StringBuilder version of java.util.regex.Matcher.append*

Jeremy Manson jeremymanson at
Wed Mar 19 17:51:14 UTC 2014

I'm told that the diff didn't make it.  I've put it in a Google drive


On Wed, Mar 19, 2014 at 10:41 AM, Jeremy Manson <jeremymanson at>wrote:

> Hi folks,
> We've had this internally for a while, and I keep meaning to bring it up
> here.  The Matcher class has a few public methods that take StringBuffers,
> and we've found it useful to add similar versions that take StringBuilders.
> It has two benefits:
> - Users don't have to convert from one to the other when they want to use
> the method in question.  The symmetry is nice.
> - The StringBuilder variants are faster (if lock optimizations don't kick
> in, which happens in the interpreter and the client compiler).  For
> interpreted / client-compiled code, we saw something like a 25% speedup on
> String.replaceAll(), which calls into this code.
> Any interest?  Diff attached.
> Jeremy

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