Import YamlDotNet.

Assets/YamlDotNet/Serialization/Utilities/ObjectAnchorCollection.cs

@@ -0,0 +1,75 @@
+// This file is part of YamlDotNet - A .NET library for YAML.
+// Copyright (c) Antoine Aubry and contributors
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+// of the Software, and to permit persons to whom the Software is furnished to do
+// so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using YamlDotNet.Core;
+
+namespace YamlDotNet.Serialization.Utilities
+{
+    internal sealed class ObjectAnchorCollection
+    {
+        private readonly IDictionary<string, object> objectsByAnchor = new Dictionary<string, object>();
+        private readonly IDictionary<object, string> anchorsByObject = new Dictionary<object, string>();
+
+        /// <summary>
+        /// Adds the specified anchor.
+        /// </summary>
+        /// <param name="anchor">The anchor.</param>
+        /// <param name="object">The @object.</param>
+        public void Add(string anchor, object @object)
+        {
+            objectsByAnchor.Add(anchor, @object);
+            if (@object != null)
+            {
+                anchorsByObject.Add(@object, anchor);
+            }
+        }
+
+        /// <summary>
+        /// Gets the anchor for the specified object.
+        /// </summary>
+        /// <param name="object">The object.</param>
+        /// <param name="anchor">The anchor.</param>
+        /// <returns></returns>
+        public bool TryGetAnchor(object @object, [MaybeNullWhen(false)] out string? anchor)
+        {
+            return anchorsByObject.TryGetValue(@object, out anchor);
+        }
+
+        /// <summary>
+        /// Gets the <see cref="object"/> with the specified anchor.
+        /// </summary>
+        /// <value></value>
+        public object this[string anchor]
+        {
+            get
+            {
+                if (objectsByAnchor.TryGetValue(anchor, out var value))
+                {
+                    return value;
+                }
+
+                throw new AnchorNotFoundException($"The anchor '{anchor}' does not exists");
+            }
+        }
+    }
+}