nice :) also see here:

https://news.ycombinator.com/item?id=45603661

HN is such a sweetheart. i should check in more often.

> t=\:t:!x

this is of course obvious first idea, but the recipe from above is actually from the official k4 cookbook. t=t is less innocent than it seems, i'm afraid.

in k7/k9, we can:

  10^@[100#0.;11*!10;1.]    /just for more lulz

there's also a way to mutate it in place!