[antlr-interest] Invalid option: backtrack

Terence Parr parrt at cs.usfca.edu
Tue Jul 22 11:02:54 PDT 2008


Hi class lexer... is v2 notation.
Ter
On Jul 22, 2008, at 10:57 AM, Laura Adam wrote:

> Hello,
>
> I'd like to make a try with the backtrack option.I want to turn on  
> the backtrack option at the grammar level.
> I made a lexer.g file like that :
>
>
> class lexer extends Lexer;
> options {
>    k=100;
>    backtrack = true;
>    }
> rules.............
>
>
>
> I had an "Invalid option: backtrack".
> (Moreover, if I try to change the first line into a "grammar T;",  
> trying to do exactly what I read in the book, that doesn't work, I  
> don't understand why)
>
> I reinstall the latest version of Antlr to be sure that I am using  
> one that contains that option.
> I also add to the classpath the .jar file such as that :
>
> export CLASSPATH="$CLASSPATH:/home/ladam.local/antlr-3.1b2/lib/ 
> antlr-3.1b2.jar:\
> /home/ladam.local/antlr-3.1b2/lib/stringtemplate-3.2.jar:\
> /home/ladam.local/antlr-3.1b2/lib/antlr-2.7.7.jar:\
> /home/ladam.local/antlr-3.1b2/lib/antlr-runtime-3.1b2.jar:\
> /home/ladam.local/antlr-3.1b2/lib/gunit-1.0.2.jar"
>
>
> Even if I want to use the backtrack option at a rule level, I can't.  
> Backtrack doesn't even appear in emacs ANTLR menu.
>
> What can I do?
>
> Laura Adam



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