uschindler commented on a change in pull request #173: URL: https://github.com/apache/lucene/pull/173#discussion_r646547379
########## File path: lucene/core/src/java/org/apache/lucene/util/Unwrapable.java ########## @@ -0,0 +1,41 @@ +/* + * 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.lucene.util; + +/** + * An object with this interface is a wrapper around another object + * (e.g., a filter with a delegate). The method {@link #unwrap()} can + * be called to get the wrapped object + * + * @lucene.internal + */ +public interface Unwrapable<T> { + + /** Unwraps this instance */ + T unwrap(); + + /** + * Unwraps all {@code Unwrapable}s around the given object. + */ + @SuppressWarnings("unchecked") + public static <T> T unwrapAll(T o) { Review comment: Thanks, this was some funny hack I applied after I got crazy to find a generic solution. What do you think: Maybe we should make a separate issue out of Unwrapable ? The problem here and why I did not add generics for the static method: Not all implementations you can pass in may implement unwrapable. java.nio.file.Path does not implement unwrappable and the idea of the static method is to pass in any Path and it will unwrap, if possible. This is a static method, so you can use it with any Path! If the path is not unwrappable, it would do nothing. -- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org
