Change abstract class to trait

Signed-off-by: Nghia Truong <[email protected]>

sql-plugin/src/main/scala/org/apache/spark/sql/rapids/datetimeExpressions.scala

@@ -1525,13 +1525,7 @@ case class GpuLastDay(startDate: Expression)
     input.getBase.lastDayOfMonth()
 }
 
-abstract class GpuTruncDateTime(datetime: Expression, format: Expression)
-    extends GpuBinaryExpression with ImplicitCastInputTypes {
-
-  // We always store date/time to the left and format to the right expressions.
-  override def left: Expression = datetime
-  override def right: Expression = format
-
+trait GpuTruncDateTime extends GpuBinaryExpression with ImplicitCastInputTypes {
   override def doColumnar(lhs: GpuColumnVector, rhs: GpuColumnVector): ColumnVector = {
     DateTimeUtils.truncate(lhs.getBase, rhs.getBase)
   }
@@ -1561,8 +1555,11 @@ abstract class GpuTruncDateTime(datetime: Expression, format: Expression)
   }
 }
 
-case class GpuTruncDate(date: Expression, format: Expression)
-  extends GpuTruncDateTime(date, format) {
+case class GpuTruncDate(date: Expression, format: Expression) extends GpuTruncDateTime {
+  // We always store date/time to the left and format to the right expressions.
+  // This is to make sure `doColumnar` will call `DateTimeUtils.truncate` with the correct order.
+  override def left: Expression = date
+  override def right: Expression = format
 
   override def inputTypes: Seq[AbstractDataType] = Seq(DateType, StringType)
 
@@ -1571,8 +1568,11 @@ case class GpuTruncDate(date: Expression, format: Expression)
   override def prettyName: String = "trunc"
 }
 
-case class GpuTruncTimestamp(format: Expression, timestamp: Expression)
-  extends GpuTruncDateTime(timestamp, format) {
+case class GpuTruncTimestamp(format: Expression, timestamp: Expression) extends GpuTruncDateTime {
+  // We always store date/time to the left and format to the right expressions.
+  // This is to make sure `doColumnar` will call `DateTimeUtils.truncate` with the correct order.
+  override def left: Expression = timestamp
+  override def right: Expression = format
 
   override def inputTypes: Seq[AbstractDataType] = Seq(StringType, TimestampType)