#include <fstream>

#include <iostream>

#include <vector>

#include "yaml-cpp/eventhandler.h"

#include "yaml-cpp/yaml.h" // IWYU pragma: keep

class NullEventHandler : public YAML::EventHandler {

public:

void OnDocumentStart(const YAML::Mark&) override {}

void OnDocumentEnd() override {}

void OnNull(const YAML::Mark&, YAML::anchor_t) override {}

void OnAlias(const YAML::Mark&, YAML::anchor_t) override {}

void OnScalar(const YAML::Mark&, const std::string&, YAML::anchor_t,

const std::string&) override {}

void OnSequenceStart(const YAML::Mark&, const std::string&, YAML::anchor_t,

YAML::EmitterStyle::value) override {}

void OnSequenceEnd() override {}

void OnMapStart(const YAML::Mark&, const std::string&, YAML::anchor_t,

YAML::EmitterStyle::value) override {}

void OnMapEnd() override {}

};

void parse(std::istream& input) {

try {

YAML::Node doc = YAML::Load(input);

std::cout << doc << "\n";

} catch (const YAML::Exception& e) {

std::cerr << e.what() << "\n";

}

}

int main(int argc, char** argv) {

if (argc > 1) {

std::ifstream fin;

fin.open(argv[1]);

parse(fin);

} else {

parse(std::cin);

}

return 0;

}