[antlr-interest] Strange parse result

[Micha]

Am 16.01.2011 22:23, schrieb Mark Christiaens:
> I simplified my test case further.  The grammar is now:
> 
> grammar test_grammar;
> 
> start : t*;
> t: ASSIGN | NUM ;
> ASSIGN : ':=';
> //NUM : '0';
> NUM : '0' ':0'?;
> 
> I would expect this to be able to match the input
> 
> 0:=0
> 
> but it doesn't.  Changing the definition of NUM to the commented version and
> the grammar does match the input.

some lookahead may help:

ASSIGN: (':=')=> ':=' ;
NUM: '0' ( (':0')=>':0' )?;

 Michael