antlr4ng
Version:
Alternative JavaScript/TypeScript runtime for ANTLR4
148 lines (147 loc) • 7.87 kB
TypeScript
import { type Parser } from "./Parser.js";
import { type RecognitionException } from "./RecognitionException.js";
import { type Recognizer } from "./Recognizer.js";
import { type ATNConfigSet } from "./atn/ATNConfigSet.js";
import { type DFA } from "./dfa/DFA.js";
import { type ATNSimulator } from "./atn/ATNSimulator.js";
import { type Token } from "./Token.js";
import { type BitSet } from "./misc/BitSet.js";
/** How to emit recognition errors. */
export interface ANTLRErrorListener {
/**
* Upon syntax error, notify any interested parties. This is not how to
* recover from errors or compute error messages. {@link ANTLRErrorStrategy}
* specifies how to recover from syntax errors and how to compute error
* messages. This listener's job is simply to emit a computed message,
* though it has enough information to create its own message in many cases.
*
* The {@link RecognitionException} is non-null for all syntax errors except
* when we discover mismatched token errors that we can recover from
* in-line, without returning from the surrounding rule (via the single
* token insertion and deletion mechanism).
*
* @param recognizer
* What parser got the error. From this
* object, you can access the context as well
* as the input stream.
* @param offendingSymbol
* The offending token in the input token
* stream, unless recognizer is a lexer (then it's null). If
* no viable alternative error, `e` has token at which we
* started production for the decision.
* @param line
* The line number in the input where the error occurred.
* @param charPositionInLine
* The character position within that line where the error occurred.
* @param msg
* The message to emit.
* @param e
* The exception generated by the parser that led to
* the reporting of an error. It is null in the case where
* the parser was able to recover in line without exiting the
* surrounding rule.
*/
syntaxError<S extends Token, T extends ATNSimulator>(recognizer: Recognizer<T>, offendingSymbol: S | null, line: number, charPositionInLine: number, msg: string, e: RecognitionException | null): void;
/**
* This method is called by the parser when a full-context prediction results in an ambiguity.
*
* Each full-context prediction which does not result in a syntax error
* will call either {@link reportContextSensitivity} or {@link reportAmbiguity}.
*
* When `ambigAlts` is not null, it contains the set of potentially
* viable alternatives identified by the prediction algorithm. When
* `ambigAlts` is null, use {@link ATNConfigSet#getAlts} to obtain the
* represented alternatives from the `configs` argument.
*
* When `exact` is `true`, *all* of the potentially
* viable alternatives are truly viable, i.e. this is reporting an exact
* ambiguity. When `exact` is `false`, *at least two* of
* the potentially viable alternatives are viable for the current input, but
* the prediction algorithm terminated as soon as it determined that at
* least the *minimum* potentially viable alternative is truly
* viable.
*
* When the {@link PredictionMode.LL_EXACT_AMBIG_DETECTION} prediction
* mode is used, the parser is required to identify exact ambiguities so
* `exact` will always be `true`.
*
* This method is not used by lexers.
*
* @param recognizer the parser instance
* @param dfa the DFA for the current decision
* @param startIndex the input index where the decision started
* @param stopIndex the input input where the ambiguity was identified
* @param exact `true` if the ambiguity is exactly known, otherwise
* `false`. This is always `true` when
* {@link PredictionMode.LL_EXACT_AMBIG_DETECTION} is used.
* @param ambigAlts the potentially ambiguous alternatives, or `null`
* to indicate that the potentially ambiguous alternatives are the complete
* set of represented alternatives in `configs`
* @param configs the ATN configuration set where the ambiguity was
* identified
*/
reportAmbiguity(recognizer: Parser, dfa: DFA, startIndex: number, stopIndex: number, exact: boolean, ambigAlts: BitSet | undefined, configs: ATNConfigSet): void;
/**
* This method is called when an SLL conflict occurs and the parser is about
* to use the full context information to make an LL decision.
*
* If one or more configurations in `configs` contains a semantic
* predicate, the predicates are evaluated before this method is called. The
* subset of alternatives which are still viable after predicates are
* evaluated is reported in `conflictingAlts`.
*
* This method is not used by lexers.
*
* @param recognizer the parser instance
* @param dfa the DFA for the current decision
* @param startIndex the input index where the decision started
* @param stopIndex the input index where the SLL conflict occurred
* @param conflictingAlts The specific conflicting alternatives. If this is
* `null`, the conflicting alternatives are all alternatives
* represented in `configs`. At the moment, conflictingAlts is non-null
* (for the reference implementation, but Sam's optimized version can see this
* as null).
* @param configs the ATN configuration set where the SLL conflict was
* detected
*/
reportAttemptingFullContext(recognizer: Parser, dfa: DFA, startIndex: number, stopIndex: number, conflictingAlts: BitSet | undefined, configs: ATNConfigSet): void;
/**
* This method is called by the parser when a full-context prediction has a
* unique result.
*
* Each full-context prediction which does not result in a syntax error
* will call either {@link reportContextSensitivity} or
* {@link #reportAmbiguity}.
*
* For prediction implementations that only evaluate full-context
* predictions when an SLL conflict is found (including the default
* {@link ParserATNSimulator} implementation), this method reports cases
* where SLL conflicts were resolved to unique full-context predictions,
* i.e. the decision was context-sensitive. This report does not necessarily
* indicate a problem, and it may appear even in completely unambiguous
* grammars.
*
* `configs` may have more than one represented alternative if the
* full-context prediction algorithm does not evaluate predicates before
* beginning the full-context prediction. In all cases, the final prediction
* is passed as the `prediction` argument.
*
* Note that the definition of "context sensitivity" in this method
* differs from the concept in {@link DecisionInfo.contextSensitivities}.
* This method reports all instances where an SLL conflict occurred but LL
* parsing produced a unique result, whether or not that unique result
* matches the minimum alternative in the SLL conflicting set.
*
* This method is not used by lexers.
*
* @param recognizer the parser instance
* @param dfa the DFA for the current decision
* @param startIndex the input index where the decision started
* @param stopIndex the input index where the context sensitivity was
* finally determined
* @param prediction the unambiguous result of the full-context prediction
* @param configs the ATN configuration set where the unambiguous prediction
* was determined
*/
reportContextSensitivity(recognizer: Parser, dfa: DFA, startIndex: number, stopIndex: number, prediction: number, configs: ATNConfigSet): void;
}