ICharStream.cs revision 324c4644fee44b9898524c09511bd33c3f12e2df 
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    /** <summary>A source of characters for an ANTLR lexer</summary> */
36    public interface ICharStream : IIntStream {
37
38        /** <summary>
39         *  For infinite streams, you don't need this; primarily I'm providing
40         *  a useful interface for action code.  Just make sure actions don't
41         *  use this on streams that don't support it.
42         *  </summary>
43         */
44        string Substring(int start, int length);
45
46        /** <summary>
47         *  Get the ith character of lookahead.  This is the same usually as
48         *  LA(i).  This will be used for labels in the generated
49         *  lexer code.  I'd prefer to return a char here type-wise, but it's
50         *  probably better to be 32-bit clean and be consistent with LA.
51         *  </summary>
52         */
53        int LT(int i);
54
55        /** <summary>ANTLR tracks the line information automatically</summary> */
56        /** <summary>Because this stream can rewind, we need to be able to reset the line</summary> */
57        int Line {
58            get;
59            set;
60        }
61
62        /** <summary>The index of the character relative to the beginning of the line 0..n-1</summary> */
63        int CharPositionInLine {
64            get;
65            set;
66        }
67    }
68}
69