uschindler commented on a change in pull request #581: LUCENE-3041: QueryVisitor URL: https://github.com/apache/lucene-solr/pull/581#discussion_r260869036
########## File path: lucene/core/src/java/org/apache/lucene/search/QueryVisitor.java ########## @@ -0,0 +1,123 @@ +/* + * 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.search; + +import java.util.function.Predicate; +import java.util.function.Supplier; + +import org.apache.lucene.index.Term; +import org.apache.lucene.util.BytesRef; +import org.apache.lucene.util.automaton.CompiledAutomaton; + +/** + * Interface to allow recursion through a query tree + * + * @see Query#visit(QueryVisitor) + */ +public interface QueryVisitor { + + /** + * Called by leaf queries that match on a specific term + * @param query the leaf query visited + * @param term the term the query will match on + */ + void visitLeaf(Query query, Term term); + + /** + * Called by leaf queries that do not match against the terms index + * @param query the leaf query visited + */ + default void visitLeaf(Query query) {} + + /** + * Called by leaf queries that match against a set of terms defined by a predicate + * @param query the leaf query + * @param field the field the query matches against + * @param predicateSupplier a supplier for a predicate that will select matching terms + */ + default void visitLeaf(Query query, String field, Supplier<Predicate<BytesRef>> predicateSupplier) {} Review comment: If the visitor API works in general, adding more methods to improve usability (maybe using functional interfaces) would be a great win. I agree, can be done later. The most important parts are covered here, so I am fine. I will still look at the code this evening to check if I find some problems. Most of the patch here deals with extractTerms, the actual changes in API are minor... ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
