Github user twalthr commented on a diff in the pull request:
https://github.com/apache/flink/pull/4488#discussion_r131717969
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/codegen/calls/ScalarOperators.scala
---
@@ -937,15 +935,40 @@ object ScalarOperators {
}
}
- def generateConcat(
- method: Method,
- operands: Seq[GeneratedExpression]): GeneratedExpression = {
+ def generateConcat(operands: Seq[GeneratedExpression]):
GeneratedExpression = {
- generateCallIfArgsNotNull(false, STRING_TYPE_INFO, operands) {
- (terms) =>s"${qualifyMethod(method)}(${terms.mkString(", ")})"
+ generateCallIfArgsNotNull(true, STRING_TYPE_INFO, operands) {
+ (terms)
=>s"${qualifyMethod(BuiltInMethods.CONCAT)}(${terms.mkString(", ")})"
}
}
+ def generateConcatWs(operands: Seq[GeneratedExpression]):
GeneratedExpression = {
+
+ val resultTerm = newName("result")
+ val nullTerm = newName("isNull")
+ val defaultValue = primitiveDefaultValue(Types.STRING)
+
+ val operatorCode =
+ s"""
+ |${operands.map(_.code).mkString("\n")}
+ |
+ |String $resultTerm;
+ |boolean $nullTerm;
+ |if (${operands.head.nullTerm}) {
+ | $nullTerm = true;
+ | $resultTerm = $defaultValue;
+ |} else {
+ |
+ | ${operands.tail.map(o => s"if (${o.nullTerm}) ${o.resultTerm} =
null;").mkString("\n")}
--- End diff --
I would not reassign a `resultTerm`. Actually they should be declared
`final` for optimization. We should do this in the near future.
---
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 [email protected] or file a JIRA ticket
with INFRA.
---
