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> Sadly Rust is in fact getting mroe more complex all the time though, with things like async/await added and other complex features in the pipeline (like speci

> Sadly Rust is in fact getting mroe more complex all the time though, with things like async/await added and other complex features in the pipeline (like specialization, higher kinded types, generators, ...). Some of those have fairly simple semantics though. Generators are really just very a very big enum, with a function moving through the different states of the enum. Async/await is just a fancy name for a generator that returns a Poll. Specialization is very constrained - it only applies to trait methods qualified with "default"), but I agree the current rules around it are rather complex, and they aren't even sound so they'll probably get even more complex. HKT has no concrete plan so it's hard to know how much mental overhead it will add. But it's likely to be very non-trivial too.

the_duke 7y ago
> Some of those have fairly simple semantics though. I'd disagree with that. Yes technically, a generator is just a enum representing a state machine that can be stepped through. And async/await is just a generator with some extra compiler utility. But they completely change how code is executed, to the point that you don't really think about it as a state machine and have to work hard (mentally) to reconstruct what is happening under the hood. Debugging gets much more complex. And it also adds another part that you need to understand and work with. Async/await is particularly bad because it's not a standalone feature: it comes with a large ecosystem of crates that provide streams, executors, reactors, timers, .... It's a huge strain on the complexity budget.