[antlr-interest] How to do "not" in a syntactic predicate?

[Indhu Bharathi]

Try something like:

 

(a)=> ((b)=>/*nothing*/ | a)

 

I remember facing similar problem. I guess you can't use '~' in a syntactic
predicate.

 

 

From: antlr-interest-bounces at antlr.org
[mailto:antlr-interest-bounces at antlr.org] On Behalf Of Naveen Chawla
Sent: Monday, October 05, 2009 7:32 PM
To: antlr-interest at antlr.org
Subject: [antlr-interest] How to do "not" in a syntactic predicate?

 

If I do

 

(a ~b)=> a

 

meaning "take this alternative if you encounter an a when not followed by b"

 

I get a syntax error: unexpected token b

Is it the right syntax to use '~'?

 

N

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