org.antlr.v4.runtime

Class ConsoleErrorListener

java.lang.Object

org.antlr.v4.runtime.ConsoleErrorListener

All Implemented Interfaces:

ANTLRErrorListener<Object>

public class ConsoleErrorListener
extends Object
implements ANTLRErrorListener<Object>

Author:

Sam Harwell

Field Summary

Fields

Modifier and Type	Field and Description
static ConsoleErrorListener	INSTANCE Provides a default instance of ConsoleErrorListener.

Constructor Summary

Constructors

Constructor and Description
ConsoleErrorListener()

Method Summary

Modifier and Type	Method and Description
<T> void	syntaxError(Recognizer<T,?> recognizer, T offendingSymbol, int line, int charPositionInLine, String msg, RecognitionException e) Upon syntax error, notify any interested parties.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

INSTANCE

public static final ConsoleErrorListener INSTANCE

Provides a default instance of ConsoleErrorListener.

Constructor Detail

ConsoleErrorListener

public ConsoleErrorListener()

Method Detail

syntaxError

public <T> void syntaxError(Recognizer<T,?> recognizer,
                            T offendingSymbol,
                            int line,
                            int charPositionInLine,
                            String msg,
                            RecognitionException e)

Upon syntax error, notify any interested parties. This is not how to recover from errors or compute error messages. 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 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).

This implementation prints messages to System.err containing the values of line, charPositionInLine, and msg using the following format.

 line line:charPositionInLine msg
 

Specified by:

syntaxError in interface ANTLRErrorListener<Object>

Parameters:

recognizer - What parser got the error. From this object, you can access the context as well as the input stream.

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.

line - The line number in the input where the error occurred.

charPositionInLine - The character position within that line where the error occurred.

msg - The message to emit.

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.