[antlr-interest] Re: wierdness - or perhaps my ignorance

[genericised]

That doesn't work.  I was under the impression that the
rule didn't need to be anything, because it was set as
the filter for the lexer with options { filter=blah; }.

A filter has to be protected.  The same output occurs
if a filter is specified or not and the rule is protected,
or not, if the rule contains a dot, the rule is not protected 
and no filter is used and if the token type is set or not.

Davy 

--- In antlr-interest at y..., Bogdan Mitu <bogdan_mt at y...> wrote:
> Hi Davy,
>  
> First of all, protected rules don't return any token. Second, if 
you set the
> token type to SKIP, lexer won't output it. Third, if the rule is 
empty, it
> won't consume any char. Try:
> 
> BLAH    :  .    // Note the dot, which means "anything"
>         {  System.out.println("ignoring: "+ $getText); } 
>         ;
> 
> Bogdan
> 
> --- genericised <trigonometric at s...> wrote:
> > class SillyLexer extends Lexer;
> > options { filter=BLAH; }
> > 
> > protected BLAH    : { 
> >   $setType(Token.SKIP);
> >   System.out.println("ignoring: "+getText());
> > } ;
> > ---------------------------------------------------
> > 
> > called from a main like so:
> > 
> > ---------------------------------------------------
> > while(true) {
> >    try {
> >       sillyLexer.nextToken();   
> >    } catch(Exception e) {}
> > }
> > ---------------------------------------------------
> > 
> > when executed, no output is generated and
> > the lexer gets stuck in an infinate loop, why?
> > 
> > I comprehend that if newlines were an issue I
> > would have to catch them otherwise the lexer
> > would be stuck on one line, but here input is
> > from stdin so newlines should not be an issue?
> > 
> > Note: I am not trying to achieve anything specific
> > here, I am just curious.
> > 
> > Davy
> > 
> > 
> >  
> > 
> > Your use of Yahoo! Groups is subject to 
http://docs.yahoo.com/info/terms/ 
> > 
> > 
> > 
> 
> 
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