/*
 * Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
 * Use of this file is governed by the BSD 3-clause license that
 * can be found in the LICENSE.txt file in the project root.
 */

package org.antlr.v4.runtime.atn;

import org.antlr.v4.runtime.ANTLRErrorListener;
import org.antlr.v4.runtime.TokenStream;

import java.util.BitSet;

This class represents profiling event information for an ambiguity.
Ambiguities are decisions where a particular input resulted in an SLL
conflict, followed by LL prediction also reaching a conflict state
(indicating a true ambiguity in the grammar).
 This event may be reported during SLL prediction in cases where the conflicting SLL configuration set provides sufficient information to determine that the SLL conflict is truly an ambiguity. For example, if none of the ATN configurations in the conflicting SLL configuration set have traversed a global follow transition (i.e. ATNConfig.reachesIntoOuterContext is 0 for all configurations), then the result of SLL prediction for that input is known to be equivalent to the result of LL prediction for that input.
 In some cases, the minimum represented alternative in the conflicting LL configuration set is not equal to the minimum represented alternative in the conflicting SLL configuration set. Grammars and inputs which result in this scenario are unable to use PredictionMode.SLL, which in turn means they cannot use the two-stage parsing strategy to improve parsing performance for that input.
See Also:
ParserATNSimulator.reportAmbiguity
ANTLRErrorListener.reportAmbiguity
Since:
4.3/**
 * This class represents profiling event information for an ambiguity.
 * Ambiguities are decisions where a particular input resulted in an SLL
 * conflict, followed by LL prediction also reaching a conflict state
 * (indicating a true ambiguity in the grammar).
 *
 * <p>
 * This event may be reported during SLL prediction in cases where the
 * conflicting SLL configuration set provides sufficient information to
 * determine that the SLL conflict is truly an ambiguity. For example, if none
 * of the ATN configurations in the conflicting SLL configuration set have
 * traversed a global follow transition (i.e.
 * {@link ATNConfig#reachesIntoOuterContext} is 0 for all configurations), then
 * the result of SLL prediction for that input is known to be equivalent to the
 * result of LL prediction for that input.</p>
 *
 * <p>
 * In some cases, the minimum represented alternative in the conflicting LL
 * configuration set is not equal to the minimum represented alternative in the
 * conflicting SLL configuration set. Grammars and inputs which result in this
 * scenario are unable to use {@link PredictionMode#SLL}, which in turn means
 * they cannot use the two-stage parsing strategy to improve parsing performance
 * for that input.</p>
 *
 * @see ParserATNSimulator#reportAmbiguity
 * @see ANTLRErrorListener#reportAmbiguity
 *
 * @since 4.3
 */
public class AmbiguityInfo extends DecisionEventInfo {
	
The set of alternative numbers for this decision event that lead to a valid parse. /** The set of alternative numbers for this decision event that lead to a valid parse. */
	public BitSet ambigAlts;

	
Constructs a new instance of the AmbiguityInfo class with the specified detailed ambiguity information. 
Params:
decision – The decision number
configs – The final configuration set identifying the ambiguous
alternatives for the current input
ambigAlts – The set of alternatives in the decision that lead to a valid parse.
                 The predicted alt is the min(ambigAlts)
input – The input token stream
startIndex – The start index for the current prediction
stopIndex – The index at which the ambiguity was identified during
prediction
fullCtx – true if the ambiguity was identified during LL prediction; otherwise, false if the ambiguity was identified during SLL prediction/**
	 * Constructs a new instance of the {@link AmbiguityInfo} class with the
	 * specified detailed ambiguity information.
	 *
	 * @param decision The decision number
	 * @param configs The final configuration set identifying the ambiguous
	 * alternatives for the current input
	 * @param ambigAlts The set of alternatives in the decision that lead to a valid parse.
	 *                  The predicted alt is the min(ambigAlts)
	 * @param input The input token stream
	 * @param startIndex The start index for the current prediction
	 * @param stopIndex The index at which the ambiguity was identified during
	 * prediction
	 * @param fullCtx {@code true} if the ambiguity was identified during LL
	 * prediction; otherwise, {@code false} if the ambiguity was identified
	 * during SLL prediction
	 */
	public AmbiguityInfo(int decision,
						 ATNConfigSet configs,
						 BitSet ambigAlts,
						 TokenStream input, int startIndex, int stopIndex,
						 boolean fullCtx)
	{
		super(decision, configs, input, startIndex, stopIndex, fullCtx);
		this.ambigAlts = ambigAlts;
	}
}