mirror of https://github.com/icsharpcode/ILSpy.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
132 lines
4.1 KiB
132 lines
4.1 KiB
// Copyright (c) 2010-2013 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.NRefactory.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(); |
|
} |
|
} |
|
}
|
|
|