/^$alpha$alnum+$/ : 20 wallclock secs (20.41 usr + 0.00 sys = 20.41 CPU) @ 4.90/s (n=100) /^$alpha$alnum+$/o: 9 wallclock secs ( 8.34 usr + 0.00 sys = 8.34 CPU) @ 11.99/s (n=100) /$qr/ : 9 wallclock secs ( 9.59 usr + 0.00 sys = 9.59 CPU) @ 10.43/s (n=100) $qr : 10 wallclock secs ( 9.94 usr + 0.00 sys = 9.94 CPU) @ 10.06/s (n=100) /$qr/o : 9 wallclock secs ( 8.34 usr + 0.01 sys = 8.35 CPU) @ 11.98/s (n=100)