Benchmark: timing 10 iterations of chars, i...
     chars: 40 wallclock secs (38.37 usr +  0.04 sys = 38.41 CPU) @  0.26/s (n=10)
         i: 12 wallclock secs (11.43 usr +  0.01 sys = 11.44 CPU) @  0.87/s (n=10)
      s/iter chars     i
chars   3.84    --  -70%
i       1.14  236%    --