[antlr-interest] Architectural Suggestion: Pluggable ErrorReporting

[Vladimir Gusev]

As far as I remember, the error output behaviour is overridable via grammar
file. This is how I do it in the parser part:

....
  private ErrorReporter errorReporter;

	public CalcParser(TokenStream lexer, ErrorReporter errorReporter) {
	  this(lexer, 4);
	  this.errorReporter = errorReporter;
	}

	public void reportError(RecognitionException e) {
		errorReporter.reportError(e.getMessage(),
                                   e.getLine(),
                                   e.getColumn());
	}

   }
.....
ErrorReporter is a simple adapter which does arbitrary error output.

Vladimir


-----Original Message-----
From: antlr-interest-bounces at antlr.org
[mailto:antlr-interest-bounces at antlr.org] On Behalf Of David Holroyd
Sent: Wednesday, April 25, 2007 3:28 PM
To: antlr-interest at antlr.org
Subject: Re: [antlr-interest] Architectural Suggestion: Pluggable
ErrorReporting

On Wed, Apr 25, 2007 at 02:30:46PM -0400, Marc-Andr? Laverdi?re wrote:
> Maybe the error reporting logic could be delegated to an overridable 
> BaseErrorDisplayer class. The BaseRecognizer would have a set/get pair 
> to deal with it. It would not have much performance overhead and would 
> give us some customization for people like me who would like to report 
> directly to a GUI.

+1

Though I'd go for ErrorDisplayer interface, and maybe an
ErrorDisplayer.DEFAULT instance that sends to stderr, as currently.


ta,
dave

--
http://david.holroyd.me.uk/