File re2.h
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// Copyright 2019 The MediaPipe Authors.
//
// Licensed 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.
#ifndef MEDIAPIPE_FRAMEWORK_DEPS_RE2_H_
#define MEDIAPIPE_FRAMEWORK_DEPS_RE2_H_
#include <regex> // NOLINT
namespace mediapipe {
// Implements a subset of RE2 using std::regex_match.
class RE2 {
public:
RE2(const std::string& pattern) : std_regex_(pattern) {}
static bool FullMatch(std::string text, const RE2& re) {
return std::regex_match(text, re.std_regex_);
}
static bool PartialMatch(std::string text, const RE2& re) {
return std::regex_search(text, re.std_regex_);
}
static int GlobalReplace(std::string* text, const RE2& re,
const std::string& rewrite) {
std::smatch sm;
std::regex_search(*text, sm, re.std_regex_);
*text = std::regex_replace(*text, re.std_regex_, rewrite);
return std::max(0, static_cast<int>(sm.size()) - 1);
}
private:
std::regex std_regex_;
};
// Implements LazyRE2 using std::call_once.
class LazyRE2 {
public:
RE2& operator*() const {
std::call_once(once_, [&]() { ptr_ = new RE2(pattern_); });
return *ptr_;
}
RE2* operator->() const { return &**this; }
const char* pattern_;
mutable RE2* ptr_;
mutable std::once_flag once_;
};
} // namespace mediapipe
#endif // MEDIAPIPE_FRAMEWORK_DEPS_RE2_H_