miniblog.

TIL Advent of Code and Project Euler will deliberately look for puzzles where the naive solution is worse than quadratic. This ensures that people can solve them with any programming language. You don't want fast languages to be able to use the naive solution.

It's incredibly hard to explain adversarial problems to users. I see gamers sincerely asking "why doesn't the publisher just fix the cheater problem?". This is exacerbated by the fact that sharing too many details of anticheat can make the problem worse.

I'm having fun writing a simple type checker, but I'm learning firsthand why syntax-directed checking doesn't work. It prevents inference. My checker catches real bugs, but it can't handle cases like this: [1, 2].map(fun(x) { x + 1; }) I think I need bidirectional checking.