[antlr-interest] Please help with a grammar issue
Indhu Bharathi
indhu.b at s7software.com
Fri Oct 30 09:36:06 PDT 2009
Maybe you can use validating semantic predicate
r
@init {
int cntA=0, cntB=0, cntC=0;
}
: ( a {cntA++;} | b {cntB++;} | c {cntC++;} )+ {cntA>1 && cntB<=1 && cntC==1}?
;
Cheers, Indhu
S7 Software
From: antlr-interest-bounces at antlr.org [mailto:antlr-interest-bounces at antlr.org] On Behalf Of Frank Du
Sent: Friday, October 30, 2009 9:53 PM
To: 'antlr-interest at antlr.org'
Subject: [antlr-interest] Please help with a grammar issue
Dear All,
I have a grammar issue and need your help. Let’s say I have tree rules: a, b, c
Rule a occurs multiple times, rule b occurs one time or none, and rule c occurs one time.
My question is: How to write the grammar, so the rule ordering is arbitrary?
Thank you so much! Have a nice day!
Best Regards,
Frank
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