@diesieben07 can I consider this syntax

->

in lamdas as return?

Not quite. The return value of a lambda is usually it's last expression: https://kotlinlang.org/docs/reference/lambdas.html#returning-a-value-from-a-lambda-expression

What does the

@lit

use for?

Usually

return@filter

, making a return to another scope

@edwardwongtl where can I find those annotation documentation?

That’s not quite a annotation, search for

Non-local return

@edwardwongtl non-local return is useful if you still want to process something after return is it?

It is useful when you are nesting too much lambdas

I have an issue here. How come these two produce different outcomes?

fun foo() {
    run loop@{
        listOf(1, 2, 3, 4, 5).forEach {
            if (it == 3) return@loop // non-local return from the lambda passed to run
            print(it)
        }
    }
    print(" done with nested loop")
}

12 done with nested loop

fun foo() {
    run {
        listOf(1, 2, 3, 4, 5).forEach {
            if (it == 3) return@forEach
            // non-local return from the lambda passed to run
            print(it)
        }
    }
    print(" done with nested loop")
}

1245 done with nested loop

return@forEach

actually work as

continue

@edwardwongtl This line of code is similar like

continue

or

return@forEach

right?

fun foo() {
    listOf(1, 2, 3, 4, 5).forEach lit@{
        if (it == 3) return@lit // local return to the caller of the lambda, i.e. the forEach loop
        print(it)
    }
    print(" done with explicit label")
}

fun main(args: Array<String>) {
    foo()
}

You might want the docs for labels and using return with them https://kotlinlang.org/docs/reference/returns.html