[antlr-interest] Breaking a loop

[John Green]

I've got a pre-existing language with a requirement like this:

    (    ( (io_opt)* state_end )=> (io_opt)* state_end {break;}
    |    .
    )*

Hopefully my question is obvious from the example. I need to break the loop when I hit a certain production. Until that production is reached, arbitrary tokens are consumed by the ".". Assuming {break;} is a bad hack, what's a good way to do this in Antlr?

Cheers,
john at joanju dot com