json_tool.h

// Copyright 2007-2010 Baptiste Lepilleur
// Distributed under MIT license, or public domain if desired and
// recognized in your jurisdiction.
// See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE

#ifndef LIB_JSONCPP_JSON_TOOL_H_INCLUDED
#define LIB_JSONCPP_JSON_TOOL_H_INCLUDED

/* This header provides common string manipulation support, such as UTF-8,
 * portable conversion from/to string...
 *
 * It is an internal header that must not be exposed.
 */

namespace Json {

/// Converts a unicode code-point to UTF-8.
static inline std::string codePointToUTF8(unsigned int cp) {
  std::string result;

  // based on description from http://en.wikipedia.org/wiki/UTF-8

  if (cp <= 0x7f) {
    result.resize(1);
    result[0] = static_cast<char>(cp);
  } else if (cp <= 0x7FF) {
    result.resize(2);
    result[1] = static_cast<char>(0x80 | (0x3f & cp));
    result[0] = static_cast<char>(0xC0 | (0x1f & (cp >> 6)));
  } else if (cp <= 0xFFFF) {
    result.resize(3);
    result[2] = static_cast<char>(0x80 | (0x3f & cp));
    result[1] = static_cast<char>(0x80 | (0x3f & (cp >> 6)));
    result[0] = static_cast<char>(0xE0 | (0xf & (cp >> 12)));
  } else if (cp <= 0x10FFFF) {
    result.resize(4);
    result[3] = static_cast<char>(0x80 | (0x3f & cp));
    result[2] = static_cast<char>(0x80 | (0x3f & (cp >> 6)));
    result[1] = static_cast<char>(0x80 | (0x3f & (cp >> 12)));
    result[0] = static_cast<char>(0xF0 | (0x7 & (cp >> 18)));
  }

  return result;
}

/// Returns true if ch is a control character (in range [1,31]).
static inline bool isControlCharacter(char ch) { return ch > 0 && ch <= 0x1F; }

enum {
  /// Constant that specify the size of the buffer that must be passed to
  /// uintToString.
  uintToStringBufferSize = 3 * sizeof(LargestUInt) + 1
};

// Defines a char buffer for use with uintToString().
typedef char UIntToStringBuffer[uintToStringBufferSize];

/** Converts an unsigned integer to string.
 * @param value Unsigned interger to convert to string
 * @param current Input/Output string buffer.
 *        Must have at least uintToStringBufferSize chars free.
 */
static inline void uintToString(LargestUInt value, char*& current) {
  *--current = 0;
  do {
    *--current = static_cast<signed char>(value % 10U + static_cast<unsigned>('0'));
    value /= 10;
  } while (value != 0);
}

/** Change ',' to '.' everywhere in buffer.
 *
 * We had a sophisticated way, but it did not work in WinCE.
 * @see https://github.com/open-source-parsers/jsoncpp/pull/9
 */
static inline void fixNumericLocale(char* begin, char* end) {
  while (begin < end) {
    if (*begin == ',') {
      *begin = '.';
    }
    ++begin;
  }
}

} // namespace Json {

#endif // LIB_JSONCPP_JSON_TOOL_H_INCLUDED