01: /*
02: [The "BSD licence"]
03: Copyright (c) 2005-2006 Terence Parr
04: All rights reserved.
05:
06: Redistribution and use in source and binary forms, with or without
07: modification, are permitted provided that the following conditions
08: are met:
09: 1. Redistributions of source code must retain the above copyright
10: notice, this list of conditions and the following disclaimer.
11: 2. Redistributions in binary form must reproduce the above copyright
12: notice, this list of conditions and the following disclaimer in the
13: documentation and/or other materials provided with the distribution.
14: 3. The name of the author may not be used to endorse or promote products
15: derived from this software without specific prior written permission.
16:
17: THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18: IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19: OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20: IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21: INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22: NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23: DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24: THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25: (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26: THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27: */
28: package org.antlr.runtime;
29:
30: /** A source of characters for an ANTLR lexer */
31: public interface CharStream extends IntStream {
32: public static final int EOF = -1;
33:
34: /** For infinite streams, you don't need this; primarily I'm providing
35: * a useful interface for action code. Just make sure actions don't
36: * use this on streams that don't support it.
37: */
38: public String substring(int start, int stop);
39:
40: /** Get the ith character of lookahead. This is the same usually as
41: * LA(i). This will be used for labels in the generated
42: * lexer code. I'd prefer to return a char here type-wise, but it's
43: * probably better to be 32-bit clean and be consistent with LA.
44: */
45: public int LT(int i);
46:
47: /** ANTLR tracks the line information automatically */
48: int getLine();
49:
50: /** Because this stream can rewind, we need to be able to reset the line */
51: void setLine(int line);
52:
53: void setCharPositionInLine(int pos);
54:
55: /** The index of the character relative to the beginning of the line 0..n-1 */
56: int getCharPositionInLine();
57: }
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