<https://kotlinlang.org/docs/inline-functions.html...

# getting-started

[anlex N]

https://kotlinlang.org/docs/inline-functions.html

If I use crossinline, I only can use variables in the f body, right? or how to better understand crossinline ? what is non-local returns?

[gildor]

This section of the doc has explanation of non-local return

[gildor]

Not sure that I understand question about variables In function f
Crossiline means that lambda body will not be inlined, even thought it's a part of inline function, because it used by some context where it's not possible (like in example of the code, where it's called in a body of another anonymous class)
As result, crossiline lambda have other limitations of non-inline functions, because they are not a part of body of the function, and cannot return from it

[anlex N]

fun f and val f , Why use it this way？so crazy, oh my god.

[gildor]

Be free to edit page, it's indeed unnecessary confusing
No need to over react

[gildor]

My answer still stands, there is no limitation on usage of anything inside of Runnable implementation except what is usually limited for normal methods or classes, like return from parent context

[anlex N]

the enclosing function mean foo or ordinaryFunction?

[Miroljub Enjaković [EpicGuy4000]]

enclosing function in this context means foo

[Miroljub Enjaković [EpicGuy4000]]

fun foo() {
    ordinaryFunction {
        return@foo // ERROR: cannot make `foo` return here
    }
}

fun foo() {
    ordinaryFunction {
        return@ordinaryFunction // Success
    }
}

Here is a labeled version of that code

[anlex N]

based on your words, body can not use return , label syntax, and exit f, right?

[Miroljub Enjaković [EpicGuy4000]]

In the words of the documentation, body can only use labeled return for the local lambda

fun foo() {
    f {
        println("foo.f.body")
        return@f
    }
}

inline fun f(crossinline body: () -> Unit) {
    val f = object: Runnable {
        override fun run() = body()
    }
    f.run()
}

fun main() {
    foo()
}