hi ``` i am confuse with this syntax fun task bloc suspend g

Question

hi ``` i am confuse with this syntax fun task bloc suspend gt Unit ``` what does mean call suspend function inside regular function

octylFractal · Answer

That tells the compiler to make `bloc` a `suspend` lambda i e you need to call `bloc` from a suspend function it doesn t matter if the parameter is on a regular function because the function isn t calling `bloc`

halim · Answer

not clear can you make an example to explain your idea

simon.vergauwen · Answer

There is no way to know that You can run suspend functions using `startCoroutine` with a callback

halim · Answer

yes i know about how to call this suspend func but why declare it suspend in regular fun

simon.vergauwen · Answer

Well it could be a fire and forget scenario

halim · Answer

more details i possible

simon.vergauwen · Answer

task runs the suspend bloc function with a callback using startCoroutine

octylFractal · Answer

``` fun lt T gt runSomethingTwice block suspend gt T T = runBlocking block block ``` this function calls `block ` which may need to suspend it uses some suspending resource twice using `runBlocking` to provide a CoroutineScope suspend context

simon.vergauwen · Answer

That s one of the many possible scenarios

octylFractal · Answer

it just means the lambda can t be used in a normal context you need some suspending context to call it

octylFractal · Answer

in this case I ve used `runBlocking` to get such a context but there are other options like `async` and `launch`

halim · Answer

so if i understand the purpose of use suspend inside regular is to avoid to blocking the caller thread of regular fun and wrap this suspend inside scope and dispatch in other thread

octylFractal · Answer

no the regular function may still block as in my case but it could also hand it off to `launch` or `async` in which case it wont

halim · Answer

so if wrap regular fun in scope with async launch it becomes async fun so how about implemenation of coroutine builder launch async runbloking flow its not wrap in any scope just run suspend inside so how explain suspend usage in cooutine builder launch async runblocking flow

gildor · Answer

gt if wrap regular fun in scope with async launch it becomes async fun It s incorrect function is still syncronous and cannot suspend gt so how about implemenation of coroutine builder launch async runbloking flow If you interested how it implemented check sources or even better coroutines design reference which has simple veraions of those builders under the hood they use low level coroutine builders provided by stdlib which used to create coroutine from common callback based asyncronous code

gildor · Answer

This is more specific questions how existing Coroutine builders are work really recommend check this this document you want to know it in details <https github com Kotlin KEEP blob master proposals coroutines md> But your original question was about suspend lambda and as mentioned in this thread there are many usecases and it not limited by coroutine builder In general suspend lamdba is just a lamda that can be invoked only from suspend function same way as suspend function

halim · Answer

thanks for response so how about this snapshot ``` fun CoroutineScope someCall = launch println inside some call main = runblocking println before someCall println done ``` when execute before gt done gt inside some call so when wrap regular fun someCall in coroutine scope it become asynchrone

gildor · Answer

How this related to your original question

gildor · Answer

Also of course it s asyncronous because function someCall creates new coroutine that just started this is completely different from your original snippet

halim · Answer

yes exaalty what i want to say

gildor · Answer

Okay but how this related to your original question than

halim · Answer

its not depend i will read a topic about kotlin keep

halim · Answer

thanks for your time