or download this
Benchmark: timing 1000000 iterations of regex, unpack, xeger...
regex: 6 wallclock secs ( 5.71 usr + 0.00 sys = 5.71 CPU) @ 17
+5131.35/s (n=1000000)
unpack: 7 wallclock secs ( 5.91 usr + 0.00 sys = 5.91 CPU) @ 16
+9204.74/s (n=1000000)
xeger: 9 wallclock secs ( 9.26 usr + 0.00 sys = 9.26 CPU) @ 10
+7991.36/s (n=1000000)