Benchmark: timing 100 iterations of html, join, local, manual...
      html:  7 wallclock secs ( 6.36 usr +  0.01 sys =  6.37 CPU) @ 15.70/s (n=100)
      join: 22 wallclock secs (22.27 usr +  0.01 sys = 22.28 CPU) @  4.49/s (n=100)
     local: 22 wallclock secs (22.46 usr +  0.02 sys = 22.48 CPU) @  4.45/s (n=100)
    manual: 76 wallclock secs (75.38 usr +  0.01 sys = 75.39 CPU) @  1.33/s (n=100)