hi guys, what type of programming feature that enables us to use `launch` and `delay` functions insi...

# coroutines

[altianogerung]

hi guys, what type of programming feature that enables us to use launch and delay functions inside coroutine?

fun main() = runBlocking { // this: CoroutineScope
    launch { // launch a new coroutine and continue
        delay(1000L) // non-blocking delay for 1 second (default time unit is ms)
        println("World!") // print after delay
    }
    println("Hello") // main coroutine continues while a previous one is delayed
}

[reactormonk]

Which kinda name are you looking for? red/blue functions? suspend? Coroutines?

[altianogerung]

no, the launch and delay methods, why we can access them?

[reactormonk]

Ah, Kotlin allows you to set a scope for blocks, so lauch is basically

kotlin
runBlocking { scope ->
  scope.launch { ...

AFAIK

[reactormonk]

Ah right, markdown in Slack is still barebones 😞

[altianogerung]

isee, so it’s actually the property of the first parameter in lambda functions..
is it only for first parameter that we can refer its property or for any parameters? could u point me to some docs?

[reactormonk]

I think you gotta do some more than just first parameter, but don't have any docs at the ready.

[altianogerung]

it’s probably called extension function,,
which extends CoroutineScope
🤔🤷‍♂️

[Riccardo Lippolis]

I think you might be looking for the term "function literal with receiver".

The runBlocking function takes such an argument (the code block that you supply) in the form block: suspend CoroutineScope.() -> T. So inside the code block you provide to the runBlocking function, CoroutineScope becomes the implicit this, meaning that you can call functions from the CoroutineScope class, like launch and delay . The runBlocking function then runs your code block, in the context of an instance of CoroutineScope.

[Loney Chou]

Note that delay is just a regular suspend function.