[antlr-interest] Nondeterminism between alts 1 and 2 of block...

[Thiago F.G. Albuquerque]

At 22:22 18/05/03 -0700, you wrote:
>For now, I'd use syntactic predicates...

I fixed it like this:

I set k=1 in the parser and modified the grammar:

exp : ID ("(") => func_call
       | (variable "=") => assignment
       | logical_exp
       ;

Nondeterminism errors appeared in lots of other places in the grammar, but 
all of them could be corrected in the same way.

Thank you, for your help, Terrence. I am sorry if I seemed a bit rude in my 
previous message.

Thiago

>Terence
>
>On Sunday, May 18, 2003, at 02:42  PM, Thiago F.G. Albuquerque wrote:
>
> > At 13:14 18/05/03 -0700, you wrote:
> >> Hi.  You've correctly analyzed this as a Human. :)  Unfortunately, for
> >> the moment, ANTLR generates linear approximate k=2 lookahead not the
> >> real thing (which has sequence information).  This is a weakness of
> >> the
> >> parsing strategy not your understanding of LL(k).  Sorry.
> >>
> >> I'm actually working on the analysis stuff at the moment (full LL(k)
> >> and semantic predicate hoisting). :)
> >>
> >> Ter
> >
> > Ok, thank you for your answer. But how can I fix this? Is there a
> > workaround? I need to write my parser. This example I sent is a
> > simplification of a larger grammar I am working on (a project for
> > school).
> > Here's an excerpt of the original grammar:
> >
> > exp : func_call
> >        | (variable "=") => assignment
> >        | logical_exp
> >        ;
> >
> > logical_exp : rel_exp (("||" | "&&" | "!") rel_exp)*
> >              ;
> >
> > rel_exp : add_exp (rel_op add_exp)*
> >          ;
> >
> > rel_op : "<" | "<=" | ">" | ">=" | "==" | "!="
> >         ;
> >
> > add_exp : mul_exp (( "+" | "-") mul_exp)*
> >          ;
> >
> > mul_exp : atom (( "*" | "/" | "%" ) atom)*
> >          ;
> >
> > atom : const
> >       | variable
> >       | "(" exp ")"
> >       ;
> >
> > In this grammar I cannot colapse 'exp' and 'atom' into one rule.
> >
> > What should I do?
> >
> > TIA,
> > Thiago


 

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