[ https://issues.apache.org/jira/browse/FLINK-3708?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15251547#comment-15251547 ]
ASF GitHub Bot commented on FLINK-3708: --------------------------------------- Github user tillrohrmann commented on a diff in the pull request: https://github.com/apache/flink/pull/1905#discussion_r60542216 --- Diff: flink-libraries/flink-cep-scala/src/main/scala/org/apache/flink/cep/scala/pattern/package.scala --- @@ -0,0 +1,42 @@ +/* + * 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.cep.scala + +import org.apache.flink.cep.pattern.{FollowedByPattern => JFollowedByPattern, Pattern => JPattern} + +import _root_.scala.reflect.ClassTag + +package object pattern { + /** + * Utility method to wrap { @link org.apache.flink.cep.pattern.Pattern} and its subclasses + * for usage with the Scala API. + * + * @param javaPattern The underlying pattern from the Java API + * @tparam T Base type of the elements appearing in the pattern + * @tparam F Subtype of T to which the current pattern operator is constrained + * @return A pattern from the Scala API which wraps the pattern from the Java API + */ + private[flink] def wrapPattern[ + T: ClassTag, F <: T : ClassTag](javaPattern: JPattern[T, F]) + : Pattern[T, F] = javaPattern match { + case f: JFollowedByPattern[T, F] => FollowedByPattern[T, F](f) + case p: JPattern[T, F] => Pattern[T, F](p) + case _ => null --- End diff -- Oh yes, you're totally right Stefan. But then we could maybe return an `Option[Pattern]` from the `wrapPattern` method. > Scala API for CEP > ----------------- > > Key: FLINK-3708 > URL: https://issues.apache.org/jira/browse/FLINK-3708 > Project: Flink > Issue Type: Improvement > Components: CEP > Affects Versions: 1.1.0 > Reporter: Till Rohrmann > Assignee: Stefan Richter > > Currently, The CEP library does not support Scala case classes, because the > {{TypeExtractor}} cannot handle them. In order to support them, it would be > necessary to offer a Scala API for the CEP library. -- This message was sent by Atlassian JIRA (v6.3.4#6332)