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Derek Berner
05/17/2019, 7:56 PMBack. Went to get coffee. Is there a distinction between invoking and executing a suspend function? - p
pakoito
05/17/2019, 7:57 PMno - p
pakoito
05/17/2019, 7:57 PMso in our lingo you can invoke functions or use flatMap to extract values - p
pakoito
05/17/2019, 7:57 PMbut the program won’t start doing it until you run it - p
pakoito
05/17/2019, 7:57 PMand I don’t mean starting the app, or getting to the main - p
pakoito
05/17/2019, 7:58 PMbut using runBlocking, runNonBlocking, unsafeRunAsync etc. - p
pakoito
05/17/2019, 7:58 PMthe one closest to the entry point of the program - p
pakoito
05/17/2019, 7:58 PMyou can only invoke a suspend function inside a suspend function - p
pakoito
05/17/2019, 7:58 PMor at the edge of the program with the run functions I’ve just mentioned - d
Derek Berner
05/17/2019, 7:59 PMso it's about chaining suspends all the way to the edge of the program🔝 2 - p
pakoito
05/17/2019, 7:59 PMyep - p
pakoito
05/17/2019, 7:59 PMthe snippets above are just duct-taping two separate runtimes - p
pakoito
05/17/2019, 7:59 PMone being suspend functions and the other IO - d
Derek Berner
05/17/2019, 8:02 PMbecause you can't call suspend from a pure function without some higgledy-piggledy like runBlocking or unsafeRunSync - p
pakoito
05/17/2019, 8:02 PMyep, and there’s supposed to be one of those per program (or Activity on Android) - d
Derek Berner
05/17/2019, 8:04 PMSo
is really just converting between invocation stylessuspendCoroutine{unsafeRunAsync{}} - p
pakoito
05/17/2019, 8:04 PMso you have to create a new “edge of the program” between the runtimes - p
pakoito
05/17/2019, 8:04 PMyep - p
pakoito
05/17/2019, 8:04 PMin RxJava and Reactor it’s Observable/Flux/Single/`.create` - p
pakoito
05/17/2019, 8:05 PMCopy codefun <A> (suspend () ->A).toObservable(): Observable<A> = Observable.create { emitter -> this.startCoroutine(Continuation(EmptyCoroutineContext) { result -> result.fold({ a -> emitter.onNext(a); emitter.onComplete() }, emitter::onError) }) } - d
Derek Berner
05/17/2019, 8:07 PMPut another way, it's fine to do unsafe IO from within
because that's whatIO
is forIO - p
pakoito
05/17/2019, 8:08 PMthat’s what the async constructor is for, yeah, for wrapping side-effecting asynchronous code - d
Derek Berner
05/17/2019, 8:08 PMI think I was just struggling on the pure/impure language - p
pakoito
05/17/2019, 8:08 PMto wrap side-effecting synchronous code we have the constructor delay - p
pakoito
05/17/2019, 8:09 PMat this point it’s been a couple of years since I wrote the glossary and I’m so deep on this shit that I don’t know what’s easy and what’s hard anymore➕ 1 - p
pakoito
05/17/2019, 8:09 PMthat’s why we need external contributors of any level➕ 1 - p
pakoito
05/17/2019, 8:09 PMto add to the learning experience - d
Derek Berner
05/17/2019, 8:10 PMdoes delay go into a thread pool? - p
pakoito
05/17/2019, 8:10 PMonly if you tell it to - p
pakoito
05/17/2019, 8:11 PMthe default is no asynchrony