[antlr-interest] Problems with first example

John B. Brodie jbb at acm.org
Mon Dec 21 06:30:08 PST 2009


Greetings!
On Mon, 2009-12-21 at 09:08 -0500, Bill Ramsay wrote:
> Hello,
> 
> I'm new to Antlr and am trying to work through the Definitive Guide.   I can't seem to get the first example to work.
> I create the .g file and lexer and parser classes fine.   I compile my example test program fine.   And it runs fine.  Except for one minor problem - it doesn't work.   I put a few debug lines in the code and  it gets hung up on the line:
> 
>     ANTLRInputStream input = new ANTLRInputStream(System.in);
> 
> It never seems to move past this line.   The code used is copied from the book,page 10 - 12.    

System.in is java-speak for the standard input device which, unless you
have redirected it, is your keyboard.

So this line is establishing a I/O connection with the keyboard in order
to read in text to be parsed.

It would seem that everything is working just fine.

You simply need to type some text into your keyboard so that the example
grammar may parse it for you (or re-direct stdin to a disk file).

Hope this helps...
   -jbb




More information about the antlr-interest mailing list