[Libguestfs] [PATCH 0/2] Add lightweight bindings for PCRE.

[Richard W.M. Jones]

On Wed, Aug 02, 2017 at 03:01:53PM +0200, Pino Toscano wrote:
> On Wednesday, 2 August 2017 13:52:06 CEST Richard W.M. Jones wrote:
> > I think you're suggesting this:
> > 
> >   let m = PCRE.exec re "ccaaaabb" in
> >   if PCRE.matches m then (
> >     let whole = PCRE.sub m 0 in
> 
> Not really, my suggestion was to have a separate object representing
> the result of a regex match -- much like other language have in their
> regex APIs.
> 
> OTOH, this solution LGTM as well: the result of the regex is not saved
> in a thread-local variable, but directly in the same regex object, so
> can be kept/used around, and it is GC'ed when not needed anymore.
> If you could apply that change, that'd be a LGTM.

But the problem still is this makes the if/else chains more awkward.

What's really wrong with the thread-local variable?  It only stores a
single string and a vector of integers per thread (at most).  The
final string/vector is reliably freed on exit - I know that because
I've checked it with valgrind.

Rich.

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