Benchmark: timing 1000000 iterations of brackets, slash i...
  brackets: 24 wallclock secs (24.20 usr +  0.00 sys = 24.20 CPU) 
            @ 41322.31/s (n=1000000)
   slash i: 14 wallclock secs (13.47 usr +  0.00 sys = 13.47 CPU) 
            @ 74239.05/s (n=1000000)