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
33namespace 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