| /* |
| * [The "BSD license"] |
| * Copyright (c) 2011 Terence Parr |
| * All rights reserved. |
| * |
| * Conversion to C#: |
| * Copyright (c) 2011 Sam Harwell, Pixel Mine, Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| namespace Antlr.Runtime.Misc |
| { |
| using System.Collections.Generic; |
| using InvalidOperationException = System.InvalidOperationException; |
| |
| public class ListStack<T> : List<T> |
| { |
| public T Peek() |
| { |
| return Peek(0); |
| } |
| |
| public T Peek(int depth) |
| { |
| T item; |
| if (!TryPeek(depth, out item)) |
| throw new InvalidOperationException(); |
| |
| return item; |
| } |
| |
| public bool TryPeek(out T item) |
| { |
| return TryPeek(0, out item); |
| } |
| |
| public bool TryPeek(int depth, out T item) |
| { |
| if (depth >= Count) |
| { |
| item = default(T); |
| return false; |
| } |
| |
| item = this[Count - depth - 1]; |
| return true; |
| } |
| |
| public T Pop() |
| { |
| T result; |
| if (!TryPop(out result)) |
| throw new InvalidOperationException(); |
| |
| return result; |
| } |
| |
| public bool TryPop(out T item) |
| { |
| if (Count == 0) |
| { |
| item = default(T); |
| return false; |
| } |
| |
| item = this[Count - 1]; |
| RemoveAt(Count - 1); |
| return true; |
| } |
| |
| public void Push(T item) |
| { |
| Add(item); |
| } |
| } |
| } |