source: Revenant/yamlprovider/include/yamlext.h@ 7ef8ec4

#ifndef __YAMLPROVIDERYAMLEXTENSIONS_H__
#define __YAMLPROVIDERYAMLEXTENSIONS_H__

#include <yaml.h>
#include <mars_util.h>
#include <stdarg.h>
#include <map>
#include <string>

namespace YAML
{
    template< typename T >
        static void operator >> (const Node & nd, T & target)
        {
        target = nd.as<T>();
        }
    
        template< typename T >
        void operator >> (const Node & nd, mars::Range< T > & rng)
        {
                if (nd.Type() == NodeType::Sequence)
                {
                        nd[0] >> rng.minimum;
                        nd[1] >> rng.maximum;
                        rng.update();
                } else
                {
                        nd >> rng.minimum;
                        nd >> rng.maximum;
                        rng.update();
                }
        }

        template< typename T >
        void operator >> (const Node & nd, mars::RangeX< T > & rng)
        {
                if (nd.Type() == NodeType::Sequence)
                {
                        nd[0] >> rng.minimum;
                        nd[1] >> rng.maximum;
                        rng.update();
                } else
                {
                        nd >> rng.minimum;
                        nd >> rng.maximum;
                        rng.update();
                }
        }

        template <typename L, typename E>
        static void operator >> (const Node & nd, L & l)
        {
                E e;

                if (nd.Type() == NodeType::Sequence)
                {
                        for (const_iterator it = nd.begin(); it != nd.end(); ++it)
                        {
                                *it >> e;
                                l.push_back(e);
                        }
                } else
                {
                        nd >> e;
                        l.push_back(e);
                }
        }

        template< typename E >
        class StringMapSchema
        {
        private:
                typedef std::map< std::string, E > MapType;
                
                MapType _map;

        public:
                StringMapSchema (const char * szFirst, /*const E & eFirst, */...)
                {
                        va_list vl;
                        const char * szIdent = szFirst;

                        va_start(vl, szFirst);
                        while(szIdent != NULL)
                        {
                                _map[szIdent] = static_cast< E > (va_arg(vl, int));
                                szIdent = va_arg(vl, const char *);
                        }
                        va_end(vl);
                }

                bool setValue (E & e, const std::string & s) const
                {
                        typename MapType::const_iterator i = _map.find(s);

                        if (i != _map.end())
                        {
                                e = i->second;
                                return true;
                        }

                        return false;                           
                }
        };

        template< typename E >
        class MappedValue
        {
        private:
                E & _e;
                const StringMapSchema< E > & _schema;

        public:
                MappedValue (E & e, const StringMapSchema< E > & schema)
                        : _e(e), _schema(schema) {}

                inline bool operator << (const std::string & s)
                        { return _schema.setValue(_e, s); }
        };

        template< typename E >
        class MappedRange
        {
        private:
                mars::Range< E > & _rng;
                const StringMapSchema< E > & _schema;

        public:
                MappedRange (mars::Range< E > & rng, const StringMapSchema< E > & schema)
                        : _rng(rng), _schema(schema) {}

                bool operator << (const std::string & s)
                {
                        E e;

                        if (_schema.setValue(e, s))
                        {
                                _rng.minimum = _rng.maximum = e;
                                _rng.update();
                                return true;
                        }

                        return false;                           
                }

                bool setRange (const std::string & sMin, const std::string & sMax)
                {
                        E eMin, eMax;

                        if (_schema.setValue(eMin, sMin) && _schema.setValue(eMax, sMax))
                        {
                                _rng.minimum = eMin;
                                _rng.maximum = eMax;
                                _rng.update();
                                return true;
                        }

                        return false;                           
                }
        };

        template< typename E >
        void operator >> (const Node & nd, MappedValue< E > mapped)
        {
                std::string s;

                nd >> s;
                if (!(mapped << s))
                        throw RepresentationException(nd.Mark(), "Unknown identifier for mapped value: " + s);
        }

        template< typename E >
        void operator >> (const Node & nd, MappedRange< E > mapped)
        {
                if (nd.Type() == NodeType::Sequence)
                {
                        std::string sMin, sMax;

                        nd[0] >> sMin;
                        nd[1] >> sMax;
                        if (!mapped.setRange(sMin, sMax))
                                throw RepresentationException(nd.Mark(), "Unknown identifier(s) for mapped range: " + sMin + "/" + sMax);
                } else
                {
                        std::string s;
                        nd >> s;
                        if (!(mapped << s))
                                throw RepresentationException(nd.Mark(), "Unknown identifier for mapped range: " + s);
                }
        }
}

#endif