Запись данных в формате JSON

#include <iostream>
#include <unordered_map>
#include <boost/property_tree/json_parser.hpp>

int main()
{
    auto pt = boost::property_tree::ptree{};
    pt.put("Comment", "My comment");
    pt.put("Count", 10);
    pt.put("DiskParam.DB", 10.0);
    pt.put("DiskParam.DBAngle", 1.234);
    pt.put("Range", true);

    auto blades = std::unordered_map<std::string, int>{{"A", 1}, {"B", 2}, {"C", 2}};

    auto bladesTree = boost::property_tree::ptree{};
    for (const auto &kv : blades) {
        auto blade = boost::property_tree::ptree{};
        blade.add("Caption", kv.first);
        blade.add("Value", kv.second);
        bladesTree.push_back(std::make_pair("", blade));
    }

    pt.add_child("Blades", bladesTree);

    auto slotsTree = boost::property_tree::ptree{};
    for (auto i = 0; i < 3; i++) {
        auto slot = boost::property_tree::ptree{std::to_string(i)};
        slotsTree.push_back(std::make_pair("", slot));
    }

    pt.add_child("Slots", slotsTree);

    auto buf = std::ostringstream{};
    boost::property_tree::write_json(buf, pt);
    std::cout << buf.str();
}

import Data.Char
import Data.List (intercalate)
        
data JValue = JString String
            | JNumber Double
            | JBool Bool
            | JNull
            | JObject [(String, JValue)]
            | JArray [JValue]
              deriving Show

renderJValue :: JValue -> String
renderJValue (JString s)   = show s
renderJValue (JNumber n)   = show n
renderJValue (JBool True)  = "true"
renderJValue (JBool False) = "false"
renderJValue JNull         = "null"
renderJValue (JObject o) = "{" ++ pairs o ++ "}"
    where pairs [] = ""
          pairs ps = intercalate ", " (map renderPair ps)
          renderPair (k, v) = show k ++ ": " ++ renderJValue v
renderJValue (JArray a) = "[" ++ values a ++ "]"
    where values [] = ""
          values vs = intercalate ", " (map renderJValue vs)
    
main = putStrLn $ renderJValue (JObject [
        ("Comment", JString "My comment"), 
        ("Count", JNumber 10),
        ("DiskParam", JObject [
            ("DB", JNumber 10), 
            ("DBAngle", JNumber 1.234)
        ]),
        ("Range", JBool True),
        ("Blades", JArray $ map (\ch -> 
            JObject [
                ("Caption", JString (ch:[])),
                ("Value", JNumber (fromIntegral (ord ch)))
            ])  ['A'..'C']),
        ("Slots", JArray [JNumber 0, JNumber 1, JNumber 2])
    ])

  OBJECT("")
  {
    VALUE("Comment", Header.Comment);
    VALUE("Count",   Header.Count);
    OBJECT("DiskParam")
    {
      VALUE("DB",      Header.DB);
      VALUE("DBAngle", Header.DBAngle);
    }
    VALUE("Range",   Header.Range);

    //Чтение массива с неизвестным числом элементов
    ARRAY_WHILE("Blades", BladeCount)
    {
      TBlade Blade;
      OBJECT("")
      {
        VALUE("Caption", Blade.Caption);
        VALUE("Value",   Blade.BaseChar);
      }
      if(!ERROR)
      {
        NewBlades=realloc(Blades, BladeCount+1);
        if(NewBlades)
        {
          Blades=NewBlades;
          Blades[BladeCount]=Blade;
        }
      }
    }

    //Чтение массива с известным или ограниченным числом элементов
    ARRAY_FOR("Slots", SlotsCount, MAX_ELEMENTS)
      VALUE("", Slots[SlotsCount]);

    //Обработка ситуаций, когда значение может быть неподходящего типа
    double Temp;
    VALUE("NCount", Temp)
      Header.NCount=(int)(Temp+0.5);
  }