v1 is beating v2 most of the time, that's not good.

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━━━━┓
┃             Expression             ┃    Mean   ┃     Var     ┃   Ratio   ┃
┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╋━━━━━━━━━━━╋━━━━━━━━━━━━━╋━━━━━━━━━━━┫
┃   (example chain1/execute true 10) ┃ 294.73 µs ┃  ± 17.88 µs ┃   126.2 % ┃
┃   (example chain2/execute true 10) ┃ 233.47 µs ┃   ± 6.49 µs ┃   100.0 % ┃ (fastest)
┃   (example chain1/execute true 50) ┃ 278.71 µs ┃   ± 7.70 µs ┃   119.4 % ┃
┃   (example chain2/execute true 50) ┃   2.35 ms ┃ ± 127.43 µs ┃ 1,005.9 % ┃ (slowest)
┃  (example chain1/execute true 100) ┃ 237.70 µs ┃   ± 7.42 µs ┃   101.8 % ┃
┃  (example chain2/execute true 100) ┃   1.36 ms ┃ ± 620.82 µs ┃   581.7 % ┃
┃  (example chain1/execute false 10) ┃   1.20 ms ┃ ± 110.45 µs ┃   514.6 % ┃
┃  (example chain2/execute false 10) ┃   1.86 ms ┃  ± 59.25 µs ┃   798.8 % ┃
┃  (example chain1/execute false 50) ┃ 953.14 µs ┃  ± 26.90 µs ┃   408.3 % ┃
┃  (example chain2/execute false 50) ┃   2.16 ms ┃ ± 134.51 µs ┃   927.0 % ┃
┃ (example chain1/execute false 100) ┃   1.89 ms ┃  ± 62.11 µs ┃   810.6 % ┃
┃ (example chain2/execute false 100) ┃ 991.04 µs ┃  ± 53.19 µs ┃   424.5 % ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┻━━━━━━━━━━━┻━━━━━━━━━━━━━┻━━━━━━━━━━━┛

feels like PersistentQueue may be the way to go after all, gettting nth element
of a vector is too slow.

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━━┓
┃             Expression             ┃    Mean   ┃     Var     ┃  Ratio  ┃
┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╋━━━━━━━━━━━╋━━━━━━━━━━━━━╋━━━━━━━━━┫
┃   (example chain1/execute true 10) ┃ 299.00 µs ┃  ± 11.98 µs ┃ 128.7 % ┃
┃   (example chain2/execute true 10) ┃ 235.72 µs ┃   ± 6.02 µs ┃ 101.5 % ┃
┃   (example chain1/execute true 50) ┃ 271.39 µs ┃   ± 2.73 µs ┃ 116.9 % ┃
┃   (example chain2/execute true 50) ┃   2.23 ms ┃  ± 60.40 µs ┃ 959.1 % ┃
┃  (example chain1/execute true 100) ┃ 232.24 µs ┃ ± 653.58 ns ┃ 100.0 % ┃ (fastest)
┃  (example chain2/execute true 100) ┃   1.13 ms ┃  ± 40.31 µs ┃ 487.2 % ┃
┃  (example chain1/execute false 10) ┃   1.19 ms ┃  ± 43.36 µs ┃ 510.9 % ┃
┃  (example chain2/execute false 10) ┃   1.85 ms ┃  ± 50.32 µs ┃ 797.6 % ┃
┃  (example chain1/execute false 50) ┃ 964.75 µs ┃  ± 29.27 µs ┃ 415.4 % ┃
┃  (example chain2/execute false 50) ┃   2.23 ms ┃  ± 46.00 µs ┃ 961.8 % ┃ (slowest)
┃ (example chain1/execute false 100) ┃   1.89 ms ┃  ± 52.39 µs ┃ 815.1 % ┃
┃ (example chain2/execute false 100) ┃ 973.70 µs ┃  ± 28.41 µs ┃ 419.3 % ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┻━━━━━━━━━━━┻━━━━━━━━━━━━━┻━━━━━━━━━┛

