yaml-cpp example

#include "yaml.h"
#include <iostream>
#include <fstream>
#include <string>
#include <vector>

// our data models
struct Vec3
{
   float x, y, z;
};

struct Power
{
   std::string name;
   int damage;
}; struct Monster {   std::string name;   Vec3 position;
   std::vector <Power> powers;
};

// operators for parsing
void operator >> (const YAML::Node& node, Vec3& v)
{
   node[0] >> v.x;
   node[1] >> v.y;
   node[2] >> v.z;
}

void operator >> (const YAML::Node& node, Power& power)
{
   node["name"] >> power.name;
   node["damage"] >> power.damage;
}

void operator >> (const YAML::Node& node, Monster& monster)
{
    node["name"] >> monster.name;
    node["position"] >> monster.position;
    const YAML::Node& powers = node["powers"];
    for(unsigned i = 0; i < powers.size(); i++)
    {
        Power power;
        powers[i] >> power;
        monster.powers.push_back(power);
    }
}

// operators for emitting
YAML::Emitter& operator << (YAML::Emitter& out, const Vec3& v)
{
    out << YAML::Flow;
    out << YAML::BeginSeq << v.x << v.y << v.z << YAML::EndSeq;
    return out;
}

YAML::Emitter& operator << (YAML::Emitter& out, const Power& power)
{
    out << YAML::BeginMap;
    out << YAML::Key << "name";
    out << YAML::Value << power.name;
    out << YAML::Key << "damage";
    out << YAML::Value << power.damage;
    out << YAML::EndMap;
    return out;
}

YAML::Emitter& operator << (YAML::Emitter& out, const Monster& monster)
{
    out << YAML::BeginMap;
    out << YAML::Key << "name";
    out << YAML::Value << monster.name;
    out << YAML::Key << "position";
    out << YAML::Value << monster.position;
    out << YAML::Key << "powers";
    out << YAML::Value;
    out << YAML::BeginSeq;
    for(size_t pidx = 0; pidx < monster.powers.size(); ++pidx)
    {
        out << monster.powers[pidx];
    }
    out << YAML::EndSeq;
    out << YAML::EndMap;
    return out;
}


int main()
{
   std::string monsters_yaml("- name: Ogre\n  position: [0, 5, 0]\n  powers:\n    - name: Club\n      damage: 10\n    - name: Fist\n      damage: 8\n- name: Dragon\n  position: [1, 0, 10]\n  powers:\n    - name: Fire Breath\n      damage: 25\n    - name: Claws\n      damage: 15\n- name: Wizard\n  position: [5, -3, 0]\n  powers:\n    - name: Acid Rain\n      damage: 50\n    - name: Staff\n      damage: 3\n");

    // list of monsters
    std::vector<Monster> monsters;

    // write out the monster.yaml
    std::ofstream monsters_yaml_file;
    monsters_yaml_file.open("monsters.yaml");
    monsters_yaml_file << monsters_yaml;
    monsters_yaml_file.close();

    // read in the the monster.yaml
    std::ifstream fin("monsters.yaml");
    YAML::Parser parser(fin);
    YAML::Node doc;
    parser.GetNextDocument(doc);
    for(size_t i = 0; i < doc.size(); i++)
    {
        Monster monster;
        doc[i] >> monster;
        monsters.push_back(monster);
        std::cout << monster.name << std::endl;
    }

    YAML::Emitter out;
    out << YAML::BeginSeq;
    for(size_t i = 0; i < monsters.size(); i++)
    {
        out << monsters[i];
    }
    out << YAML::EndSeq;

    std::cout << out.c_str() << std::endl;
    return 0;
}