miniblog.

Language design question: what type should `while True {}` have? Bottom: It doesn't contain any `break` statements. Unit: Treat loops with/without `break` consistently. I already have lints that warn on unreachable code after diverging loops, so the Unit case feels surprising.

@krinkle A surprising number of PL design workarounds are "just add another equals sign" 🙃

I tried replace Vec with SmallVec in a really hot loop in difftastic, and it's a huge speedup. It almost *halved* the runtime of one of my test files! I've done a lot of performance tuning of difftastic, so it's surprising to see such a big win. https://crates.io/crates/smallvec