Benchmark: timing 5000 iterations of guttros, naive, orcish, 
schwartzian...
 guttros: 14 wallclock secs 
  (14.10 usr +  0.00 sys = 14.10 CPU) @ 354.61/s (n=5000)
 naive:  0 wallclock secs 
  ( 0.04 usr +  0.00 sys =  0.04 CPU) @ 125000.00/s (n=5000)
 orcish:  1 wallclock secs 
  ( 0.04 usr +  0.00 sys =  0.04 CPU) @ 125000.00/s (n=5000)
 schwartzian: 26 wallclock secs 
  (25.70 usr +  0.03 sys = 25.73 CPU) @ 194.33/s (n=5000)