1 /* 2 * [The "BSD license"] 3 * Copyright (c) 2011 Terence Parr 4 * All rights reserved. 5 * 6 * Conversion to C#: 7 * Copyright (c) 2011 Sam Harwell, Pixel Mine, Inc. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 namespace Antlr.Runtime.Misc 34 { 35 using System.Collections.Generic; 36 using InvalidOperationException = System.InvalidOperationException; 37 38 public class ListStack<T> : List<T> 39 { Peek()40 public T Peek() 41 { 42 return Peek(0); 43 } 44 Peek(int depth)45 public T Peek(int depth) 46 { 47 T item; 48 if (!TryPeek(depth, out item)) 49 throw new InvalidOperationException(); 50 51 return item; 52 } 53 TryPeek(out T item)54 public bool TryPeek(out T item) 55 { 56 return TryPeek(0, out item); 57 } 58 TryPeek(int depth, out T item)59 public bool TryPeek(int depth, out T item) 60 { 61 if (depth >= Count) 62 { 63 item = default(T); 64 return false; 65 } 66 67 item = this[Count - depth - 1]; 68 return true; 69 } 70 Pop()71 public T Pop() 72 { 73 T result; 74 if (!TryPop(out result)) 75 throw new InvalidOperationException(); 76 77 return result; 78 } 79 TryPop(out T item)80 public bool TryPop(out T item) 81 { 82 if (Count == 0) 83 { 84 item = default(T); 85 return false; 86 } 87 88 item = this[Count - 1]; 89 RemoveAt(Count - 1); 90 return true; 91 } 92 Push(T item)93 public void Push(T item) 94 { 95 Add(item); 96 } 97 } 98 } 99