Round Robin with Token Pool

[paulmansour]

Consider repeatedly selecting an item from a list where we always want the next item, and we reach the end, we go back to the beginning, a round-robin selection.

If we take the list and chuck it into the token pool:

      'ABCDE' ⎕TPUT¨5

And then get and put at the same time:

      f←{r⊣(r←⎕TGET 5) ⎕TPUT 5}

We can select via a round robin method:

      f 0
A
       f 0
B
       f 0
C
       f¨⍳10
DEABCDEABC

I thought this might be an overkill use of the token pool, but I think it might be faster than any other technique, and also avoids deciding where to store the list.

I am continually amazed at how I managed to live before the token pool came in to existence!