1 files changed, 102 insertions, 0 deletions
diff --git a/lib/Json.cpp b/lib/Json.cpp
new file mode 100644
index 0000000..9bda8c3
--- /dev/null
+++ b/lib/Json.cpp
@@ -0,0 +1,102 @@
+/*
+   Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012
+   Her Majesty the Queen in Right of Canada (Communications Research
+   Center Canada)
+
+   Copyright (C) 2023
+   Matthias P. Braendli, matthias.braendli@mpb.li
+
+    http://www.opendigitalradio.org
+ */
+/*
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#include <list>
+#include <string>
+#include <iostream>
+#include <sstream>
+#include <iomanip>
+#include <string>
+#include <algorithm>
+
+#include "Json.h"
+
+namespace json {
+    static std::string escape_json(const std::string &s) {
+        std::ostringstream o;
+        for (auto c = s.cbegin(); c != s.cend(); c++) {
+            switch (*c) {
+                case '"': o << "\\\""; break;
+                case '\\': o << "\\\\"; break;
+                case '\b': o << "\\b"; break;
+                case '\f': o << "\\f"; break;
+                case '\n': o << "\\n"; break;
+                case '\r': o << "\\r"; break;
+                case '\t': o << "\\t"; break;
+                default:
+                           if ('\x00' <= *c && *c <= '\x1f') {
+                               o << "\\u"
+                                   << std::hex << std::setw(4) << std::setfill('0') << static_cast<int>(*c);
+                           } else {
+                               o << *c;
+                           }
+            }
+        }
+        return o.str();
+    }
+
+    std::string map_to_json(const map_t& values) {
+        std::ostringstream ss;
+        ss << "{ ";
+        size_t ix = 0;
+        for (const auto& element : values) {
+            if (ix > 0) {
+                ss << ",";
+            }
+
+            ss << "\"" << escape_json(element.first) << "\": ";
+
+            const auto& value = element.second.data;
+            if (std::holds_alternative<std::string>(value)) {
+                ss << "\"" << escape_json(std::get<std::string>(value)) << "\"";
+            }
+            else if (std::holds_alternative<double>(value)) {
+                ss << std::defaultfloat << std::get<double>(value);
+            }
+            else if (std::holds_alternative<ssize_t>(value)) {
+                ss << std::get<ssize_t>(value);
+            }
+            else if (std::holds_alternative<size_t>(value)) {
+                ss << std::get<size_t>(value);
+            }
+            else if (std::holds_alternative<bool>(value)) {
+                ss << (std::get<bool>(value) ? "true" : "false");
+            }
+            else if (std::holds_alternative<std::nullopt_t>(value)) {
+                ss << "null";
+            }
+            else if (std::holds_alternative<json::map_t>(value)) {
+                ss << map_to_json(std::get<json::map_t>(value));
+            }
+            else {
+                throw std::logic_error("variant alternative not handled");
+            }
+
+            ix++;
+        }
+        ss << " }";
+
+        return ss.str();
+    }
+}