On Tue, Mar 21, 2017 at 7:09 PM, Paul Eggert <egg...@cs.ucla.edu> wrote: > John P. Linderman wrote: >> >> Using what is to me the more obvious [0-9] pattern takes almost 50 times >> as >> long as using the [[:digit:]] pattern. Seems very strange. > > > Thanks for reporting that. In general, patterns like [a-z] can be much > slower than [[:lower:]] due to poorly-thought-out POSIX interfaces. However, > [0-9] is a special case: we can optimize such patterns safely if both ends > are ASCII digits. I installed the attached patch to Gnulib to do that; it > fixes the performance glitch you noticed, at least for me.
Thank you, Paul. I confirmed that that solves it for me, too, with a multibyte locale. I didn't reproduce it initially because I was using LC_ALL=C.
