[antlr-interest] collecting tokens without invoking parser rules...

[Jim Idle]

Did you not see that I posted this as the solution to you last week?

Jim

> -----Original Message-----
> From: antlr-interest-bounces at antlr.org [mailto:antlr-interest-
> bounces at antlr.org] On Behalf Of Alan Lehotsky
> Sent: Tuesday, January 18, 2011 4:16 PM
> To: antlr-interest at antlr.org
> Cc: Alan Lehotsky
> Subject: Re: [antlr-interest] collecting tokens without invoking parser
> rules...
>
> > From: "Alan Lehotsky" <ALehotsky at ABINITIO.COM>
> > Date: January 17, 2011 4:40:02 PM EST
> > To: antlr-interest at antlr.org
> > Subject: [antlr-interest] collecting tokens without invoking parser
> rules...
> >
> >
> > Using Antlr 3.2 with language=C as a target
> >
> > For parsing Teradata's stored-procedure language (SPL), we have the
> > issue of context-sensitive token hiding.
> >
> > I'm trying to use rules for SQL statements embedded in SPL that just
> > swallow the tokens, so we have rules like:
> >
> >
> >        swallow_to_semi :   ~ (  SEMI  ) * ;
> >
> >                update_stmt :  UPDATE swallow_to_semi;
> >
> > .......
> > This feels like something that should be relatively easy to do, but I
> > don't seem to be able to figure out exactly how to make it happen and
> > I haven't hit upon the right search terms to find an appropriate
> > example in the Antlr-interest archives or the Wiki.
>
>
> Answering my own question...
>
> It turns out that I was trying TOO hard to make this work.  This simple
> rule seems to completely resolve the problems I was having:
>
>
> 	swallow_to_semi :
>
>                      ( { LT(1)->getType(LT(1)) != SEMI }?.)+
>
> i.e. collect any token that ISN'T a SEMI.  Not sure why the original
> rule didn't do exactly the same thing, but this doesnt get confused by
> trying to do any parser-rule reductions on the token stream.
>
>
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