[antlr-interest] ANTLR 3 using k=0, any info on doing this?

The Researcher researcher0x00 at gmail.com
Wed Mar 2 18:00:31 PST 2011


{{...}} syntax doesn't ring a bell. I would like to understand it, but can
find nothing on it.
Any references or wiki pages?

Thanks.


On Wed, Mar 2, 2011 at 1:37 PM, Terence Parr <parrt at cs.usfca.edu> wrote:

> Syntactic predicates can only execute actions that can be undone or that
> have no side effects. to specify such a special action, use {{...}} :) In
> general though {...}?=> should be for Boolean that say things like "Allow
> GCC extensions".
> Ter
>  On Mar 2, 2011, at 10:31 AM, The Researcher wrote:
>
> > Ter
> >
> > Thanks, they work great, but then I run into what I believe is the
> "Trouble
> > with syntactic predicates that reference semantic predicates that rely on
> a
> > current dynamic attribute scope" which is why I have asked Sam about
> > @scopeinit. I can get around it, but it doesn't seem intuitive.
> >
> > If you are anyone else wants me to keep an eye open for certain things
> while
> > writing this grammar, just ask.
> >
> > I do have several suggestions in the work, but want to have a working
> > grammar for at least the PE Image before any write-up, then move onto the
> > .text section which is where it will get really interesting.
> >
> > Eric
> >
> > On Wed, Mar 2, 2011 at 1:16 PM, Terence Parr <parrt at cs.usfca.edu> wrote:
> >
> >> Use {...}?=> for this.It forces the predicates to be tested regardless
> of
> >> whether or not the lookahead predicts an alternative.
> >>
> >> Ter
> >> On Feb 28, 2011, at 6:12 PM, The Researcher wrote:
> >>
> >>> I tried searching the interest group with k=0 but that wasn't
> productive,
> >>> and Google doesn't do any better.
> >>>
> >>> Yes I know setting k=0 is not what one normally if ever does with
> ANTLR,
> >> but
> >>> I am researching what it will take to get ANTLR to validate a Microsoft
> >>> Common Language Infrastructure file. I did write a separate validator
> by
> >>> hand and that works great.
> >>>
> >>> One of my goals out of this is to have a way to write binary file
> readers
> >>> and validators using ANTLR. Yes I know that I will have to modify
> ANTLR.g
> >> to
> >>> do this correctly, but before that, I have to know what the current
> >> ANTLR.g
> >>> is capable of doing and what needs to be modified or enhanced.
> >>>
> >>> So far I have only fond the ANTLR 2 Java .class file reader by Andreas
> >>> Rueckert and the few mentions of using Bytes in "Definitive ANTLR
> >>> Reference". I am getting the other book.
> >>>
> >>> Using gated semantic predicates is working out great, but ANTLR is
> >>> determined to check for multiple alternatives. I was hoping that K=0
> >> would
> >>> shut that whole process down  and using the gated semantic predicates
> to
> >>> dynamically shut off the options would leave ANTLR not trying
> >> alternatives.
> >>>
> >>> Any clues or references are welcome.
> >>>
> >>> Thanks Eric
> >>>
> >>> List: http://www.antlr.org/mailman/listinfo/antlr-interest
> >>> Unsubscribe:
> >> http://www.antlr.org/mailman/options/antlr-interest/your-email-address
> >>
> >>
> >> List: http://www.antlr.org/mailman/listinfo/antlr-interest
> >> Unsubscribe:
> >> http://www.antlr.org/mailman/options/antlr-interest/your-email-address
> >>
> >
> > List: http://www.antlr.org/mailman/listinfo/antlr-interest
> > Unsubscribe:
> http://www.antlr.org/mailman/options/antlr-interest/your-email-address
>
>
> List: http://www.antlr.org/mailman/listinfo/antlr-interest
> Unsubscribe:
> http://www.antlr.org/mailman/options/antlr-interest/your-email-address
>


More information about the antlr-interest mailing list