spark-reviews mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From hvanhovell <...@git.apache.org>
Subject [GitHub] spark pull request #14444: [SPARK-16839] [SQL] redundant aliases after clean...
Date Mon, 29 Aug 2016 18:47:02 GMT
Github user hvanhovell commented on a diff in the pull request:

    https://github.com/apache/spark/pull/14444#discussion_r76663726
  
    --- Diff: sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/complexTypeCreator.scala
---
    @@ -172,60 +172,47 @@ case class CreateMap(children: Seq[Expression]) extends Expression
{
     }
     
     /**
    - * Returns a Row containing the evaluation of all children expressions.
    - */
    -@ExpressionDescription(
    -  usage = "_FUNC_(col1, col2, col3, ...) - Creates a struct with the given field values.")
    -case class CreateStruct(children: Seq[Expression]) extends Expression {
    -
    -  override def foldable: Boolean = children.forall(_.foldable)
    -
    -  override lazy val dataType: StructType = {
    -    val fields = children.zipWithIndex.map { case (child, idx) =>
    +* a helper mixin to encapsulate [[CreateStruct]] => [[CreateNamedStruct]] transformation.
    +*/
    +sealed trait CreateStructLikeFactory[T <: Expression] extends (Seq[Expression] =>
T) {
    +  protected case class CretaeStructHelper( children : Seq[Expression] ) {
    +    private def attributeNames: Seq[String] = for {
    +      (child, idx) <- children.zipWithIndex
    +    } yield {
           child match {
    -        case ne: NamedExpression =>
    -          StructField(ne.name, ne.dataType, ne.nullable, ne.metadata)
    -        case _ =>
    -          StructField(s"col${idx + 1}", child.dataType, child.nullable, Metadata.empty)
    +        case ne: NamedExpression => ne.name
    +        case _ => s"col${idx + 1}"
           }
         }
    -    StructType(fields)
    -  }
    -
    -  override def nullable: Boolean = false
    -
    -  override def eval(input: InternalRow): Any = {
    -    InternalRow(children.map(_.eval(input)): _*)
    -  }
     
    -  override def doGenCode(ctx: CodegenContext, ev: ExprCode): ExprCode = {
    -    val rowClass = classOf[GenericInternalRow].getName
    -    val values = ctx.freshName("values")
    -    ctx.addMutableState("Object[]", values, s"this.$values = null;")
    +    private def mkNamedStructArgs: Seq[Expression] = {
    +      for {
    --- End diff --
    
    And if you want to write something that is even shorter (and less understandable):
    ```scala
    attributeNames.map(Literal.apply).zip(children).flatMap(_.productIterator)
    ```


---
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 infrastructure@apache.org or file a JIRA ticket
with INFRA.
---

---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org


Mime
View raw message