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━━┓
┃             Expression             ┃    Mean   ┃     Var     ┃  Ratio  ┃
┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╋━━━━━━━━━━━╋━━━━━━━━━━━━━╋━━━━━━━━━┫
┃   (example chain1/execute true 10) ┃ 300.21 µs ┃  ± 12.59 µs ┃ 114.0 % ┃
┃   (example chain2/execute true 10) ┃ 263.24 µs ┃  ± 11.35 µs ┃ 100.0 % ┃ (fastest)
┃   (example chain1/execute true 50) ┃ 290.43 µs ┃  ± 15.45 µs ┃ 110.3 % ┃
┃   (example chain2/execute true 50) ┃   2.16 ms ┃ ± 142.63 µs ┃ 821.2 % ┃ (slowest)
┃  (example chain1/execute true 100) ┃ 265.68 µs ┃   ± 9.36 µs ┃ 100.9 % ┃
┃  (example chain2/execute true 100) ┃   1.08 ms ┃  ± 41.11 µs ┃ 408.5 % ┃
┃  (example chain1/execute false 10) ┃   1.13 ms ┃  ± 54.85 µs ┃ 428.5 % ┃
┃  (example chain2/execute false 10) ┃   1.86 ms ┃  ± 77.25 µs ┃ 704.8 % ┃
┃  (example chain1/execute false 50) ┃ 958.99 µs ┃  ± 44.39 µs ┃ 364.3 % ┃
┃  (example chain2/execute false 50) ┃   2.10 ms ┃  ± 78.32 µs ┃ 797.6 % ┃
┃ (example chain1/execute false 100) ┃   1.85 ms ┃  ± 69.48 µs ┃ 701.7 % ┃
┃ (example chain2/execute false 100) ┃ 960.76 µs ┃  ± 36.04 µs ┃ 365.0 % ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┻━━━━━━━━━━━┻━━━━━━━━━━━━━┻━━━━━━━━━┛

This has got me down because how can that old ugly broken code be faster?

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━━┓
┃             Expression             ┃    Mean   ┃     Var     ┃  Ratio  ┃
┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╋━━━━━━━━━━━╋━━━━━━━━━━━━━╋━━━━━━━━━┫
┃   (example chain1/execute true 10) ┃ 291.22 µs ┃   ± 4.23 µs ┃ 110.4 % ┃
┃   (example chain2/execute true 10) ┃ 267.34 µs ┃   ± 7.82 µs ┃ 101.4 % ┃
┃   (example chain1/execute true 50) ┃ 293.59 µs ┃  ± 18.86 µs ┃ 111.3 % ┃
┃   (example chain2/execute true 50) ┃   2.23 ms ┃ ± 109.84 µs ┃ 846.2 % ┃ (slowest)
┃  (example chain1/execute true 100) ┃ 263.75 µs ┃  ± 11.87 µs ┃ 100.0 % ┃ (fastest)
┃  (example chain2/execute true 100) ┃   1.05 ms ┃  ± 21.40 µs ┃ 398.7 % ┃
┃  (example chain1/execute false 10) ┃   1.15 ms ┃  ± 49.73 µs ┃ 437.8 % ┃
┃  (example chain2/execute false 10) ┃   1.90 ms ┃  ± 62.41 µs ┃ 719.1 % ┃
┃  (example chain1/execute false 50) ┃ 986.54 µs ┃  ± 21.83 µs ┃ 374.0 % ┃
┃  (example chain2/execute false 50) ┃   2.04 ms ┃  ± 45.58 µs ┃ 773.3 % ┃
┃ (example chain1/execute false 100) ┃   1.79 ms ┃  ± 29.31 µs ┃ 677.0 % ┃
┃ (example chain2/execute false 100) ┃ 927.77 µs ┃  ± 18.47 µs ┃ 351.8 % ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┻━━━━━━━━━━━┻━━━━━━━━━━━━━┻━━━━━━━━━┛

…ise. Odd!

