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 */ 32 namespace Antlr.Runtime 33 { 34 35 /** <summary>A stream of tokens accessing tokens from a TokenSource</summary> */ 36 public interface ITokenStream : IIntStream 37 { 38 /** <summary>Get Token at current input pointer + i ahead where i=1 is next Token. 39 * i<0 indicates tokens in the past. So -1 is previous token and -2 is 40 * two tokens ago. LT(0) is undefined. For i>=n, return Token.EOFToken. 41 * Return null for LT(0) and any index that results in an absolute address 42 * that is negative.</summary> 43 */ 44 IToken LT( int k ); 45 46 /// <summary> 47 /// How far ahead has the stream been asked to look? The return 48 /// value is a valid index from 0..n-1. 49 /// </summary> 50 int Range 51 { 52 get; 53 } 54 55 /** <summary> 56 * Get a token at an absolute index i; 0..n-1. This is really only 57 * needed for profiling and debugging and token stream rewriting. 58 * If you don't want to buffer up tokens, then this method makes no 59 * sense for you. Naturally you can't use the rewrite stream feature. 60 * I believe DebugTokenStream can easily be altered to not use 61 * this method, removing the dependency. 62 * </summary> 63 */ 64 IToken Get( int i ); 65 66 /** <summary> 67 * Where is this stream pulling tokens from? This is not the name, but 68 * the object that provides Token objects. 69 * </summary> 70 */ 71 ITokenSource TokenSource 72 { 73 get; 74 } 75 76 /** <summary> 77 * Return the text of all tokens from start to stop, inclusive. 78 * If the stream does not buffer all the tokens then it can just 79 * return "" or null; Users should not access $ruleLabel.text in 80 * an action of course in that case. 81 * </summary> 82 */ 83 string ToString( int start, int stop ); 84 85 /** <summary> 86 * Because the user is not required to use a token with an index stored 87 * in it, we must provide a means for two token objects themselves to 88 * indicate the start/end location. Most often this will just delegate 89 * to the other toString(int,int). This is also parallel with 90 * the TreeNodeStream.toString(Object,Object). 91 * </summary> 92 */ 93 string ToString( IToken start, IToken stop ); 94 } 95 } 96
