1 /*
2  * Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
3  * Use of this file is governed by the BSD 3-clause license that
4  * can be found in the LICENSE.txt file in the project root.
5  */
6 
7 package org.antlr.v4.runtime.atn;
8 
9 import org.antlr.v4.runtime.TokenStream;
10 
11 /**
12  * This class represents profiling event information for tracking the lookahead
13  * depth required in order to make a prediction.
14  *
15  * @since 4.3
16  */
17 public class LookaheadEventInfo extends DecisionEventInfo {
18 	/** The alternative chosen by adaptivePredict(), not necessarily
19 	 *  the outermost alt shown for a rule; left-recursive rules have
20 	 *  user-level alts that differ from the rewritten rule with a (...) block
21 	 *  and a (..)* loop.
22 	 */
23 	public int predictedAlt;
24 
25 	/**
26 	 * Constructs a new instance of the {@link LookaheadEventInfo} class with
27 	 * the specified detailed lookahead information.
28 	 *
29 	 * @param decision The decision number
30 	 * @param configs The final configuration set containing the necessary
31 	 * information to determine the result of a prediction, or {@code null} if
32 	 * the final configuration set is not available
33 	 * @param input The input token stream
34 	 * @param startIndex The start index for the current prediction
35 	 * @param stopIndex The index at which the prediction was finally made
36 	 * @param fullCtx {@code true} if the current lookahead is part of an LL
37 	 * prediction; otherwise, {@code false} if the current lookahead is part of
38 	 * an SLL prediction
39 	 */
LookaheadEventInfo(int decision, ATNConfigSet configs, int predictedAlt, TokenStream input, int startIndex, int stopIndex, boolean fullCtx)40 	public LookaheadEventInfo(int decision,
41 							  ATNConfigSet configs,
42 							  int predictedAlt,
43 							  TokenStream input, int startIndex, int stopIndex,
44 							  boolean fullCtx)
45 	{
46 		super(decision, configs, input, startIndex, stopIndex, fullCtx);
47 		this.predictedAlt = predictedAlt;
48 	}
49 }
50