parse_stdin.cpp

#include "cpptoml.h"

#include <iostream>
#include <limits>

std::string escape_string(const std::string& str)
{
    std::string res;
    for (auto it = str.begin(); it != str.end(); ++it)
    {
        if (*it == '\\')
            res += "\\\\";
        else if (*it == '"')
            res += "\\\"";
        else if (*it == '\n')
            res += "\\n";
        else
            res += *it;
    }
    return res;
}

/**
 * A visitor for toml objects that writes to an output stream in the JSON
 * format that the toml-test suite expects.
 */
class toml_test_writer
{
  public:
    toml_test_writer(std::ostream& s) : stream_(s)
    {
        // nothing
    }

    void visit(const cpptoml::value<std::string>& v)
    {
        stream_ << "{\"type\":\"string\",\"value\":\"" << escape_string(v.get())
                << "\"}";
    }

    void visit(const cpptoml::value<int64_t>& v)
    {
        stream_ << "{\"type\":\"integer\",\"value\":\"" << v.get() << "\"}";
    }

    void visit(const cpptoml::value<double>& v)
    {
        stream_ << "{\"type\":\"float\",\"value\":\"" << v.get() << "\"}";
    }

    void visit(const cpptoml::value<cpptoml::datetime>& v)
    {
        stream_ << "{\"type\":\"datetime\",\"value\":\"" << v.get() << "\"}";
    }

    void visit(const cpptoml::value<bool>& v)
    {
        stream_ << "{\"type\":\"bool\",\"value\":\"" << v << "\"}";
    }

    void visit(const cpptoml::array& arr)
    {
        stream_ << "{\"type\":\"array\",\"value\":[";
        auto it = arr.get().begin();
        while (it != arr.get().end())
        {
            (*it)->accept(*this);
            if (++it != arr.get().end())
                stream_ << ", ";
        }
        stream_ << "]}";
    }

    void visit(const cpptoml::table_array& tarr)
    {
        stream_ << "[";
        auto arr = tarr.get();
        auto ait = arr.begin();
        while (ait != arr.end())
        {
            (*ait)->accept(*this);
            if (++ait != arr.end())
                stream_ << ", ";
        }
        stream_ << "]";
    }

    void visit(const cpptoml::table& t)
    {
        stream_ << "{";
        auto it = t.begin();
        while (it != t.end())
        {
            stream_ << '"' << escape_string(it->first) << "\":";
            it->second->accept(*this);
            if (++it != t.end())
                stream_ << ", ";
        }
        stream_ << "}";
    }

  private:
    std::ostream& stream_;
};

int main()
{
    std::cout.precision(std::numeric_limits<double>::max_digits10);
    cpptoml::parser p{std::cin};
    try
    {
        std::shared_ptr<cpptoml::table> g = p.parse();
        toml_test_writer writer{std::cout};
        g->accept(writer);
        std::cout << std::endl;
    }
    catch (const cpptoml::parse_exception& ex)
    {
        std::cerr << "Parsing failed: " << ex.what() << std::endl;
        return 1;
    }
    catch (...)
    {
        std::cerr << "Something horrible happened!" << std::endl;
        // return as if there was success so that toml-test will complain
        return 0;
    }
    return 0;
}