Let it snow

You might have seen John Scholes’ quietly famous implementation (in Dyalog APL) of Conway’s Game of Life. We’re going to explore just one of the array-language features in it, indexing one array with another. You can use TryAPL.org to experiment. The principle seems simple enough.

from My Pocket https://arraythinking.wordpress.com/2015/12/20/let-it-snow/