cpp/third_party/antlr4-cpp-runtime-4/runtime/src/support/CPPUtils.h

/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
 * Use of this file is governed by the BSD 3-clause license that
 * can be found in the LICENSE.txt file in the project root.
 */

#pragma once

#include "antlr4-common.h"

namespace antlrcpp {

  std::string join(std::vector<std::string> strings, const std::string &separator);
  std::map<std::string, size_t> toMap(const std::vector<std::string> &keys);
  std::string escapeWhitespace(std::string str, bool escapeSpaces);
  std::string toHexString(const int t);
  std::string arrayToString(const std::vector<std::string> &data);
  std::string replaceString(const std::string &s, const std::string &from, const std::string &to);
  std::vector<std::string> split(const std::string &s, const std::string &sep, int count);
  std::string indent(const std::string &s, const std::string &indentation, bool includingFirst = true);

  // Using RAII + a lambda to implement a "finally" replacement.
  template <typename OnEnd>
  struct FinalAction {
    FinalAction(OnEnd f) : _cleanUp { std::move(f) } {}
    FinalAction(FinalAction &&other) :
	_cleanUp(std::move(other._cleanUp)), _enabled(other._enabled) {
      other._enabled = false; // Don't trigger the lambda after ownership has moved.
    }
    ~FinalAction() { if (_enabled) _cleanUp(); }

    void disable() { _enabled = false; }
  private:
    OnEnd _cleanUp;
    bool _enabled {true};
  };

  template <typename OnEnd>
  FinalAction<OnEnd> finally(OnEnd f) {
    return FinalAction<OnEnd>(std::move(f));
  }

  // Convenience functions to avoid lengthy dynamic_cast() != nullptr checks in many places.
  template <typename T1, typename T2>
  inline bool is(T2 *obj) { // For pointer types.
    return dynamic_cast<typename std::add_const<T1>::type>(obj) != nullptr;
  }

  template <typename T1, typename T2>
  inline bool is(Ref<T2> const& obj) { // For shared pointers.
    return dynamic_cast<T1 *>(obj.get()) != nullptr;
  }

  template <typename T>
  std::string toString(const T &o) {
    std::stringstream ss;
    // typeid gives the mangled class name, but that's all what's possible
    // in a portable way.
    ss << typeid(o).name() << "@" << std::hex << reinterpret_cast<uintptr_t>(&o);
    return ss.str();
  }

  // Get the error text from an exception pointer or the current exception.
  std::string what(std::exception_ptr eptr = std::current_exception());

  class SingleWriteMultipleReadLock {
  public:
    void readLock();
    void readUnlock();
    void writeLock();
    void writeUnlock();

  private:
    std::condition_variable _readerGate;
    std::condition_variable _writerGate;

    std::mutex _mutex;
    size_t _activeReaders = 0;
    size_t _waitingWriters = 0;
    size_t _activeWriters = 0;
  };

} // namespace antlrcpp