[Patch 1/2] Rewrite regex scanner

[Jonathan Wakely]

On 23 August 2013 15:44, Stephen M. Webb wrote:
> On 08/23/2013 10:04 AM, Tim Shen wrote:
>>
>> By the way, it seems to take surprisingly short time to review; after
>> all, it's a huge patch.
>
> I'm still compiling...

I didn't compile it myself, I assume Tim has already done that before
submitting it for review!  I just eyeballed it.

A lot of the changed lines are due to moving the code from on file to
another, and I didn't review the regex logic carefully, just
sanity-checked it.  I'd usually be more stringent, but given that the
existing <regex> is so barebones if the tests pass after this patch
then it's better than what we had before, so I'm happy for it to go
in.