xapian-applications/omega/jsonescape.h

   1 /** @file
   2  * @brief JSON escaping
   3  */
   4 /* Copyright (C) 2013,2018,2019,2021 Olly Betts
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to
   8  * deal in the Software without restriction, including without limitation the
   9  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
  10  * sell copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  22  * IN THE SOFTWARE.
  23  */
  24
  25 #ifndef OMEGA_INCLUDED_JSONESCAPE_H
  26 #define OMEGA_INCLUDED_JSONESCAPE_H
  27
  28 #include <string>
  29
  30 void json_escape(std::string &s);
  31
  32 /// Convert a C++ std::map to JSON.
  33 template<typename C, typename F1, typename F2>
  34 static inline std::string
  35 to_json(const C& container, F1 func1, F2 func2)
  36 {
  37     std::string result = "{\"";
  38     bool first = true;
  39     for (auto entry : container) {
  40         if (first) {
  41             first = false;
  42         } else {
  43             result += ",\"";
  44         }
  45         std::string key = func1(entry.first);
  46         json_escape(key);
  47         result += key;
  48         result += "\":";
  49         result += func2(entry.second);
  50     }
  51     if (first) {
  52         // Special case for an empty object.
  53         result = "{}";
  54     } else {
  55         result += "}";
  56     }
  57     return result;
  58 }
  59
  60 #endif // OMEGA_INCLUDED_JSONESCAPE_H