[antlr-interest] Potential gotcha - could it be warned?

[Steve Bennett]

I just spent the last hour tracking down one stupid error in my code:
a rule that looked like this:

foo:  (| bar);

It was enough to make the debugger fail on any input, and go into an
infinite loop upon pressing the "back" button.

Perhaps ANTLRWorks could detect this kind of rule and either warn or
refuse to compile?

Steve