antlr4ts/ANTLRErrorStrategy.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 { Parser } from "./Parser";
import { Token } from "./Token";
import { RecognitionException } from "./RecognitionException";
/**
 * The interface for defining strategies to deal with syntax errors encountered
 * during a parse by ANTLR-generated parsers. We distinguish between three
 * different kinds of errors:
 *
 * * The parser could not figure out which path to take in the ATN (none of
 *   the available alternatives could possibly match)
 * * The current input does not match what we were looking for
 * * A predicate evaluated to false
 *
 * Implementations of this interface report syntax errors by calling
 * {@link Parser#notifyErrorListeners}.
 *
 * TODO: what to do about lexers
 */
export interface ANTLRErrorStrategy {
    /**
     * Reset the error handler state for the specified `recognizer`.
     * @param recognizer the parser instance
     */
    reset(/*@NotNull*/ recognizer: Parser): void;
    /**
     * This method is called when an unexpected symbol is encountered during an
     * inline match operation, such as {@link Parser#match}. If the error
     * strategy successfully recovers from the match failure, this method
     * returns the {@link Token} instance which should be treated as the
     * successful result of the match.
     *
     * This method handles the consumption of any tokens - the caller should
     * *not* call {@link Parser#consume} after a successful recovery.
     *
     * Note that the calling code will not report an error if this method
     * returns successfully. The error strategy implementation is responsible
     * for calling {@link Parser#notifyErrorListeners} as appropriate.
     *
     * @param recognizer the parser instance
     * @ if the error strategy was not able to
     * recover from the unexpected input symbol
     */
    recoverInline(/*@NotNull*/ recognizer: Parser): Token;
    /**
     * This method is called to recover from exception `e`. This method is
     * called after {@link #reportError} by the default exception handler
     * generated for a rule method.
     *
     * @see #reportError
     *
     * @param recognizer the parser instance
     * @param e the recognition exception to recover from
     * @ if the error strategy could not recover from
     * the recognition exception
     */
    recover(/*@NotNull*/ recognizer: Parser, /*@NotNull*/ e: RecognitionException): void;
    /**
     * This method provides the error handler with an opportunity to handle
     * syntactic or semantic errors in the input stream before they result in a
     * {@link RecognitionException}.
     *
     * The generated code currently contains calls to {@link #sync} after
     * entering the decision state of a closure block (`(...)*` or
     * `(...)+`).
     *
     * For an implementation based on Jim Idle's "magic sync" mechanism, see
     * {@link DefaultErrorStrategy#sync}.
     *
     * @see DefaultErrorStrategy#sync
     *
     * @param recognizer the parser instance
     * @ if an error is detected by the error
     * strategy but cannot be automatically recovered at the current state in
     * the parsing process
     */
    sync(/*@NotNull*/ recognizer: Parser): void;
    /**
     * Tests whether or not `recognizer` is in the process of recovering
     * from an error. In error recovery mode, {@link Parser#consume} adds
     * symbols to the parse tree by calling
     * {@link Parser#createErrorNode(ParserRuleContext, Token)} then
     * {@link ParserRuleContext#addErrorNode(ErrorNode)} instead of
     * {@link Parser#createTerminalNode(ParserRuleContext, Token)}.
     *
     * @param recognizer the parser instance
     * @returns `true` if the parser is currently recovering from a parse
     * error, otherwise `false`
     */
    inErrorRecoveryMode(/*@NotNull*/ recognizer: Parser): boolean;
    /**
     * This method is called by when the parser successfully matches an input
     * symbol.
     *
     * @param recognizer the parser instance
     */
    reportMatch(/*@NotNull*/ recognizer: Parser): void;
    /**
     * Report any kind of {@link RecognitionException}. This method is called by
     * the default exception handler generated for a rule method.
     *
     * @param recognizer the parser instance
     * @param e the recognition exception to report
     */
    reportError(recognizer: Parser, e: RecognitionException): void;
}