[antlr-interest] ab? b?a

[fat bold cyclop]

Thanks for the answer.
> The WS makes sense separating move no. 1 from move no. 2, and may be
> ignored in the parser actions.
I could switch off ignoring WS but it forces me to put WS in many
places of my grammar, making less readable. That's because there are
lots of places I shoud also put WS in my grammar.
Besides I'd love to learn new tricks, if there are any for this situation.

Of course, if I find nothing else, I'll go for your solution.

Regards,
fbc