What's the deal with `return` followed by @ and reference to outer block?

Question

There are multiple occurrences of return@something, like the following:

    withContext(Dispatchers.IO) {
        doSomething(task)
        return@withContext action(task)
    }

what does this @withContext mean? If I try to move return up, like this, it does not compile:

    return withContext(Dispatchers.IO) {
        doSomething(task)
        action(task)
    }

Answer 1

withContext calls the specified suspending block with a given coroutine context, suspends until it completes, and returns the result.

https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines/with-context.html