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 33 namespace Antlr.Runtime 34 { 35 public static class TokenChannels 36 { 37 /** <summary> 38 * All tokens go to the parser (unless skip() is called in that rule) 39 * on a particular "channel". The parser tunes to a particular channel 40 * so that whitespace etc... can go to the parser on a "hidden" channel. 41 * </summary> 42 */ 43 public const int Default = 0; 44 45 /** <summary> 46 * Anything on different channel than DEFAULT_CHANNEL is not parsed 47 * by parser. 48 * </summary> 49 */ 50 public const int Hidden = 99; 51 } 52 53 public static class TokenTypes 54 { 55 public const int EndOfFile = (int)CharStreamConstants.EndOfFile; 56 public const int Invalid = 0; 57 public const int EndOfRule = 1; 58 /** <summary>imaginary tree navigation type; traverse "get child" link</summary> */ 59 public const int Down = 2; 60 /** <summary>imaginary tree navigation type; finish with a child list</summary> */ 61 public const int Up = 3; 62 public const int Min = Up + 1; 63 } 64 65 public static class Tokens 66 { 67 public static readonly IToken EndOfFile = Tokens<CommonToken>.EndOfFile; 68 69 public static readonly IToken Invalid = new CommonToken( TokenTypes.Invalid ); 70 71 /** <summary> 72 * In an action, a lexer rule can set token to this SKIP_TOKEN and ANTLR 73 * will avoid creating a token for this symbol and try to fetch another. 74 * </summary> 75 */ 76 public static readonly IToken Skip = new CommonToken( TokenTypes.Invalid ); 77 } 78 79 public static class Tokens<T> 80 where T : IToken, new() 81 { 82 public static readonly T EndOfFile = new T() 83 { 84 Type = TokenTypes.EndOfFile 85 }; 86 87 public static readonly T Invalid = new T() 88 { 89 Type = TokenTypes.Invalid 90 }; 91 92 public static readonly T Skip = new T() 93 { 94 Type = TokenTypes.Invalid 95 }; 96 } 97 } 98