13:40 <viaken> I think I don't understand dynamic scope, or how (let) works. Why is Guard keeping its rotation in subsequent calls of my (solve-1) here? (Advent of Code spoilers) https://git.sr.ht/~dpflug/advent/tree/trunk/item/2024/6.l#L27

13:43 <abu[7]> Guard is a "free" variable in drawOnFloor

13:44 <abu[7]> It is "bound" dynamically in solve-1

13:46 <abu[7]> 'let' saves the values of the symbol(s) in a stack frame and sets new values

13:47 <abu[7]> All code (no matter where) that accesses these symbols during that *time* sees these values

13:49 <abu[7]> '() is a bit redundant

13:49 <abu[7]> NIL is enough ;)

13:53 <abu[7]> Like "(let (Out '()) ..." should be "(let Out NIL ..."

13:54 <abu[7]> (I'm too pedantic about code size ;)

13:55 <viaken> Ah, of course.

13:59 <abu[7]> The whole .. (queue 'Out .. (pack Out) can in newer pil's be replaced with (pack (make (output (link @@) ...

14:00 <abu[7]> But as the result of (drawOnFloor) seems to be not used, the whole packing can be left out, no?

14:01 <viaken> Yep. I'm still vague on the various styles of printing.

14:02 <abu[7]> good

14:27 <viaken> The larger inefficiency is that I'm storing visits twice when printing, but I'll get that later when refactoring for part 2.

14:36 <viaken> Thank you for the tips!

14:50 <abu[7]> ☺