minor updates

Author: danielhumanmod

spark/src/main/scala/org/apache/comet/serde/strings.scala

@@ -309,12 +309,6 @@ object CometRegExpExtract extends CometExpressionSerde[RegExpExtract] {
     expr.idx match {
       case Literal(_, DataTypes.IntegerType) =>
         Compatible()
-      case Literal(_, DataTypes.LongType) =>
-        Compatible()
-      case Literal(_, DataTypes.ShortType) =>
-        Compatible()
-      case Literal(_, DataTypes.ByteType) =>
-        Compatible()
       case _ =>
         Unsupported(Some("Only literal group index is supported"))
     }
@@ -354,12 +348,6 @@ object CometRegExpExtractAll extends CometExpressionSerde[RegExpExtractAll] {
     expr.idx match {
       case Literal(_, DataTypes.IntegerType) =>
         Compatible()
-      case Literal(_, DataTypes.LongType) =>
-        Compatible()
-      case Literal(_, DataTypes.ShortType) =>
-        Compatible()
-      case Literal(_, DataTypes.ByteType) =>
-        Compatible()
       case _ =>
         Unsupported(Some("Only literal group index is supported"))
     }

spark/src/test/scala/org/apache/comet/CometStringExpressionSuite.scala

@@ -409,7 +409,7 @@ class CometStringExpressionSuite extends CometTestBase {
         checkSparkAnswerAndOperator("SELECT regexp_extract(_1, '(\\d+)-(\\d+)', 1) FROM tbl")
         // Test group 2
         checkSparkAnswerAndOperator("SELECT regexp_extract(_1, '(\\d+)-(\\d+)', 2) FROM tbl")
-        // Test non-existent group → should return ""
+        // Test non-existent group → should error
         checkSparkAnswerAndOperator("SELECT regexp_extract(_1, '(\\d+)-(\\d+)', 3) FROM tbl")
         // Test empty pattern
         checkSparkAnswerAndOperator("SELECT regexp_extract(_1, '', 0) FROM tbl")
@@ -617,7 +617,7 @@ class CometStringExpressionSuite extends CometTestBase {
       val data = Seq(("a1b2c3", 1), ("test123", 1), (null, 1))
 
       withParquetTable(data, "tbl") {
-        // Group index out of bounds - should match Spark's behavior (error or empty)
+        // Group index out of bounds - should match Spark's behavior (error)
         // Pattern has only 1 group, asking for group 2
         checkSparkAnswerAndOperator("SELECT regexp_extract_all(_1, '(\\d+)', 2) FROM tbl")