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  • $\begingroup$ @Xavier Thanks. Glad you liked it. You can search the site for dynP function of Mr.Wizard, which has comparable performance to Internal`PartitionRagged, while being implemented purely in top-level code. $\endgroup$ Commented Aug 29, 2015 at 1:45
  • $\begingroup$ Neat, but fails when negatives present. +1 though. Interestingly, dramatic slowdown with reals. $\endgroup$ Commented Aug 29, 2015 at 4:09
  • $\begingroup$ @ciao Thanks. It does work with negative numbers, for me. Can you provide an example where it fails for you? Re: slowdown - indeed. Probably related to the auto-compilation, although I still don't understand why - by default the arguments of compiled function are anyway reals. $\endgroup$ Commented Aug 29, 2015 at 13:35
  • $\begingroup$ @ciao One guess would be that, for integers, the list of 4 elements produced at each iteration of Fold, can still be packed, and is packed since Fold auto-compiles. For reals, the list contains 2 integers and 2 reals, and so can't be packed. Not sure if I am right, but I can't see any better explanation at the moment. One thing that kind of confirms my guess is that if you use N@{0, 0, 0, 0} as a starting value in FoldList, instead of {0, 0, 0, 0}, then the performance on integers also degrades just like it does for reals. $\endgroup$ Commented Aug 29, 2015 at 13:41
  • $\begingroup$ @LeonidShifrin: Range[-3,3] trivial example - s/b 7 distinct sets, but output is just the range... $\endgroup$ Commented Aug 29, 2015 at 19:20