using System.IO;

using System;

using System.Linq;

using YamlDotNet.Serialization;

using System.Collections.Generic;

using YamlDotNet.RepresentationModel;

​

namespace ConsoleApp1

{

    public class Program

    {

        public static void Main()

        {

            object yamlObject;

            using (var r = new StringReader(Program.Document))

                yamlObject = new Deserializer().Deserialize(r);

​

            var data = new YamlQuery(yamlObject)

                                .On("pods")

                                .Get("name")

                                .ToList<string>();

            Console.WriteLine("all names of pods");

            Console.WriteLine(string.Join(",", data));

​

​

            data = new YamlQuery(yamlObject)

                    .On("ressources")

                    .On("pods")

                    .Get("name")

                    .ToList<string>();

            Console.WriteLine("all names of pods in ressources");

            Console.WriteLine(string.Join(",", data));

​

        }

​

        public class YamlQuery

        {

            private object yamlDic;

            private string key;

            private object current;

​

            public YamlQuery(object yamlDic)

            {

                this.yamlDic = yamlDic;

            }

​

            public YamlQuery On(string key)

            {

                this.key = key;

                this.current = query<object>(this.current ?? this.yamlDic, this.key, null);

                return this;

            }

            public YamlQuery Get(string prop)

            {

                if (this.current == null)

                    throw new InvalidOperationException();

​

                this.current = query<object>(this.current, null, prop, this.key);

                return this;

            }

​

            public List<T> ToList<T>()

            {

                if (this.current == null)

                    throw new InvalidOperationException();

​

                return (this.current as List<object>).Cast<T>().ToList();

            }

​

​

            private void _query(YamlStream yaml)

            {

​

                // Examine the stream

                var mapping =

                    (YamlMappingNode)yaml.Documents[0].RootNode;

            }

​

            private IEnumerable<T> query<T>(object _dic, string key, string prop, string fromKey = null)

            {

                var result = new List<T>();

                if (_dic == null)

                    return result;

                if (typeof(IDictionary<object, object>).IsAssignableFrom(_dic.GetType()))

                {

                    var dic = (IDictionary<object, object>)_dic;

                    var d = dic.Cast<KeyValuePair<object, object>>();

​

                    foreach (var dd in d)

                    {

                        if (dd.Key as string == key)

                        {

                            if (prop == null)

                            { 

                                result.Add((T)dd.Value);

                            } else

                            { 

                                result.AddRange(query<T>(dd.Value, key, prop, dd.Key as string));

                            }

                        }

                        else if (fromKey == key && dd.Key as string == prop)

                        { 

                            result.Add((T)dd.Value);

                        }

                        else

                        { 

                            result.AddRange(query<T>(dd.Value, key, prop, dd.Key as string));

                        }

                    }

                }

                else if (typeof(IEnumerable<object>).IsAssignableFrom(_dic.GetType()))

                {

                    var t = (IEnumerable<object>)_dic;

                    foreach (var tt in t)

                    {

                        result.AddRange(query<T>(tt, key, prop, key));

                    }

​

                }

                return result;

            }

        }

​

​

​

        private const string Document = @"---

            receipt:    Oz-Ware Purchase Invoice

            date:        2007-08-06

            customer:

                given:   Dorothy

                family:  Gale

​

            pods:

                - name:   pod1

                  descrip:   Water Bucket (Filled)

                  price:     1.47

                  quantity:  4

​

                - name:   pod2

                  descrip:   High Heeled ""Ruby"" Slippers

                  price:     100.27

                  quantity:  1

                - name:   pod3

                  descrip:   High Heeled ""Ruby"" Slippers

                  ignore:    true

                  quantity:  1

​

            bill-to:  &id001

                street: |-

                        123 Tornado Alley

                        Suite 16

                city:   East Westville

                state:  KS

                pods:

                    - name: pod4

                      descrip:   High Heeled ""Ruby"" Slippers

                      price:     100.27

                      quantity:  

            ressources:

                      - pids:

                            - id: 1

                            - name: pid

                      - pods: 

                            - name: pod5

                              descrip:   High Heeled ""Ruby"" Slippers

                              price:     100.27

                              quantity:  

                            - name: pod6

                              descrip:   High Heeled ""Ruby"" Slippers

                              price:     100.27

                              quantity:  

            specialDelivery: >

                Follow the Yellow Brick

                Road to the Emerald City.

                Pay no attention to the

                man behind the curtain.

​

...";

    }

​

}