[antlr-interest] literals.

[aravind srinivasan]

You can try using syntactic predicate. I am not sure if that would be the correct way of 
doing it as i have just started using antlr.
  
...| ("instanceof") => "instanceof" { rel_op = JSToken.InstanceOf; }  
	| "in" { rel_op = JSToken.In; }   
        ;

Aravind.

-----Original Message-----
From: cesar octavio lopez nataren [mailto:cesar at ciencias.unam.mx]
Sent: Wednesday, December 10, 2003 6:01 AM
To: antlr-interest at yahoogroups.com
Subject: Re: [antlr-interest] literals.


On Wed, 2003-12-10 at 01:00, Oliver Zeigermann wrote:
> This looks like you need more lookahead, k=3 should do to distinguish 
> "in" from "instanceof".
> "in" : LA(1)=i, LA(2)=n, LA(3)=?
> "instance" : LA(1)=i, LA(2)=n, LA(3)=s

Hello Oliver:

Look, If I put:

relational_op returns [JSToken rel_op]
{ rel_op = JSToken.None; }
        : LESS_THAN { rel_op = JSToken.LessThan; }
        | GREATER_THAN { rel_op = JSToken.GreaterThan; }
        | LESS_EQ { rel_op = JSToken.LessThanEqual; }
        | GREATER_EQ { rel_op = JSToken.GreaterThanEqual; }
        | "instanceof" { rel_op = JSToken.InstanceOf; }           <<<---
	| "in" { rel_op = JSToken.In; }   <<<----
        ;
 
I get the message: jscript.g:573:11:     k==1:"in"

Note that on my lexer options I already have: k = 3

If I erase that and add the lexical rule

IN: "in";

I get: 

jscript.g: warning:lexical nondeterminism between rules IDENTIFIER and
IN upon
jscript-lexer-parser.g:     k==1:'i'
jscript-lexer-parser.g:     k==2:'n'
jscript-lexer-parser.g:     k==3:<end-of-token>

The definition of IDENTIFIER  that I have is:

IDENTIFIER
options { testLiterals = true; }
        : ('a'..'z' | 'A'..'Z') ('a'..'z' | 'A'..'Z' | '0'..'9')*
        ;

what can I do?

Thanks a lot for the help.

César

 

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ 



 

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/