Says tilly:

I should note that Dominus' solution suffers from exactly the bug that tsee is trying to work around, except worse because he didn't think carefully about what happens if $/ wants to do a greedy match across a block.

Now, now. You don't know whether I thought about it carefully; you were not there, and you cannot see into my brain. The code may be wrong, or broken, or whatever. But in my opinion, I did think carefully about it. And on this matter, my opinion is the only informed one.

(I already mentioned these issues to him.)

Yes, but not in a way I could understand. I asked you to clarify several points, but I did not receive any reply from you.

I think that providing a test case that demonstrated the problem would have been clearer and more helpful than what you did write either in private email or here. Unfortunately, if you have produced one, I have not seen it.

Update: OK, I've now seen the example you posted later on. Thanks very much for posting it. The example was indeed much clearer and more helpful than either of your earlier messages. Can I suggest that since what you were doing here was essentially the same as reporting a bug, that the usual rules of good practice in bug reporting should apply? The test case was a lot more useful than any amount of additional verbiage would have been.

Thanks again. I will try to repair this bug before the book is published.