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/*
* [The "BSD licence"]
* Copyright (c) 2005-2008 Terence Parr
* All rights reserved.
*
* Conversion to C#:
* Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
namespace Antlr.Runtime {
/** <summary>A stream of tokens accessing tokens from a TokenSource</summary> */
public interface ITokenStream : IIntStream {
/** <summary>Get Token at current input pointer + i ahead where i=1 is next Token.
* i&lt;0 indicates tokens in the past. So -1 is previous token and -2 is
* two tokens ago. LT(0) is undefined. For i&gt;=n, return Token.EOFToken.
* Return null for LT(0) and any index that results in an absolute address
* that is negative.</summary>
*/
IToken LT(int k);
/// <summary>
/// How far ahead has the stream been asked to look? The return
/// value is a valid index from 0..n-1.
/// </summary>
int Range {
get;
}
/** <summary>
* Get a token at an absolute index i; 0..n-1. This is really only
* needed for profiling and debugging and token stream rewriting.
* If you don't want to buffer up tokens, then this method makes no
* sense for you. Naturally you can't use the rewrite stream feature.
* I believe DebugTokenStream can easily be altered to not use
* this method, removing the dependency.
* </summary>
*/
IToken Get(int i);
/** <summary>
* Where is this stream pulling tokens from? This is not the name, but
* the object that provides Token objects.
* </summary>
*/
ITokenSource TokenSource {
get;
}
/** <summary>
* Return the text of all tokens from start to stop, inclusive.
* If the stream does not buffer all the tokens then it can just
* return "" or null; Users should not access $ruleLabel.text in
* an action of course in that case.
* </summary>
*/
string ToString(int start, int stop);
/** <summary>
* Because the user is not required to use a token with an index stored
* in it, we must provide a means for two token objects themselves to
* indicate the start/end location. Most often this will just delegate
* to the other toString(int,int). This is also parallel with
* the TreeNodeStream.toString(Object,Object).
* </summary>
*/
string ToString(IToken start, IToken stop);
}
}