1 /*
2  [The "BSD license"]
3  Copyright (c) 2012 Terence Parr
4  Copyright (c) 2012 Sam Harwell
5  All rights reserved.
6 
7  Redistribution and use in source and binary forms, with or without
8  modification, are permitted provided that the following conditions
9  are met:
10  1. Redistributions of source code must retain the above copyright
11      notice, this list of conditions and the following disclaimer.
12  2. Redistributions in binary form must reproduce the above copyright
13      notice, this list of conditions and the following disclaimer in the
14      documentation and/or other materials provided with the distribution.
15  3. The name of the author may not be used to endorse or promote products
16      derived from this software without specific prior written permission.
17 
18  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 namespace Antlr.Runtime.Tree
31 {
32     /**
33      *
34      * @author Sam Harwell
35      */
36     public interface IPositionTrackingStream
37     {
38         /**
39          * Returns an element containing concrete information about the current
40          * position in the stream.
41          *
42          * @param allowApproximateLocation if {@code false}, this method returns
43          * {@code null} if an element containing exact information about the current
44          * position is not available
45          */
GetKnownPositionElement(bool allowApproximateLocation)46         object GetKnownPositionElement(bool allowApproximateLocation);
47 
48         /**
49          * Determines if the specified {@code element} contains concrete position
50          * information.
51          *
52          * @param element the element to check
53          * @return {@code true} if {@code element} contains concrete position
54          * information, otherwise {@code false}
55          */
HasPositionInformation(object element)56         bool HasPositionInformation(object element);
57 
58     }
59 }
60