arrow/util/regex.h

0001 // Licensed to the Apache Software Foundation (ASF) under one
0002 // or more contributor license agreements.  See the NOTICE file
0003 // distributed with this work for additional information
0004 // regarding copyright ownership.  The ASF licenses this file
0005 // to you under the Apache License, Version 2.0 (the
0006 // "License"); you may not use this file except in compliance
0007 // with the License.  You may obtain a copy of the License at
0008 //
0009 //   http://www.apache.org/licenses/LICENSE-2.0
0010 //
0011 // Unless required by applicable law or agreed to in writing,
0012 // software distributed under the License is distributed on an
0013 // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
0014 // KIND, either express or implied.  See the License for the
0015 // specific language governing permissions and limitations
0016 // under the License.
0017
0018 #pragma once
0019
0020 #include <cassert>
0021 #include <initializer_list>
0022 #include <regex>
0023 #include <string_view>
0024 #include <type_traits>
0025
0026 #include "arrow/util/visibility.h"
0027
0028 namespace arrow {
0029 namespace internal {
0030
0031 /// Match regex against target and produce string_views out of matches.
0032 inline bool RegexMatch(const std::regex& regex, std::string_view target,
0033                        std::initializer_list<std::string_view*> out_matches) {
0034   assert(regex.mark_count() == out_matches.size());
0035
0036   std::match_results<decltype(target.begin())> match;
0037   if (!std::regex_match(target.begin(), target.end(), match, regex)) {
0038     return false;
0039   }
0040
0041   // Match #0 is the whole matched sequence
0042   assert(regex.mark_count() + 1 == match.size());
0043   auto out_it = out_matches.begin();
0044   for (size_t i = 1; i < match.size(); ++i) {
0045     **out_it++ = target.substr(match.position(i), match.length(i));
0046   }
0047   return true;
0048 }
0049
0050 }  // namespace internal
0051 }  // namespace arrow