Github user cloud-fan commented on a diff in the pull request: https://github.com/apache/spark/pull/14033#discussion_r69466495 --- Diff: sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/generators.scala --- @@ -94,6 +94,70 @@ case class UserDefinedGenerator( } /** + * Separate v1, ..., vk into n rows. Each row will have k/n columns. n must be constant. + * {{{ + * SELECT stack(2, 1, 2, 3)) -> + * 1 2 + * 3 NULL + * }}} + */ +@ExpressionDescription( + usage = "_FUNC_(n, v1, ..., vk) - Separate v1, ..., vk into n rows.", + extended = "> SELECT _FUNC_(2, 1, 2, 3);\n [1,2]\n [3,null]") +case class Stack(children: Seq[Expression]) + extends Expression with Generator with CodegenFallback { + + private lazy val numRows = try { + children.head.eval().asInstanceOf[Int] + } catch { + case _: ClassCastException => --- End diff -- I don't think we need to try-catch here, it's guaranteed to be int after the type checking.
--- If your project is set up for it, you can reply to this email and have your reply appear on GitHub as well. If your project does not have this feature enabled and wishes so, or if the feature is enabled but not working, please contact infrastructure at infrastruct...@apache.org or file a JIRA ticket with INFRA. --- --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org