Github user sunjincheng121 commented on a diff in the pull request:
https://github.com/apache/flink/pull/4138#discussion_r124007599
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/functions/ScalarFunctions.scala
---
@@ -0,0 +1,79 @@
+/*
+ * 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.flink.table.runtime.functions
+
+import scala.annotation.varargs
+import java.math.{BigDecimal => JBigDecimal}
+import java.lang.{StringBuffer => JStringBuffer}
+
+/**
+ * All build-in scalar scalar functions.
+ */
+class ScalarFunctions {}
+
+object ScalarFunctions {
+
+ def power(a: Double, b: JBigDecimal): Double = {
+ Math.pow(a, b.doubleValue())
+ }
+
+ /**
+ * Returns the string that results from concatenating the arguments.
+ * Returns NULL if any argument is NULL.
+ */
+ @varargs
+ def concat(args: String*): String = {
+ val sb = new JStringBuffer
+ var i = 0
+ while (i < args.length) {
+ if (args(i) == null) {
+ return null
+ }
+ sb.append(args(i))
+ i += 1
+ }
+ sb.toString
+ }
+
+ /**
+ * Returns the string that results from concatenating the arguments and
separator.
+ * Returns NULL If the separator is NULL.
+ *
+ * Note: CONCAT_WS() does not skip empty strings. However, it does skip
any NULL values after
+ * the separator argument.
+ *
+ * @param args The first element of argument is the separator for the
rest of the arguments.
+ */
+ @varargs
+ def concat_ws(args: String*): String = {
+ val separator = args(0)
+ if (null == separator) {
+ return null
+ }
+
+ val sb = new JStringBuffer
+
+ var i = 1
+ val dataList = args.filter(null != _)
--- End diff --
Yes, good catch. :)
---
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.
---
