Benchmark: timing 10000 iterations of index, regex...
     index:  3 wallclock secs ( 3.52 usr +  0.00 sys =  3.52 CPU) @ 2840.91/s (n=10000)
     regex: 92 wallclock secs (91.44 usr +  0.00 sys = 91.44 CPU) @ 109.36/s (n=10000)