Coroutines is just a way to write continuations in an imperative style and with more overhead.

I never understood the value. Just use lambdas/callbacks.

> Just use lambdas/callbacks

"Just" is doing a lot of work there. I've use callback-based async frameworks in C++ in the past, and it turns into pure hell very fast. Async programming is, basically, state machines all the way down, and doing it explicitly is not nice. And trying to debug the damn thing is a miserable experience

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mgaunard 3 hours ago | parent [-]

You can embed the state in your lambda context, it really isn't as difficult as what people claim.

The author just chose to write it as a state machine, but you don't have to. Write it in whatever style helps you reach correctness.

	▲	Sharlin 3 hours ago \| parent [-]
		You still need the state and the dispatcher, even if the former is a little more hidden in the implicit closure type.

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affenape 3 hours ago | parent | prev | next [-]

Not necessarily. A coroutine encapsulates the entire state machine, which might pe a PITA to implement otherwise. Say, if I have a stateful network connection, that requires initialization and periodic encryption secret renewal, a coroutine implementation would be much slimmer than that of a state machine with explicit states.

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jayd16 2 hours ago | parent | prev | next [-]

You can structure coroutines with a context so the runtime has an idea when it can drop them or cancel them. Really nice if you have things like game objects with their own lifecycles.

For simple callback hell, not so much.

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spacechild1 2 hours ago | parent | prev | next [-]

> Just use lambdas/callbacks.

Lol, no thanks. People are using coroutines exactly to avoid callback hell. I have rewritten my own C++ ASIO networking code from callback to coroutines (asio::awaitable) and the difference is night and day!

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Sharlin 3 hours ago | parent | prev | next [-]

Did you read the article? As the author says, it becomes a state machine hell very quickly beyond very simple examples.

	▲	kccqzy 2 hours ago \| parent [-]
		I just don’t agree that it always becomes a state machine hell. I even did this in C++03 code before lambdas. And honestly, because it was easy to write careless spaghetti code, it required a lot more upfront thought into code organization than just creating lambdas willy-nilly. The resulting code is verbose, but then again C++ itself is a fairly verbose language.

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DonHopkins 2 hours ago | parent | prev [-]

The Unity editor does not let you examine the state hidden in your closures or coroutines. (And the Mono debugger is a steaming pile of shit.)

Just put your state in visible instance variables of your objects, and then you will actually be able to see and even edit what state your program is in. Stop doing things that make debugging difficult and frustratingly opaque.

	▲	jayd16 an hour ago \| parent [-]
		Use Rider or Visual Studio. Debugging coroutines should be easy. You just can't step over any yield points so you need to break after execution is resumed. It's mildly tedious but far from impossible.