Benchmark: timing 1000 iterations of do, golf, st...
        do:  8 wallclock secs ( 4.00 usr +  4.21 sys =  8.21 CPU) @ 121.80/s (n=1000)
      golf: 74 wallclock secs (20.15 usr + 53.05 sys = 73.20 CPU) @ 13.66/s (n=1000)
        st: 34 wallclock secs (18.96 usr + 14.01 sys = 32.97 CPU) @ 30.33/s (n=1000)
       Rate golf   st   do
golf 13.7/s   -- -55% -89%
st   30.3/s 122%   -- -75%
do    122/s 792% 302%   --