The for loop "knows" how many items there are in a list and assigns every one item from that list to thesome_meaningful_word_you_choose. Ideally, you pick a word that is meaningfull to your and your team. Often you choose a characteriorkeyfor that purpose. But you can pick whatever ...
meaning you have to write a recursive function just to match over it -- e.g. here's a function I wrote for a partial solution that fixes the first two false-negatives above but not the third one: