61 lines
2.9 KiB
TypeScript
61 lines
2.9 KiB
TypeScript
/*!
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* Copyright 2016 The ANTLR Project. All rights reserved.
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* Licensed under the BSD-3-Clause license. See LICENSE file in the project root for license information.
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*/
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import { BitSet } from "../misc/BitSet";
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import { DecisionEventInfo } from "./DecisionEventInfo";
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import { SimulatorState } from "./SimulatorState";
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import { TokenStream } from "../TokenStream";
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/**
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* This class represents profiling event information for an ambiguity.
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* Ambiguities are decisions where a particular input resulted in an SLL
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* conflict, followed by LL prediction also reaching a conflict state
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* (indicating a true ambiguity in the grammar).
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*
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* This event may be reported during SLL prediction in cases where the
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* conflicting SLL configuration set provides sufficient information to
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* determine that the SLL conflict is truly an ambiguity. For example, if none
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* of the ATN configurations in the conflicting SLL configuration set have
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* traversed a global follow transition (i.e.
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* {@link ATNConfig#getReachesIntoOuterContext} is `false` for all
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* configurations), then the result of SLL prediction for that input is known to
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* be equivalent to the result of LL prediction for that input.
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*
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* In some cases, the minimum represented alternative in the conflicting LL
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* configuration set is not equal to the minimum represented alternative in the
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* conflicting SLL configuration set. Grammars and inputs which result in this
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* scenario are unable to use {@link PredictionMode#SLL}, which in turn means
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* they cannot use the two-stage parsing strategy to improve parsing performance
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* for that input.
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*
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* @see ParserATNSimulator#reportAmbiguity
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* @see ParserErrorListener#reportAmbiguity
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*
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* @since 4.3
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*/
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export declare class AmbiguityInfo extends DecisionEventInfo {
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/** The set of alternative numbers for this decision event that lead to a valid parse. */
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private ambigAlts;
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/**
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* Constructs a new instance of the {@link AmbiguityInfo} class with the
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* specified detailed ambiguity information.
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*
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* @param decision The decision number
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* @param state The final simulator state identifying the ambiguous
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* alternatives for the current input
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* @param ambigAlts The set of alternatives in the decision that lead to a valid parse.
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* The predicted alt is the min(ambigAlts)
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* @param input The input token stream
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* @param startIndex The start index for the current prediction
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* @param stopIndex The index at which the ambiguity was identified during
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* prediction
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*/
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constructor(decision: number, state: SimulatorState, ambigAlts: BitSet, input: TokenStream, startIndex: number, stopIndex: number);
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/**
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* Gets the set of alternatives in the decision that lead to a valid parse.
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*
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* @since 4.5
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*/
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get ambiguousAlternatives(): BitSet;
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}
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