[antlr-interest] ANTLR C# port

[Dilip Ranganathan]

I may have miscommunicated something here. I have a very simple "Hello
World!" style grammar that I wrote to learn ANTLR. I deliberately fed the
lexer/parser wrong input to see what happens. I can see this exception being
caught by the parser (I forced the debugger to break into this exception by
explicitly listing this exception under Debug->Exceptions list in VS2010).
But the outer client code that fires off the parser (using ANTLRStringStream
and friends) is bracketed by try/catch blocks but never gets anything. This
probably makes sense if library code is eating those exceptions but if it
does, how can client code know something went wrong?


On Thu, May 19, 2011 at 5:52 AM, Sam Harwell <sharwell at pixelminegames.com>wrote:

> My initial guess is the exceptions are being thrown in the lexer. By
> default, the implementation of NextToken in the lexer catches any
> RecognitionException and handles it by skipping the invalid token. Custom
> handling of the exception depends on exactly what you're trying to
> accomplish. One way to start is adding the following rule to the end of
> your
> lexer, which passes the invalid tokens to the lexer for handling.
>
> INVALID_CHAR : . ;
>
> Sam
>
> -----Original Message-----
> From: antlr-interest-bounces at antlr.org
> [mailto:antlr-interest-bounces at antlr.org] On Behalf Of Dilip Ranganathan
> Sent: Wednesday, May 18, 2011 3:00 AM
> To: antlr-interest at antlr.org
> Subject: [antlr-interest] ANTLR C# port
>
> Hi
>
> I have been banging my head with Sam Harwell's Antlr C# port since morning.
>
> SO far I have managed to integrate grammar compilation with Visual Studio
> 2010 following the instructions on this page:
> http://www.antlr.org/wiki/display/ANTLR3/Antlr3CSharpReleases
>
> However I am stuck with something for the moment. A simple test driver
> program I wrote to test the generated lexer/parser doesn't report any kind
> of error when I pass invalid input. That is, the generated parser code is
> eating the exception and the output window only shows that a few first
> chance exceptions were generated. Now I added these exceptions to
> Debug->Exceptions list in VS 2010 (under CLR) and that way I was able to
> make the debugger break into the offending code but I can't believe this is
> the way to do it? Shouldn't I be seeing something on the console or at
> least
> as an exception I must be able to catch and display exactly what was wrong
> with my input?
>
> List: http://www.antlr.org/mailman/listinfo/antlr-interest
> Unsubscribe:
> http://www.antlr.org/mailman/options/antlr-interest/your-email-address
>
>