1/* 2 * [The "BSD licence"] 3 * Copyright (c) 2005-2008 Terence Parr 4 * All rights reserved. 5 * 6 * Conversion to C#: 7 * Copyright (c) 2008-2009 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 */ 32namespace Antlr.Runtime { 33 34 /** <summary>A stream of tokens accessing tokens from a TokenSource</summary> */ 35 public interface ITokenStream : IIntStream { 36 /** <summary>Get Token at current input pointer + i ahead where i=1 is next Token. 37 * i<0 indicates tokens in the past. So -1 is previous token and -2 is 38 * two tokens ago. LT(0) is undefined. For i>=n, return Token.EOFToken. 39 * Return null for LT(0) and any index that results in an absolute address 40 * that is negative.</summary> 41 */ 42 IToken LT(int k); 43 44 /// <summary> 45 /// How far ahead has the stream been asked to look? The return 46 /// value is a valid index from 0..n-1. 47 /// </summary> 48 int Range { 49 get; 50 } 51 52 /** <summary> 53 * Get a token at an absolute index i; 0..n-1. This is really only 54 * needed for profiling and debugging and token stream rewriting. 55 * If you don't want to buffer up tokens, then this method makes no 56 * sense for you. Naturally you can't use the rewrite stream feature. 57 * I believe DebugTokenStream can easily be altered to not use 58 * this method, removing the dependency. 59 * </summary> 60 */ 61 IToken Get(int i); 62 63 /** <summary> 64 * Where is this stream pulling tokens from? This is not the name, but 65 * the object that provides Token objects. 66 * </summary> 67 */ 68 ITokenSource TokenSource { 69 get; 70 } 71 72 /** <summary> 73 * Return the text of all tokens from start to stop, inclusive. 74 * If the stream does not buffer all the tokens then it can just 75 * return "" or null; Users should not access $ruleLabel.text in 76 * an action of course in that case. 77 * </summary> 78 */ 79 string ToString(int start, int stop); 80 81 /** <summary> 82 * Because the user is not required to use a token with an index stored 83 * in it, we must provide a means for two token objects themselves to 84 * indicate the start/end location. Most often this will just delegate 85 * to the other toString(int,int). This is also parallel with 86 * the TreeNodeStream.toString(Object,Object). 87 * </summary> 88 */ 89 string ToString(IToken start, IToken stop); 90 } 91} 92