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━━━┳━━━━━━━━━┓
┃             Expression             ┃    Mean   ┃     Var    ┃  Ratio  ┃
┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╋━━━━━━━━━━━╋━━━━━━━━━━━━╋━━━━━━━━━┫
┃   (example chain1/execute true 10) ┃ 294.55 µs ┃ ± 11.79 µs ┃ 113.0 % ┃
┃   (example chain2/execute true 10) ┃ 260.61 µs ┃  ± 9.16 µs ┃ 100.0 % ┃ (fastest)
┃   (example chain1/execute true 50) ┃ 290.55 µs ┃ ± 12.64 µs ┃ 111.5 % ┃
┃   (example chain2/execute true 50) ┃   2.14 ms ┃ ± 79.23 µs ┃ 819.3 % ┃ (slowest)
┃  (example chain1/execute true 100) ┃ 263.40 µs ┃ ± 10.36 µs ┃ 101.1 % ┃
┃  (example chain2/execute true 100) ┃   1.08 ms ┃ ± 40.20 µs ┃ 413.2 % ┃
┃  (example chain1/execute false 10) ┃   1.10 ms ┃ ± 45.12 µs ┃ 423.9 % ┃
┃  (example chain2/execute false 10) ┃   1.81 ms ┃ ± 68.63 µs ┃ 693.3 % ┃
┃  (example chain1/execute false 50) ┃ 940.31 µs ┃ ± 24.03 µs ┃ 360.8 % ┃
┃  (example chain2/execute false 50) ┃   2.06 ms ┃ ± 84.38 µs ┃ 789.3 % ┃
┃ (example chain1/execute false 100) ┃   1.82 ms ┃ ± 79.02 µs ┃ 697.4 % ┃
┃ (example chain2/execute false 100) ┃ 966.00 µs ┃ ± 32.83 µs ┃ 370.7 % ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┻━━━━━━━━━━━┻━━━━━━━━━━━━┻━━━━━━━━━┛

…just happy

things are relatively close.  More accurate results, perhaps, with the very slow bench (rather than the default
quick bench).

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━━━┳━━━━━━━━━━━┓
┃             Expression             ┃    Mean   ┃     Var    ┃   Ratio   ┃
┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╋━━━━━━━━━━━╋━━━━━━━━━━━━╋━━━━━━━━━━━┫
┃   (example chain1/execute false 5) ┃ 173.56 µs ┃  ± 2.30 µs ┃   100.6 % ┃
┃   (example chain2/execute false 5) ┃   1.76 ms ┃ ± 26.54 µs ┃ 1,022.5 % ┃
┃  (example chain1/execute false 10) ┃ 172.60 µs ┃  ± 1.88 µs ┃   100.0 % ┃ (fastest)
┃  (example chain2/execute false 10) ┃ 936.96 µs ┃ ± 42.44 µs ┃   542.9 % ┃
┃  (example chain1/execute false 50) ┃   2.06 ms ┃ ± 33.00 µs ┃ 1,193.7 % ┃
┃  (example chain2/execute false 50) ┃   1.07 ms ┃ ± 14.47 µs ┃   621.7 % ┃
┃ (example chain1/execute false 100) ┃   1.77 ms ┃ ± 26.09 µs ┃ 1,025.8 % ┃
┃ (example chain2/execute false 100) ┃ 256.64 µs ┃  ± 3.49 µs ┃   148.7 % ┃
┃    (example chain1/execute true 5) ┃   1.07 ms ┃ ± 15.58 µs ┃   621.5 % ┃
┃    (example chain2/execute true 5) ┃ 257.37 µs ┃  ± 3.40 µs ┃   149.1 % ┃
┃   (example chain1/execute true 10) ┃ 281.25 µs ┃  ± 4.07 µs ┃   162.9 % ┃
┃   (example chain2/execute true 10) ┃ 187.22 µs ┃  ± 2.95 µs ┃   108.5 % ┃
┃   (example chain1/execute true 50) ┃ 928.81 µs ┃ ± 14.83 µs ┃   538.1 % ┃
┃   (example chain2/execute true 50) ┃   2.07 ms ┃ ± 35.27 µs ┃ 1,197.0 % ┃ (slowest)
┃  (example chain1/execute true 100) ┃ 284.05 µs ┃  ± 4.73 µs ┃   164.6 % ┃
┃  (example chain2/execute true 100) ┃ 191.76 µs ┃  ± 3.14 µs ┃   111.1 % ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┻━━━━━━━━━━━┻━━━━━━━━━━━━┻━━━━━━━━━━━┛

Also, inlined function calls for speed

Now version 2 is nearly always faster than version 1

…ver.