Ask HN: What's Paul Graham been up to?
It's been a while since I've seen any posts or new PG essays--just wondering if we can expect anything soon? :)
Other than that he's probably just enjoying spending quality time with his young family after a relentlessly busy few years.
https://news.ycombinator.com/threads?id=pg
However, he is very active on Twitter
(let a 1 b 2 c 3 (+ a b c)) -> 6.
Note how there can only be one form, otherwise it is ambiguous. But when you have two or more forms in a construct ("implicit progn"), all but the last are evaluated purely for their side effects (pun intended): it is imperative programming, which this new form of let nicely banishes.Actually, that's not true. You can disambiguate multiple forms by noting that variables are atoms while forms are lists.
(Personally, I think it's very bad practice to use a symbol macro that expands to anything other than a place, and it's certainly bad practice to define a symbol macro that expands to a form with side-effects. So this would never happen in my code. YMMV of course.)