effing-mad

super cool! i’m really bullish on coroutines as a way of isolating state machines from actual mutations of state. i.e. doing pretty much what you’ve done here but for all sorts of business logic. another cool rust project messing with coroutines is effing-mad [0] which implements an effects system on top of them. on the actual implementation, i’m curious as to why you return the coroutine boxed, rather than as an RPIT? i feel that could potentially lead to some missed optimizations, but probably nothing significant. [0]: https://github.com/rosefromthedead/effing-mad

> Do you also count heap allocations as side effects to be externalized? I’ve gone back and forth on heap. I admire Zig’s handling of allocation failures, but I’d also like to use Rust’s alloc lib. I’m currently leaning towards allocation and printing to stderr being available under any context. > Async/await in Rust is just stackless coroutines Yup, it was actually through Rust’s async that I learned about stackless coroutines. There’s a really fun rust crate [0] that implements effects with Rust’s nightly coroutine feature. [0]: https://github.com/rosefromthedead/effing-mad