antlr4ts/atn/PredictionMode.d.ts

ANTLR 4 runtime for JavaScript written in Typescript

/*!
 * Copyright 2016 The ANTLR Project. All rights reserved.
 * Licensed under the BSD-3-Clause license. See LICENSE file in the project root for license information.
 */
import { ATNConfigSet } from "./ATNConfigSet";
/**
 * This enumeration defines the prediction modes available in ANTLR 4 along with
 * utility methods for analyzing configuration sets for conflicts and/or
 * ambiguities.
 */
export declare enum PredictionMode {
    /**
     * The SLL(*) prediction mode. This prediction mode ignores the current
     * parser context when making predictions. This is the fastest prediction
     * mode, and provides correct results for many grammars. This prediction
     * mode is more powerful than the prediction mode provided by ANTLR 3, but
     * may result in syntax errors for grammar and input combinations which are
     * not SLL.
     *
     * When using this prediction mode, the parser will either return a correct
     * parse tree (i.e. the same parse tree that would be returned with the
     * {@link #LL} prediction mode), or it will report a syntax error. If a
     * syntax error is encountered when using the {@link #SLL} prediction mode,
     * it may be due to either an actual syntax error in the input or indicate
     * that the particular combination of grammar and input requires the more
     * powerful {@link #LL} prediction abilities to complete successfully.
     *
     * This prediction mode does not provide any guarantees for prediction
     * behavior for syntactically-incorrect inputs.
     */
    SLL = 0,
    /**
     * The LL(*) prediction mode. This prediction mode allows the current parser
     * context to be used for resolving SLL conflicts that occur during
     * prediction. This is the fastest prediction mode that guarantees correct
     * parse results for all combinations of grammars with syntactically correct
     * inputs.
     *
     * When using this prediction mode, the parser will make correct decisions
     * for all syntactically-correct grammar and input combinations. However, in
     * cases where the grammar is truly ambiguous this prediction mode might not
     * report a precise answer for *exactly which* alternatives are
     * ambiguous.
     *
     * This prediction mode does not provide any guarantees for prediction
     * behavior for syntactically-incorrect inputs.
     */
    LL = 1,
    /**
     * The LL(*) prediction mode with exact ambiguity detection. In addition to
     * the correctness guarantees provided by the {@link #LL} prediction mode,
     * this prediction mode instructs the prediction algorithm to determine the
     * complete and exact set of ambiguous alternatives for every ambiguous
     * decision encountered while parsing.
     *
     * This prediction mode may be used for diagnosing ambiguities during
     * grammar development. Due to the performance overhead of calculating sets
     * of ambiguous alternatives, this prediction mode should be avoided when
     * the exact results are not necessary.
     *
     * This prediction mode does not provide any guarantees for prediction
     * behavior for syntactically-incorrect inputs.
     */
    LL_EXACT_AMBIG_DETECTION = 2
}
export declare namespace PredictionMode {
    /**
     * Checks if any configuration in `configs` is in a
     * {@link RuleStopState}. Configurations meeting this condition have reached
     * the end of the decision rule (local context) or end of start rule (full
     * context).
     *
     * @param configs the configuration set to test
     * @returns `true` if any configuration in `configs` is in a
     * {@link RuleStopState}, otherwise `false`
     */
    function hasConfigInRuleStopState(configs: ATNConfigSet): boolean;
    /**
     * Checks if all configurations in `configs` are in a
     * {@link RuleStopState}. Configurations meeting this condition have reached
     * the end of the decision rule (local context) or end of start rule (full
     * context).
     *
     * @param configs the configuration set to test
     * @returns `true` if all configurations in `configs` are in a
     * {@link RuleStopState}, otherwise `false`
     */
    function allConfigsInRuleStopStates(/*@NotNull*/ configs: ATNConfigSet): boolean;
}