Added NightAlert project for travel kit

ThirdParty/EngineIoClientDotNet/Src/Quobject.Collections.Immutable/ImmutableStack.cs

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+//
+// ImmutableStack.cs
+//
+// Author:
+//       Mike Krüger <mkrueger@xamarin.com>
+//
+// Copyright (c) 2013 Xamarin Inc. (http://xamarin.com)
+//
+// 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;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace Quobject.Collections.Immutable
+{
+    public class ImmutableStack<T> : IImmutableStack<T>
+    {
+        readonly T head;
+        readonly ImmutableStack<T> tail;
+
+        internal ImmutableStack()
+        {
+        }
+
+        ImmutableStack(T head, ImmutableStack<T> tail)
+        {
+            this.head = head;
+            this.tail = tail;
+        }
+        #region IImmutableStack implementation
+        internal static readonly ImmutableStack<T> Empty = new ImmutableStack<T>();
+
+        public bool IsEmpty
+        {
+            get { return tail == null; }
+        }
+
+        public ImmutableStack<T> Clear()
+        {
+            return Empty;
+        }
+
+        IImmutableStack<T> IImmutableStack<T>.Clear()
+        {
+            return Empty;
+        }
+
+        public T Peek()
+        {
+            if (IsEmpty)
+                throw new InvalidOperationException("Stack is empty.");
+            return head;
+        }
+
+        public ImmutableStack<T> Pop()
+        {
+            if (IsEmpty)
+                throw new InvalidOperationException("Stack is empty.");
+            return tail;
+        }
+
+        public ImmutableStack<T> Pop(out T value)
+        {
+            value = Peek();
+            return Pop();
+        }
+
+        IImmutableStack<T> IImmutableStack<T>.Pop()
+        {
+            return Pop();
+        }
+
+        public ImmutableStack<T> Push(T value)
+        {
+            return new ImmutableStack<T>(value, this);
+        }
+
+        IImmutableStack<T> IImmutableStack<T>.Push(T value)
+        {
+            return Push(value);
+        }
+        #endregion
+
+        #region IEnumerable<T> implementation
+
+        public IEnumerator<T> GetEnumerator()
+        {
+            return new Enumerator(this);
+        }
+
+        struct Enumerator : IEnumerator<T>
+        {
+            readonly ImmutableStack<T> start;
+            IImmutableStack<T> current;
+
+            public Enumerator(ImmutableStack<T> stack)
+            {
+                this.start = stack;
+                this.current = null;
+            }
+            #region IEnumerator implementation
+
+            bool IEnumerator.MoveNext()
+            {
+                if (current == null)
+                {
+                    current = this.start;
+                }
+                else if (!current.IsEmpty)
+                {
+                    current = current.Pop();
+                }
+
+                return !current.IsEmpty;
+            }
+
+            void IEnumerator.Reset()
+            {
+                current = null;
+            }
+
+            object IEnumerator.Current
+            {
+                get { return this.Current; }
+            }
+            #endregion
+
+            #region IDisposable implementation
+            void IDisposable.Dispose()
+            {
+            }
+            #endregion
+
+            #region IEnumerator implementation
+
+            public T Current
+            {
+                get
+                {
+                    return current != null ? current.Peek() : default(T);
+                }
+            }
+            #endregion
+        }
+        #endregion
+
+        #region IEnumerable implementation
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return this.GetEnumerator();
+        }
+        #endregion
+    }
+
+    public static class ImmutableStack
+    {
+        public static ImmutableStack<T> Create<T>()
+        {
+            return ImmutableStack<T>.Empty;
+        }
+
+        public static ImmutableStack<T> Create<T>(T item)
+        {
+            return Create<T>().Push(item);
+        }
+
+        public static ImmutableStack<T> Create<T>(IEnumerable<T> items)
+        {
+            var result = ImmutableStack<T>.Empty;
+            foreach (var item in items)
+                result = result.Push(item);
+            return result;
+        }
+
+        public static ImmutableStack<T> Create<T>(params T[] items)
+        {
+            return Create((IEnumerable<T>)items);
+        }
+
+        public static IImmutableStack<T> Pop<T>(this IImmutableStack<T> stack, out T value)
+        {
+            if (stack == null)
+                throw new ArgumentNullException("stack");
+            value = stack.Peek();
+            return stack.Pop();
+        }
+    }
+}