[Patch] Support assertions and greedy/ungreedy matching in regex

[Paolo Carlini]

Hi,

On 09/12/2013 03:25 PM, Tim Shen wrote:
> This patch implement the (expecting) last two features in regex. Work
> is easier after this ;)
Great. A quick-quick comment: if these are the last two features, why we 
can't un-xfail the testcase which we added latety? Also, a grep revealed 
a couple more xfails. Can you clarify?

Also, much more generally, I would be curious about the remaining work: 
I think essentially it boils down to the vagaries for the other 
non-default regex dialects? Is it a lot of work?

Thanks a lot for now, awaiting more comments,
Paolo.