LiShuMing commented on a change in pull request #1401: [CALCITE-3280] Add regexp_replace function (Shuming Li) URL: https://github.com/apache/calcite/pull/1401#discussion_r317524365
########## File path: core/src/main/java/org/apache/calcite/runtime/RegexpFunctions.java ########## @@ -0,0 +1,106 @@ +/* + * 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.calcite.runtime; + +import java.util.regex.Matcher; +import java.util.regex.Pattern; + +import static org.apache.calcite.util.Static.RESOURCE; + +/** + * A collection of functions used in REGEXP processing. + */ +public class RegexpFunctions { + private RegexpFunctions() { + } + + /** SQL {@code REGEXP_REPLACE} function. */ + public static String regexpReplace(String s, String regex, String replacement) { + return regexpReplace(s, regex, replacement, 1, 0, null); + } + + /** SQL {@code REGEXP_REPLACE} function. */ + public static String regexpReplace(String s, String regex, String replacement, + Integer pos) { + return regexpReplace(s, regex, replacement, pos, 0, null); + } + + /** SQL {@code REGEXP_REPLACE} function. */ + public static String regexpReplace(String s, String regex, String replacement, + Integer pos, Integer occurrence) { + return regexpReplace(s, regex, replacement, pos, occurrence, null); + } + + /** SQL {@code REGEXP_REPLACE} function. */ + public static String regexpReplace(String s, String regex, String replacement, + Integer pos, Integer occurrence, String matchType) { + if (pos < 1 || pos > s.length()) { + throw RESOURCE.invalidInputForRegexpReplace(pos.toString()).ex(); + } + + // TODO: Matcher#appendReplacement(StringBuilder sb, String replacement) + // method is supported in JDK 1.9, and is not supported in JDK 1.8. + StringBuffer sb = new StringBuffer(); Review comment: Here I cannot find a good idea to use `StringBuilder` instead of `StringBuffer`. There is an api for this in JDK 1.9. ---------------------------------------------------------------- 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: [email protected] With regards, Apache Git Services
