String funcClassName;
 
   private VersionedSqlUserDefinedFunction(SqlIdentifier opName, SqlReturnTypeInference returnTypeInference,
       SqlOperandTypeInference operandTypeInference, SqlOperandTypeChecker operandTypeChecker,
       List<RelDataType> paramTypes, Function function, List<String> ivyDependencies, String viewDependentFunctionName,
-      String udfClassName) {
+      String funcClassName) {
     super(opName, returnTypeInference, operandTypeInference, operandTypeChecker, paramTypes, function,
         SqlFunctionCategory.USER_DEFINED_FUNCTION);
     this.ivyDependencies = ivyDependencies;
     this.viewDependentFunctionName = viewDependentFunctionName;
-    this.udfClassName = udfClassName;
+    this.funcClassName = funcClassName;
   }
 
   public VersionedSqlUserDefinedFunction(SqlUserDefinedFunction sqlUdf, List<String> ivyDependencies,
-      String viewDependentFunctionName, String udfClassName) {
+      String viewDependentFunctionName, String funcClassName) {
     this(new SqlIdentifier(ImmutableList.of(sqlUdf.getName()), SqlParserPos.ZERO), sqlUdf.getReturnTypeInference(),
         null, sqlUdf.getOperandTypeChecker(), sqlUdf.getParamTypes(), sqlUdf.getFunction(), ivyDependencies,
-        viewDependentFunctionName, udfClassName);
+        viewDependentFunctionName, funcClassName);
   }
 
   public List<String> getIvyDependencies() {
@@ -95,6 +95,8 @@ public String getViewDependentFunctionName() {
    * the short function name.
    */
   public String getShortFunctionName() {
+    // getName() returns the unversioned function class, which we use to identify the type inference.
+    // It's just a convention and other naming approaches are valid as long as they identify the type inference.
     String unversionedClassName = getName();
     if (SHORT_FUNC_NAME_MAP.containsKey(unversionedClassName)) {
       return SHORT_FUNC_NAME_MAP.get(unversionedClassName);
@@ -104,8 +106,8 @@ public String getShortFunctionName() {
     return caseConverter.convert(nameSplit[nameSplit.length - 1]);
   }
 
-  public String getUDFClassName() {
-    return udfClassName;
+  public String getFuncClassName() {
+    return funcClassName;
   }
 
   // This method is called during SQL validation. The super-class implementation resets the call's sqlOperator to one
@@ -117,7 +119,7 @@ public String getUDFClassName() {
   public RelDataType deriveType(SqlValidator validator, SqlValidatorScope scope, SqlCall call) {
     RelDataType relDataType = super.deriveType(validator, scope, call);
     ((SqlBasicCall) call).setOperator(new VersionedSqlUserDefinedFunction((SqlUserDefinedFunction) (call.getOperator()),
-        ivyDependencies, viewDependentFunctionName, udfClassName));
+        ivyDependencies, viewDependentFunctionName, funcClassName));
     return relDataType;
   }
 }

coral-hive/src/test/java/com/linkedin/coral/hive/hive2rel/HiveToRelConverterTest.java

@@ -357,7 +357,7 @@ public void testDaliUDFCall() {
   }
 
   @Test
-  public void testUDFWithVersioningClassName() {
+  public void testVersioningUDF() {
     RelNode rel = converter.convertView("test", "tableOneViewShadePrefixUDF");
     String expectedPlan = "LogicalProject(EXPR$0=[com.linkedin.coral.hive.hive2rel.CoralTestUDF($0)])\n"
         + "  LogicalTableScan(table=[[hive, test, tableone]])\n";

coral-spark/src/main/java/com/linkedin/coral/spark/transformers/HiveUDFTransformer.java

@@ -68,7 +68,7 @@ protected SqlCall transform(SqlCall sqlCall) {
     List<URI> listOfUris = dependencies.stream().map(URI::create).collect(Collectors.toList());
     LOG.info("Function: {} is not a Builtin UDF or Transport UDF. We fall back to its Hive "
         + "function with ivy dependency: {}", operatorName, String.join(",", dependencies));
-    final SparkUDFInfo sparkUDFInfo = new SparkUDFInfo(operator.getUDFClassName(), viewDependentFunctionName,
+    final SparkUDFInfo sparkUDFInfo = new SparkUDFInfo(operator.getFuncClassName(), viewDependentFunctionName,
         listOfUris, SparkUDFInfo.UDFTYPE.HIVE_CUSTOM_UDF);
     sparkUDFInfos.add(sparkUDFInfo);
     final SqlOperator convertedFunction =

coral-spark/src/test/java/com/linkedin/coral/spark/CoralSparkTest.java

@@ -167,7 +167,7 @@ public void testHiveUDFTransformer() {
   }
 
   @Test
-  public void testUDFWithVersioningClassName() {
+  public void testVersioningUDF() {
     // After registering unversioned UDF "com.linkedin.coral.hive.hive2rel.CoralTestUDF",
     // Coral should be able to translate the view with the corresponding versioned UDF class
     // "coral_udf_version_0_1_x.com.linkedin.coral.hive.hive2rel.CoralTestUDF"

coral-trino/src/test/java/com/linkedin/coral/trino/rel2trino/HiveToTrinoConverterTest.java

@@ -1003,7 +1003,7 @@ public void testSqlSelectAliasAppenderTransformerWithoutTableAliasPrefix() {
   }
 
   @Test
-  public void testUDFWithVersioningClassName() {
+  public void testVersioningUDF() {
     RelNode relNode = TestUtils.getHiveToRelConverter().convertView("test", "udf_with_versioning_prefix");
     RelToTrinoConverter relToTrinoConverter = TestUtils.getRelToTrinoConverter();
     String expandedSql = relToTrinoConverter.convert(relNode);