cloud-fan commented on code in PR #41429: URL: https://github.com/apache/spark/pull/41429#discussion_r1244385979
########## sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/NamedArgumentExpression.scala: ########## @@ -0,0 +1,59 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.spark.sql.catalyst.expressions + +import org.apache.spark.sql.types.DataType + +/** + * This represents an argument expression to a function call accompanied with an + * explicit reference to the corresponding argument name as a string. In this way, + * the analyzer can make sure that the provided values match up to the arguments + * as intended, and the arguments may appear in any order. + * This unary expression is unevaluable because we intend to replace it with + * the provided value itself during query analysis (after possibly rearranging + * the parsed argument list to match up the names to the expected function + * signature). + * + * SQL Syntax: key => value + * SQL grammar: key=identifier FAT_ARROW value=expression + * + * Example usage with the "encode" scalar function: + * SELECT encode("abc", charset => "utf-8"); + * The second argument generates NamedArgumentExpression("charset", Literal("utf-8")) + * SELECT encode(charset => "utf-8", value => "abc"); + * + * @param key The name of the function argument + * @param value The value of the function argument + */ +case class NamedArgumentExpression(key: String, value: Expression) + extends UnaryExpression with Unevaluable { + override def nullable: Boolean = value.nullable Review Comment: nit: we can remove this line as `UnaryExpression` already provides an implementation of `nullable` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
