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
36    /** <summary>A source of characters for an ANTLR lexer</summary> */
37    public interface ICharStream : IIntStream
38    {
39
40        /** <summary>
41         *  For infinite streams, you don't need this; primarily I'm providing
42         *  a useful interface for action code.  Just make sure actions don't
43         *  use this on streams that don't support it.
44         *  </summary>
45         */
46        string Substring( int start, int length );
47
48        /** <summary>
49         *  Get the ith character of lookahead.  This is the same usually as
50         *  LA(i).  This will be used for labels in the generated
51         *  lexer code.  I'd prefer to return a char here type-wise, but it's
52         *  probably better to be 32-bit clean and be consistent with LA.
53         *  </summary>
54         */
55        int LT( int i );
56
57        /** <summary>ANTLR tracks the line information automatically</summary> */
58        /** <summary>Because this stream can rewind, we need to be able to reset the line</summary> */
59        int Line
60        {
61            get;
62            set;
63        }
64
65        /** <summary>The index of the character relative to the beginning of the line 0..n-1</summary> */
66        int CharPositionInLine
67        {
68            get;
69            set;
70        }
71    }
72}
73