[antlr-interest] Fwd: Simple question, Hard answer?

Gavin Lambert antlr at mirality.co.nz
Wed Sep 3 14:13:49 PDT 2008


At 23:13 3/09/2008, Kausch, Robert wrote:
 >You can ignore tokens by sending them on a different channel. 
The
 >following grammar ignores everything that is not 'okko' and 
works
 >for me:
 >
 >grammar test;
 >
 >start: (T1)*;
 >
 >T1:	'okko';
 >T2:	~(T1) { $channel = HIDDEN; } ;

T1 is a sequence.  ~ is intended to operate on sets (alternatives 
of single characters/tokens).  Odd things happen if you try to use 
~ on a sequence.  (It does actually compile, but it doesn't run 
properly.)

Using "T2: .;" ought to work, though.  Or just making it a 
filtering lexer.



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