range chunks

[bearophile]

Philippe Sigaud:
> Here is what I cooked, it's still a bit rough around the edges. It has an
> optional step argument, to see how many elements to jump.

It's better to give it a default chunk size of 2.
If I have understood this well, then this is the partition() function:
http://reference.wolfram.com/mathematica/ref/Partition.html

If you want to be more complete you can add two more features: to start counting items from the end (but they are given from the start) and give a "duplication window", so for example the natural numbers with a window of 2 and a duplication of 1 are [1, 2], [2, 3], [3, 4]. But adding too many features risks to produce functions like the Mathematica ones, that sometimes are hard to use because they have tons of complex arguments.)

Bye,
bearophile