3 ms·

You need more than that for the example with setTimeout(). It requires to be able to freeze the stack and then go back later. You need stackful coroutine (like

You need more than that for the example with setTimeout(). It requires to be able to freeze the stack and then go back later. You need stackful coroutine (like goroutine) for that.

tome 4mo ago
That's very interesting, thanks! It gave me a brainwave and I wondered I could implement that in Bluefin. I'm pretty sure Bluefin's Request[1] is a second class stackful coroutine, and sure enough it turns out to be possible, so I'm pleased about that. -- ghci> example -- Hello -- World -- Timed out example = runEff $ \io -> awaitYield (receiver io) sender receiver :: (e1 <: es, e2 <: es) => IOE e1 -> Await String e2 -> Eff es () receiver io a = do r1 <- await a effIO io (putStrLn r1) r2 <- await a effIO io (putStrLn r2) mr3 <- timeout io 0 (await a) effIO io $ case mr3 of Nothing -> putStrLn "Timed out" Just r3 -> putStrLn r3 sender :: e1 <: es => Yield String e1 -> Eff es () sender y = do yield y "Hello" yield y "World" yield y "More" timeout :: e1 <: es => IOE e1 -> Int -> Eff es r -> Eff es (Maybe r) timeout io t m = withEffToIO (\effToIO -> System.Timeout.timeout t (effToIO (\_ -> useImpl m))) io
mjmas 4mo ago
Or in Lua you'd wrap the initial call in a coroutine, possibly with coronest[a] or something similar to make handling the effects at the right layer easier. And so then the outer code is a loop around coroutine.resume, and the inner code uses coroutine.yield to perform an effect. [a]: https://github.com/saucisson/lua-coronest https://github.com/saucisson/lua-coronest