Never too late :pissed:
I've had to rename yours to gbn2, since there was a gbn already:Benchmarking ...........Elapsed milliseconds / relative speed for 256 iteration(s):
(LIST-GBN LST 5)...................1232 / 2.55 <fastest>
(GBN_1_EV LST 5)...................1294 / 2.42
(GROUPBYNUM_MAC3 LST 5)............1763 / 1.78
(LIST-GROUP-STEPREVERSE LST 5).....1794 / 1.75
(GROUPBYNUM_MAC4 LST 5)............2590 / 1.21
(LIST-GROUP LST 5).................2621 / 1.2
(_SUBLISTS LST 5)..................2652 / 1.18
(GBN2 LST 5).......................3027 / 1.04
(LM:GROUPBYNUM-R LST 5)............3120 / 1.01
(LM:GROUPBYNUM LST 5)..............3136 / 1
(GBN LST 5)........................3136 / 1 <slowest>
Not bad ... made the top 10!
Strange though, I did the previous test on another PC. Used the exact same test case:(setq lst nil n 0)
(repeat 5000 (setq lst (cons n lst) n (1+ n)))
The two PC's are extremely close to being identical (both i7-2600, both 16GB ram, both Win7 Pro, both Vanilla 2012). Yet there's some discrepancies in the benchmarking. I've run the benchmarking 5 times now and get similar results each time. Must be something strange running on the background in one but not the other.
Perhaps my AV, the 1st had ClamWin+MSSE, this one's got Avast!