Function json_string

tests/test_utils.cpp:207–250

}

std::string json_string(const std::string& json, const std::string& key) {
    std::string pattern = "\"" + key + "\":";
    size_t pos = json.find(pattern);
    if (pos == std::string::npos) return {};
    size_t start = pos + pattern.size();

    while (start < json.size() && (json[start] == ' ' || json[start] == '\t')) ++start;
    if (start >= json.size() || json[start] != '"') return {};
    ++start;

    std::string out;
    out.reserve(128);
    bool escaped = false;
    for (size_t i = start; i < json.size(); ++i) {
        char c = json[i];
        if (escaped) {
            switch (c) {
                case '"': out.push_back('"'); break;
                case '\\': out.push_back('\\'); break;
                case '/': out.push_back('/'); break;
                case 'b': out.push_back('\b'); break;
                case 'f': out.push_back('\f'); break;
                case 'n': out.push_back('\n'); break;
                case 'r': out.push_back('\r'); break;
                case 't': out.push_back('\t'); break;
                default: out.push_back(c); break;
            }
            escaped = false;
            continue;
        }

        if (c == '\\') {
            escaped = true;
            continue;
        }

        if (c == '"') {
            return out;
        }

        out.push_back(c);
    }
    return {};
}

std::string escape_json(const std::string& s) {
    std::ostringstream o;