[Dylan16807]

> It's almost as if there's two fundamentally different types of functions that people might want to declare, necessitating two function colors.

Since any function can get indefinitely stuck in a system call, the main difference between "sync" and "async" isn't whether you can pause execution, it's who can pause execution. And the main downside to the more flexible option is that it requires extra overhead in how the stack gets allocated.

But why should the flexible/inflexible choice be made on a per-function basis? I feel like I'm manually annotating which functions will inline, except worse because certain combinations won't compile. Instead, how about having the compiler figure it out on a per-call basis?