/AvalonEdit/ICSharpCode.AvalonEdit/Utils/ImmutableStack.cs
http://github.com/icsharpcode/ILSpy · C# · 132 lines · 71 code · 13 blank · 48 comment · 4 complexity · 52876920a9ce8283727e3d01f7014827 MD5 · raw file
- // Copyright (c) 2014 AlphaSierraPapa for the SharpDevelop Team
- //
- // 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.Generic;
- using System.Diagnostics;
- using System.Text;
- namespace ICSharpCode.AvalonEdit.Utils
- {
- /// <summary>
- /// An immutable stack.
- ///
- /// Using 'foreach' on the stack will return the items from top to bottom (in the order they would be popped).
- /// </summary>
- [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1710:IdentifiersShouldHaveCorrectSuffix")]
- [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1711:IdentifiersShouldNotHaveIncorrectSuffix")]
- [Serializable]
- public sealed class ImmutableStack<T> : IEnumerable<T>
- {
- /// <summary>
- /// Gets the empty stack instance.
- /// </summary>
- [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2104:DoNotDeclareReadOnlyMutableReferenceTypes", Justification = "ImmutableStack is immutable")]
- [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1000:DoNotDeclareStaticMembersOnGenericTypes")]
- public static readonly ImmutableStack<T> Empty = new ImmutableStack<T>();
-
- readonly T value;
- readonly ImmutableStack<T> next;
-
- private ImmutableStack()
- {
- }
-
- private ImmutableStack(T value, ImmutableStack<T> next)
- {
- this.value = value;
- this.next = next;
- }
-
- /// <summary>
- /// Pushes an item on the stack. This does not modify the stack itself, but returns a new
- /// one with the value pushed.
- /// </summary>
- public ImmutableStack<T> Push(T item)
- {
- return new ImmutableStack<T>(item, this);
- }
-
- /// <summary>
- /// Gets the item on the top of the stack.
- /// </summary>
- /// <exception cref="InvalidOperationException">The stack is empty.</exception>
- public T Peek()
- {
- if (IsEmpty)
- throw new InvalidOperationException("Operation not valid on empty stack.");
- return value;
- }
-
- /// <summary>
- /// Gets the item on the top of the stack.
- /// Returns <c>default(T)</c> if the stack is empty.
- /// </summary>
- public T PeekOrDefault()
- {
- return value;
- }
-
- /// <summary>
- /// Gets the stack with the top item removed.
- /// </summary>
- /// <exception cref="InvalidOperationException">The stack is empty.</exception>
- public ImmutableStack<T> Pop()
- {
- if (IsEmpty)
- throw new InvalidOperationException("Operation not valid on empty stack.");
- return next;
- }
-
- /// <summary>
- /// Gets if this stack is empty.
- /// </summary>
- public bool IsEmpty {
- get { return next == null; }
- }
-
- /// <summary>
- /// Gets an enumerator that iterates through the stack top-to-bottom.
- /// </summary>
- public IEnumerator<T> GetEnumerator()
- {
- ImmutableStack<T> t = this;
- while (!t.IsEmpty) {
- yield return t.value;
- t = t.next;
- }
- }
-
- System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
- {
- return this.GetEnumerator();
- }
-
- /// <inheritdoc/>
- public override string ToString()
- {
- StringBuilder b = new StringBuilder("[Stack");
- foreach (T val in this) {
- b.Append(' ');
- b.Append(val);
- }
- b.Append(']');
- return b.ToString();
- }
- }
- }