[antlr-interest] grammar and rewrite rule problem (newbie)

[ali azimi]

Hi, 
   
  Thank you very much for replying to my post. For simplicity I have left them empty as the rule is quite large and I thought not to bother you guys. I thought the problem was the * sign in the rule but it was not. 
   
  I have sorted out the looping problem. However a problem still remains and that is how to write the rewrite rule. Could you please suggest me a rewrite rule for the following? 
   
  r:  a  ( c | d )*  ( e | f )? g
;
   
  Many thanks in advance.
   
  Best wishes,
   
  Al


Gavin Lambert <antlr at mirality.co.nz> wrote:  At 05:40 20/07/2007, ali azimi wrote:
  How can rules like the following ( r ) be dealt with without producing an infinite loop? Can you also tell me what the rewrite rule for it should look like?
 
Grammar T;
 
r:  a  ( c | d )*  ( e | f )? g  
;
 
a:
;
 
c:
;
e:
;
f:
;
g:
;
Don't write empty rules -- trying to match multiple instances of nothing at all is an instant infinite loop. 

       
---------------------------------
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